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InfoMagic Standards 1994 January
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.\" Troff code generated by TPS Convert from ITU Original Files
.\" Not Copyright ( c) 1991
.\"
.\" Assumes tbl, eqn, MS macros, and lots of luck.
.TA 1c 2c 3c 4c 5c 6c 7c 8c
.ds CH
.ds CF
.EQ
delim @@
.EN
.nr LL 40.5P
.nr ll 40.5P
.nr HM 3P
.nr FM 6P
.nr PO 4P
.nr PD 9p
.po 4P
.rs
\v | 5i'
.ce 1000
ANNEX\ B
.ce 0
.ce 1000
(to Recommendation Q.931)
.EF '% Fascicle\ VI.11\ \(em\ Rec.\ Q.931''
.OF '''Fascicle\ VI.11\ \(em\ Rec.\ Q.931 %'
.sp 9p
.RT
.ce 0
.ce 1000
\fBCompatibility checking\fR
.sp 1P
.RT
.ce 0
.LP
\fR B.1
\fIIntroduction\fR
.sp 1P
.RT
.PP
This Annex describes the various compatibility checks which should be carried
out to ensure that the best matched user and network capabilities are achieved
on a call within an ISDN.
.PP
This Annex also covers interworking with existing networks.
.PP
Three different processes of compatibility checking shall be
performed:
.RT
.LP
i)
at the user\(hyto\(hynetwork interface on the calling side (see
\(sc B.2);
.LP
ii)
at the network\(hyuser interface on the called side (see
\(sc B.3.2); and
.LP
iii)
user\(hyto\(hyuser (see \(sc B.3.3).
.PP
\fINote\fR \ \(em\ In this context and throughout this Annex the term \*Qcalled
user\*U is the end point entity which is explicitly addressed. This may
be an
addressed interworking unit (IWU), see I.500\(hySeries Recommendations.
.PP
For details on the coding of the information required for
compatibility checking, see Annex\ L.
.RT
.sp 1P
.LP
B.2
\fICalling side compatibility checking\fR
.sp 9p
.RT
.PP
At the calling side, the network shall check that the bearer
service requested by the calling user in the Bearer capability information
element matches with the bearer services provided to that user by the network.
If a mismatch is detected, then the network shall reject the call using
one of the causes listed in \(sc\ 5.1.5.2.
.PP
Network services are described in Recommendations I.230 [47] and I.240
[48] as bearer services and teleservices, respectively.
.RT
.sp 1P
.LP
B.3
\fICalled side compatibility checking\fR
.sp 9p
.RT
.PP
In this section, the word \*Qcheck\*U means that the user examines the
contents of the specified information element.
.RT
.sp 1P
.LP
B.3.1
\fICompatibility checking with addressing information\fR
.sp 9p
.RT
.PP
If an incoming SETUP message is offered with addressing
information (i.e.,\ either DDI or sub\(hyaddressing or the appropriate
part of the called party number, e.g.,\ for DDI) the following actions will
occur:
.RT
.LP
a)
if a number (e.g. for DDI) or sub\(hyaddress is assigned to a
user, then the information in a Called party number or Called
party sub\(hyaddress information element of the incoming call shall
be checked by the user against the corresponding part of the
number assigned to the user (e.g.,\ for DDI) or the user's own
sub\(hyaddress. In the case of a mismatch, the user shall
ignore the call. In the case of match, the compatibility
checking described in \(sc\(sc\ B.3.2 to B.3.3 will follow;
.LP
b)
if a user has no DDI number or sub\(hyaddress, then the Called
party number and Called party sub\(hyaddress information element
shall be ignored. The compatibility checking described in
\(sc\(sc\ B.3.2 and B.3.3 will follow.
.PP
\fINote\ 1\fR \ \(em\ According to the user's requirements, compatibility
checking can be performed in various ways from the viewpoint of execution
order and information to be checked, e.g.\ first DDI number/sub\(hyaddress
and then
compatibility or vice versa.
.PP
\fINote\ 2\fR \ \(em\ If an incoming call, offered with addressing information,
is always to be awarded to the addressed user, all users connected
to the same passive bus should have a DDI number or sub\(hyaddress.
.bp
.RT
.sp 1P
.LP
B.3.2
\fINetwork\(hyto\(hyuser compatibility checking\fR
.sp 9p
.RT
.PP
When the network is providing a bearer service at the called side, the
user shall check that the bearer service offered by the network in the
Bearer capability information element matches the bearer services that
the user is able to support. If a mismatch is detected, then the user shall
either
ignore or reject the offered call using cause No.\ 88, \fIincompatible\fR
\fIdestination\fR .
.RT
.sp 1P
.LP
B.3.3
\fIUser\(hyto\(hyuser compatibility checking\fR
.sp 9p
.RT
.PP
The called side terminal equipment shall check that the content of the
Low layer compatibility information element is compatible with the
functions it supports.
.PP
The Low layer compatibility information element (if available)
shall be used to check compatibility of low layers (e.g.,\ from layer\ 1 to
layer\ 3, if layered according to the OSI model).
.PP
\fINote\fR \ \(em\ The Bearer capability information element is also checked,
see \(sc\ B.3.2. Therefore, if any conflict from duplication of information
in the Bearer capability and the Low layer compatibility information elements
is
detected, this conflict shall be resolved according to Annex\ L, e.g.,\ the
conflicting information in the Low layer compatibility information element
shall be ignored.
.PP
If the Low layer compatibility information element is not included
in an incoming SETUP message, the Bearer capability information element
shall be used to check the compatibility of low layers.
.PP
The called terminal equipment may check the High layer
compatibility information element (if present) as part of user\(hyto\(hyuser
compatibility checking procedures, even if the network only supports bearer
services.
.PP
If a mismatch is detected in checking any of the information
elements above, then the terminal equipment shall either ignore or reject
the offered call using cause No.\ 88, \fIincompatible destination\fR .
.PP
With regard to the presence or absence of the High layer compatibility
and Low layer compatibility information elements, two cases arise:
.RT
.LP
a)
\fICompatibility assured with the available description\fR \fIof the call\fR
.LP
This is when all terminal equipment implement
(i.e.\ understand the contents of) the High layer compatibility
and Low layer compatibility information elements. Thus, based on
the High layer compatibility and Low layer compatibility
information element encoding, they are capable of accepting a
call for which they have the requested functionality.
.LP
b)
\fICompatibility not assured with the available description\fR
\fIof the call\fR
.LP
This is when all or some of the terminal equipment do not
recognize (i.e.\ ignore) either the High layer compatibility or
Low layer compatibility information elements. Without careful
configuration or administration at the user's installation,
there is a danger that a terminal equipment which has incorrect
functionality will accept the call.
.PP
Therefore, in order to assure compatibility with incoming calls, it is
recommended that the terminal equipment check the Low layer compatibility
and High layer compatibility information elements.
.PP
\fINote\fR \ \(em\ Some terminal equipment, upon bilateral agreement with
other users or in accordance with other standards (e.g.,\ Recommendation\
X.213\ [23]) may employ the User\(hyuser information element for additional
compatibility checking. Such terminal equipment shall check the User\(hyuser
information element in a manner identical to that described here for the
High layer compatibility information element \*Qcompatibility assured\*U
case.
.RT
.sp 1P
.LP
B.3.4
\fIUser action tables\fR
.sp 9p
.RT
.PP
Tables B\(hy1/Q.931, B\(hy2/Q.931 and B\(hy3/Q.931 show the action which
shall be carried out as a result of compatibility checking with the calling
user's request for a bearer service and/or teleservice.
.bp
.RT
.LP
.ce
\fBH.T. [T177.931]\fR
.ce
TABLE\ B\(hy1/Q.931
.ce
\fBBearer capability compatibility checking\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(60p) | cw(60p) | cw(96p) .
BC mandatory info element {
Point\(hyto\(hypoint data link
(Note 1)
} Broadcast data link (Note 1)
_
.T&
lw(60p) | lw(60p) | cw(96p) .
Compatible Proceed Proceed
_
.T&
lw(60p) | lw(60p) | lw(48p) | lw(48p) .
Incompatible Reject (\(sc 5.2.5.1) {
Ignore (\(sc 5.2.5.1 | ))
(Note 2)
} {
Reject (\(sc 5.2.5.1 | ))
(Note 2)
}
_
.TE
.nr PS 9
.RT
.ad r
\fBTable B\(hy1/Q.931 [T177.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.ce
\fBH.T. [T178.931]\fR
.ce
TABLE\ B\(hy2/Q.931
.ce
\fBLow layer and high layer compatibility checking: compatibility
.ce
assured\fR
.ce
\fBwith the available description of the call\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(36p) | cw(78p) | cw(114p) .
LLC/HLC compatibility assured {
Point\(hyto\(hypoint data link
(Note 1)
} Broadcast data link (Note 1)
_
.T&
cw(36p) | cw(78p) | cw(114p) .
Compatible Accept Accept
_
.TE
.TS
center box ;
lw(36p) | lw(30p) | lw(48p) | lw(36p) | lw(36p) | lw(42p) .
Incompatible Reject (\(sc 5.2.5.1) {
Attempt low layer compatibility negotiation
(Annex M)
} {
Ignore
(\(sc 5.2.5.1 | ))
(Note 2)
} {
Reject
(\(sc 5.2.5.1 | ))
(Note 2)
} {
Attempt low layer compatibility negotiation
(Annex M)
}
_
.TE
.nr PS 9
.RT
.ad r
\fBTable B\(hy2/Q.931 [T178.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.ce
\fBH.T. [T179.931]\fR
.ce
TABLE\ B\(hy3/Q.931
.ce
\fBLow layer and high layer compatibility checking: compatibility not\fR
.ce
.ce
\fBassured with the available description of the call\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(46p) | cw(94p) | cw(88p) .
{
LLC/HLC compatibility not assured
} {
Point\(hyto\(hypoint data link
(Note 1)
} Broadcast data link (Note 1)
_
.T&
lw(46p) | lw(46p) | lw(48p) | lw(40p) | lw(48p) .
HLC or LLC present Accept or reject (Note 3) {
Attempt low layer compatibility negotiation (Annex M)
} Accept or reject (Note 3) {
Attempt low layer compatibility negotiation
}
.TE
.LP
(Annex M)
\fINote\ 1\fR
\ \(em\ For broadcast data link terminal equipment which are explicity
addressed using sub\(hyaddressing or DDI, the point\(hyto\(hypoint column in
Tables\ B\(hy1/Q.931, B\(hy2/Q.931 and\ B\(hy3/Q.931 shall be used.
.LP
\fINote\ 2\fR
\ \(em\ When a terminal equipment on a broadcast data link is incompatible, an option of <<ignore or reject>> is permitted. (See \(sc\ 5.2.2).
.LP
\fINote\ 3\fR
\ \(em\ Some terminal equipment on this interface may understand the High
layer compatibility or Low layer compatibility information element and would
reject the call if incompatible.
.nr PS 9
.RT
.ad r
\fBTable B\(hy3/Q.931 [T179.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 1P
.LP
B.4
\fIInterworking with existing networks\fR
.sp 9p
.RT
.PP
Limitations in network or distant user signalling (e.g.\ in the case of
an incoming call from a PSTN or a call from an analogue terminal) may
restrict the information available to the called user in the incoming SETUP
message. A called user should accept limited compatibility checking
(e.g.,\ without the High layer compatibility information element) if a
call is routed from an existing network which does not support High layer
compatibility information element transfer.
.PP
In cases where the network cannot provide all incoming call
information, or where the network is not aware of the existence or absence
of some service information (such as compatibility information), the incoming
SETUP message includes a Progress indicator information element, containing
progress indicator No.\ 1, \fICall is not end\(hyto\(hyend ISDN, further
call progress\fR \fIinformation may be available in\(hyband\fR , or No.\
3, \fIOrigination address is\fR
\fInon\(hyISDN\fR (see Annex\ I).
.PP
The terminal equipment receiving a SETUP with a progress indicator
information element shall modify its compatibility checking, the terminal
equipment should regard the compatibility as successful if it is compatible
with the included information, which as a minimum, will be the bearer
capability information element. A terminal equipment expecting information
in addition to the Bearer capability information element in a full ISDN
environment need not reject the call if such information is absent but a
Progress indicator information element is included.
.RT
.ce 1000
ANNEX\ C
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBTransit network selection\fR
.sp 1P
.RT
.ce 0
.PP
\fR
This Annex describes the processing of the transit network selection information
element.
.sp 1P
.RT
.sp 1P
.LP
C.1
\fISelection not supported\fR
.sp 9p
.RT
.PP
Some networks may not support transit network selection. In this
case, when a Transit network selection information element is received, that
information element is processed according to the rules for unimplemented
non\(hymandatory information elements (see \(sc\ 5.8.7.1).
.RT
.sp 1P
.LP
C.2
\fISelection supported\fR
.sp 9p
.RT
.PP
When transit network selection is supported, the user identifies
the selected transit network(s) in the SETUP message. One Transit network
selection information element is used to convey a single network
identification.
.PP
The user may specify more than one transit network. Each
identification is placed in a separate information element. The call would
then be routed through the specified transit networks in the order listed
in the
SETUP. For example, a user lists networks\ A and\ B, in that order, in two
Transit network selection information elements within a SETUP message.
The call is first routed to network\ A (either directly or indirectly),
and then to
network\ B (either directly or indirectly), before being delivered.
.PP
As the call is delivered to each selected network, the
corresponding transit selection may be stripped from the call establishment
signalling, in accordance with the relevant internetwork signalling
arrangement. The Transit network selection information element(s) is/are not
delivered to the destination user.
.PP
No more than four Transit network selection information elements
may be used in a single SETUP message.
.PP
When a network cannot route the call because the route is busy, the
network shall initiate call clearing in accordance with \(sc\ 5.3 with cause
No.\ 34, \fIno circuit/channel available\fR .
.PP
If a network does not recognize the specified transit network, the
network shall initiate call clearing in accordance with \(sc\ 5.3, with cause
No.\ 2, \fIno route to specified transit network\fR . The diagnostic field
shall
contain a copy of the contents of the Transit network selection information
element identifying the unreachable network.
.bp
.PP
A network may screen all remaining transit network selection
information elements to:
.RT
.LP
a)
avoid routing loops; or
.LP
b)
ensure an appropriate business relationship exists between
selected networks; or
.LP
c)
ensure compliance with national and local regulations.
.PP
If the transit network selection is of an incorrect format, or
fails to meet criteria\ a), b) or\ c), the network shall initiate call
clearing in accordance with \(sc\ 5.3, with cause No.\ 91, \fIinvalid transit
network\fR
\fIselection\fR .
.PP
When a user includes the Transit network selection information
element, pre\(hysubscribed default Transit network selection information
(if any) is overridden.
.RT
.ce 1000
ANNEX\ D
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBExtensions for symmetric call operation\fR
.sp 1P
.RT
.ce 0
.LP
D.1
\fIAdditional message handling\fR
.sp 1P
.RT
.PP
In symmetric applications, the SETUP message will contain a Channel Identification
information element indicating a particular B\(hychannel to be
used for the call. A point\(hyto\(hypoint data link shall be used to carry
the SETUP message.
.PP
The procedure described in \(sc\ 5 for the user side should normally
be followed. Where additional procedures are required, they are detailed
below.
.RT
.sp 1P
.LP
D.1.1
\fIB\(hychannel selection \(em symmetric interface\fR
.sp 9p
.RT
.PP
Only B\(hychannels controlled by the same D\(hychannel will be the
subject of the selection procedure. The selection procedure is as
follows:
.RT
.LP
a)
The SETUP message will indicate one of the following:
.LP
1)
channel is indicated, no acceptable alternative, or
.LP
2)
channel is indicated, any alternative is acceptable.
.LP
b)
In cases 1) and 2), if the indicated channel is acceptable
and available, the recipient of the SETUP message reserves it
for the call. In case\ 2), if the recipient of the SETUP message
cannot grant the indicated channel, it reserves any other
available B\(hychannel associated with the D\(hychannel.
.LP
c)
If the SETUP message included all information required to
establish the call, the recipient of SETUP message indicates the
selected B\(hychannel in a CALL PROCEEDING message transferred
across the interface and enters the Incoming Call Proceeding
state.
.LP
d)
If the SETUP message did not include all the information
required to establish the call, B\(hychannel is indicated in a
SETUP ACKNOWLEDGE message sent across the interface. The
additional call establishment information, if any, is sent in
one or more INFORMATION messages transferred across the
interface in the same direction as the SETUP message. When
all call establishment information is received, a CALL
PROCEEDING, ALERTING, or CONNECT message, as appropriate, is
transferred across the interface.
.LP
e)
In case 1) if the indicated B\(hychannel is not available, or
in case\ 2) if no B\(hychannel is available, a RELEASE COMPLETE
message with a cause value of No.\ 44, \fIrequested\fR \fIcircuit/channel
not available\fR , or No.\ 34, \fIno circuit/channel\fR
\fIavailable\fR , respectively is returned to the initiator of the
call. The sender of this message remains in the Null state.
.LP
f
)
If the channel indicated in the CALL PROCEEDING or SETUP
ACKNOWLEDGE message is unacceptable to the initiator of the
call, it clears the call in accordance with \(sc\ 5.3.
.sp 1P
.LP
D.1.2
\fICall confirmation\fR
.sp 9p
.RT
.PP
Upon receipt of a SETUP message, the equipment enters the Call
Present state. Valid responses to the SETUP message are a SETUP ACKNOWLEDGE,
an ALERTING, a CALL PROCEEDING, a CONNECT, or a RELEASE COMPLETE message.
.PP
If the indicated channel is acceptable to the initiator of the
call, the initiator shall attach to the indicated B\(hychannel.
.bp
.RT
.sp 1P
.LP
D.1.3
\fIClearing by the called user employing user\(hyprovided\fR
\fItones/announcements\fR
.sp 9p
.RT
.PP
In addition to the procedures described in \(sc 5.3.3, if the bearer capability
is either audio or speech, the called user or private network may
apply in\(hyband tones/announcements in the clearing phase. When in\(hyband
tones/announcements are provided, the DISCONNECT message contains progress
indicator No.\ 8, \fIin\(hyband information or appropriate pattern is now\fR
\fIavailable\fR , and the called user or private network proceeds similarly as
stipulated in \(sc\ 5.3.4.1 for the network.
.RT
.sp 1P
.LP
D.1.4
\fIActive indication\fR
.sp 9p
.RT
.PP
Upon receipt of a CONNECT message, the initiator of the call shall respond
with a CONNECT ACKNOWLEDGE message and enter the Active state.
.RT
.sp 1P
.LP
D.2
\fITimers for call establishment\fR
.sp 9p
.RT
.PP
User end points implement the network side timers T301, T303 and
T310 along with the corresponding network side procedures for actions taken
upon expiration of these timers. See Table\ 9\(hy2/Q.931 for the call
establishment user\(hyside timers and procedures.
.RT
.sp 1P
.LP
D.3
\fICall collisions\fR
.sp 9p
.RT
.PP
In symmetric arrangements, call collisions can occur when both
sides simultaneously transfer a SETUP message indicating the same channel.
In the absence of administrative procedures for assignment of channels
to each
side of the interface, the following procedure is employed.
.PP
First, one side of the interface will be designated the \fInetwork\fR | nd
the other side of the interface will be designated the \fIuser\fR . Second,
for the three possible scenarios where the same channel is indicated by
combinations of preferred and exclusive from the user and network sides,
the following
procedure is used:
.RT
.LP
a)
\fInetwork preferred, user preferred\fR :
.LP
the network preferred channel is awarded and an alternate
channel is indicated in the first response to the user SETUP
message;
.LP
b)
\fInetwork exclusive, user exclusive\fR :
.LP
the network exclusive channel is awarded and the user
SETUP message is cleared with a RELEASE COMPLETE message with
cause No.\ 34, \fIno circuit/channel available\fR ;
.LP
c)
\fInetwork preferred, user exclusive; or network\fR \fIexclusive, user
preferred\fR :
.LP
the side of the interface with an exclusive indicator in a
SETUP message is awarded the channel and an alternate channel is
indicated in the first response to the side using a preferred
indicator in the SETUP message.
.PP
Channel identification is allowed in both directions for ALERTING and CONNECT.
.ce 1000
ANNEX\ E
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBNetwork specific facility selection\fR
.sp 1P
.RT
.ce 0
.PP
This Annex describes the processing of the Network\(hyspecific
facilities information element. The purpose of this information element
is to indicate which network facilities are being invoked.
.sp 1P
.RT
.sp 1P
.LP
E.1
\fIDefault provider\fR
.sp 9p
.RT
.PP
When the length of the network identification field is set to zero in the
Network\(hyspecific facilities information element, then the services
identified in this information element are to be provided by the network
side of the interface receiving the information element (default provider).
If the Network\(hyspecific facilities information element is recognized
but the network facilities are not understood, then this information element
is processed
according to rules for non\(hymandatory information element content error (see
\(sc\ 5.8.7.1).
.bp
.RT
.sp 1P
.LP
E.2
\fIRouting not supported\fR
.sp 9p
.RT
.PP
Some networks may not support the routing to the remote network of the
contents of the Network\(hyspecific facilities information element. In
this
case, when a Network\(hyspecific facilities information element is received,
that information element is processed according to the rules for unimplemented
non\(hymandatory information elements (see \(sc\ 5.8.7.1).
.RT
.sp 1P
.LP
E.3
\fIRouting supported\fR
.sp 9p
.RT
.PP
When Network\(hyspecific facility information element routing is
supported, the user identifies the network provider in this information
element in the Q.931 SETUP message. One Network\(hyspecific facility information
element is used to identify a network provider.
.PP
The user may specify more than one network provider by repeating
the Network\(hyspecific facilities information element. Each identification is
placed in a separate information element. The information is routed to the
indicated network provider as long as the call is also handled by the network
provider (see Annex\ C, Transit network selection). For example, if the
user
lists network providers\ A and\ B in separate Network\(hyspecific facilities
information elements in a call control message, there must be corresponding
Transit network selection information elements in the SETUP message identifying
those networks (or default call routing via\ A and\ B that was established
prior to call establishment).
.PP
As the signalling messages containing Network\(hyspecific facilities
information elements are delivered to the indicated remote network, they
may be stripped from the signalling messages, in accordance with the relevant
internetworking signalling arrangement. The Network\(hyspecific facilities
information elements may be delivered to the identified user.
.PP
No more than four Network\(hyspecific facilities information elements may
be used in a SETUP message. When the information element is repeated, the
order of presentation of the elements in a message is not significant.
Further, there does not have to be a one\(hyto\(hyone correspondence between
Network\(hyspecific
facilities information elements and Transit network selection information
elements.
.PP
If a network cannot pass the information to the indicated network
provider, either due to:
.RT
.LP
\(em
the network indicated is not part of the call path, or
.LP
\(em
no mechanism exists for passing the information to
identified network,
.LP
the network shall initiate call clearing in accordance with \(sc 5.3,
with cause No.\ 2, \fIno route to specified transit network\fR . The diagnostic
field may optionally contain a copy of the first 5\ octets of the
network\(hyspecific facilities information element.
.PP
When the user includes the Network\(hyspecific facilities information element
in the SETUP message, pre\(hysubscribed default service treatment (if any)
is overridden.
.ce 1000
ANNEX\ F
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBD\(hychannel backup procedures\fR
.sp 1P
.RT
.ce 0
.LP
F.0
\fIForeword\fR
.sp 1P
.RT
.PP
The procedure defined in this Annex can be used when
non\(hyassociated signalling is applied to multiple primary rate access
arrangements. This feature can be provided on a subscription basis and is
network dependent.
.RT
.sp 1P
.LP
F.1
\fIGeneral\fR
.sp 9p
.RT
.PP
In associated signalling, the D\(hychannel signalling entity can only assign
calls to channels on the interface containing the D\(hychannel. When the
D\(hychannel signalling entity can assign calls to channels on more than one
interface (including the one containing the D\(hychannel), this is called
non\(hyassociated signalling. Figure\ F\(hy1/Q.931 is an example of associated
signalling used on each of the three interfaces between a user (e.g.,\
a PABX) and a network. Replacing associated signalling with non\(hyassociated
signalling on these interfaces results in the example shown in Figure\
F\(hy2/Q.931.
.bp
.PP
When non\(hyassociated signalling is employed, the reliability of the
signalling performance for the ISDN interfaces controlled by the D\(hychannel
may be unacceptable. To improve the reliability, a D\(hychannel backup
procedure
employing a standby D\(hychannel is necessary. The next section describes the
backup procedure which is optional for end\(hypoints that use non\(hyassociated
signalling.
.RT
.LP
.rs
.sp 11P
.ad r
\fBFigure F\(hy1/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 13P
.ad r
\fBFigure F\(hy2/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.sp 2P
.LP
F.2
\fID\(hychannel backup procedure\fR
.sp 1P
.RT
.sp 1P
.LP
F.2.1
\fIRole of each D\(hychannel\fR
.sp 9p
.RT
.PP
When two or more interfaces connect a network and a user, a primary D\(hychannel
(labelled \*Qone\*U) is always present on one interface. On a different
interface, a secondary D\(hychannel (labelled \*Qtwo\*U) is present that
can also send signalling packets. Figure\ F\(hy3/Q.931 shows the addition
of a secondary
(i.e.,\ backup) D\(hychannel to the arrangement shown in Figure\ F\(hy2/Q.931.
.PP
D\(hychannel one is used to send signalling packets across the
user\(hynetwork interface for multiple interfaces including the interface
containing D\(hychannel two. D\(hychannel two is in a standby role and
is active at layer\ 2 only. All SAPI groups (e.g.,\ 0, 16 and\ 63) are
alive and can send
packets. At periodic intervals determined by the appropriate layer\ 2 timer
associated with SAPI\ 0, a link audit frame will be sent on the point\(hyto\(hypoint
signalling link with DLCI\ =\ 0 of D\(hychannel two.
.RT
.PP
Since D\(hychannel two is in a standby role, load sharing between
D\(hychannels one and two is not possible. Furthermore, D\(hychannel two
can not
serve as a B\(hychannel when it is in a standby role. Lastly, D\(hychannel
two can
only back up the signalling functions provided by D\(hychannel one and not some
other D\(hychannel on a different interface.
.bp
.LP
.rs
.sp 14P
.ad r
\fBFigure F\(hy3/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
F.2.2
\fISwitchover of D\(hychannels\fR
.sp 9p
.RT
.PP
Failure of D\(hychannel one is determined by the receipt of a
DL
\(ulRELEASE
\(ulINDICATION primitive from the data link layer. At this point,
optionally additional attempts to re\(hyestablish this D\(hychannel may
be initiated. Otherwise, it is assumed that D\(hychannel one has failed.
.PP
Two states are defined for any D\(hychannel in a backup arrangement. A
D\(hychannel is termed out\(hyof\(hyservice when layer\ 2 remains in the
TEI\(hyassigned
state, after being periodically requested by layer\ 3 to establish
multiple\(hyframe
operation. A D\(hychannel is termed maintenance busy when layer\ 2 is held
in the TEI\(hyassigned state by layer\ 3. While in the maintenance busy
condition, the
response to an invitation for link establishment is met with the transmission
of a DM (Disconnected Mode).
.PP
When the D\(hychannel one has failed and if D\(hychannel two is not in an
out\(hyof\(hyservice condition, the layer\ 3 shall place D\(hychannel one in a
maintenance busy condition, start timer\ T321 and then issue a
DL
\(ulESTABLISH
\(ulREQUEST primitive to re\(hyinitialize SAPI\ 0 link\ 0 of D\(hychannel two.
Upon receipt of this primitive, the data link layer issues an SABME command.
Timer\ T200 is started. The end receiving the SABME command on D\(hychannel two
follows the remainder of the Q.931 procedures for establishing logical link
with DLCI\ =\ 0.
.PP
Once the logical link with DLCI\ =\ 0 in D\(hychannel two is in the Link
Established state, the procedure to establish layer\ 3 call control signalling
can begin on the link.
.PP
To establish the backup D\(hychannel for carrying call control
signalling, layer\ 3 should issue an appropriate layer\ 3 message (e.g.,\
a STATUS ENQUIRY on stable call reference numbers). Once a response to
that layer\ 3
message is received, D\(hychannel two is declared to be the active D\(hychannel,
normal layer\ 3 call control signalling may proceed, timer\ T321 is stopped,
and D\(hychannel one is moved to the out\(hyof\(hyservice condition. If
the maintenance busy timer\ T321 expires before a response is received
to the layer\ 3 message,
D\(hychannel one is moved to the out\(hyof\(hyservice condition and an
attempt is made to establish the logical link with DLCI\ =\ 0 on D\(hychannel
one and D\(hychannel
two.
.PP
If the logical link with DLCI\ =\ 0 of both D\(hychannel one and D\(hychannel
two are initialized simultaneously, the designated primary shall be chosen
as the D\(hychannel for carrying call control signalling. The designated
primary
D\(hychannel is agreed upon at subscription time by both sides of the interface.
.PP
After a switchover, old D\(hychannel two becomes the new D\(hychannel one
and old D\(hychannel one becomes the new D\(hychannel two.
.PP
Upon completion of appropriate maintenance activity to D\(hychannel
two, the logical links for SAPI\ =\ 0 and\ 63 are made active at layer\
2 and the D\(hychannel is removed from the out\(hyof\(hyservice condition.
.PP
D\(hychannels may only be switched again by a failure of D\(hychannel one
or a routing or maintenance request from a peer entity.
.bp
.RT
.ce 1000
ANNEX\ G
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBCause definitions\fR
.sp 1P
.RT
.ce 0
.PP
This Annex provides definitions to the causes in \(sc 4.5.12. A Table is
provided in Appendix\ I to indicate how these causes are used in the call
control procedures.
.sp 1P
.RT
.sp 2P
.LP
G.1
\fINormal class\fR
.sp 1P
.RT
.sp 1P
.LP
G.1.1
\fICause No. 1: unallocated (unassigned) number\fR
.sp 9p
.RT
.PP
This cause indicates that the destination requested by the calling user
cannot be reached because, although the number is in a valid format, it
is not currently assigned (allocated).
.RT
.sp 1P
.LP
G.1.2
\fICause No. 2: no route to specified transit network\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause has
received a request to route the call through a particular transit network
which it does not recognize. The equipment sending this cause does not
recognize the transit network either because the transit network does not
exist or
because that particular network, while it does exist, does not serve the
equipment which is sending this cause.
.PP
This cause is supported on a network\(hydependent basis.
.RT
.sp 1P
.LP
G.1.3
\fICause No. 3: no route to destination\fR
.sp 9p
.RT
.PP
This cause indicates that the called user cannot be reached because the
network through which the call has been routed does not serve the
destination desired.
.PP
This cause is supported on a network\(hydependent basis.
.RT
.sp 1P
.LP
G.1.4
\fICause No. 6: channel unacceptable\fR
.sp 9p
.RT
.PP
This cause indicates the channel most recently identified is not
acceptable to the sending entity for use in this call.
.RT
.sp 1P
.LP
G.1.5
\fICause No. 7: call awarded and being delivered in an established\fR
\fIchannel\fR
.sp 9p
.RT
.PP
This cause indicates that the user has been awarded the incoming
call, and that the incoming call is being connected to a channel already
established to that user for similar calls (e.g.,\ packet\(hymode X.25 virtual
calls).
.RT
.sp 1P
.LP
G.1.6
\fICause No. 16: normal call clearing\fR
.sp 9p
.RT
.PP
This cause indicates that the call is being cleared because one of the
users involved in the call has requested that the call be cleared.
.PP
Under normal situations, the source of this cause is not the
network.
.RT
.sp 1P
.LP
G.1.7
\fICause No. 17: user busy\fR
.sp 9p
.RT
.PP
This cause is used when the called user has indicated the inability to
accept another call.
.PP
It is noted that the user equipment is compatible with the call.
.RT
.sp 1P
.LP
G.1.8
\fICause No. 18: no user responding\fR
.sp 9p
.RT
.PP
This cause is used when a user does not respond to a call
establishment message with either an alerting or connect indication within
the prescribed period of time allocated (defined in Recommendation\ Q.931
by the
expiry of either timer\ T303 or\ T310).
.bp
.RT
.sp 1P
.LP
G.1.9
\fICause No. 19: no answer from user (user alerted)\fR
.sp 9p
.RT
.PP
This cause is used when a user has provided an alerting indication but
has not provided a connect indication within a prescribed period of time.
.PP
\fINote\fR \ \(em\ This cause is not necessarily generated by Q.931 procedures
but may be generated by internal network timers.
.RT
.sp 1P
.LP
G.1.10\ \ \fICause No. 21: call rejected\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause does not wish
to accept this call, although it could have accepted the call because the
equipment sending this cause is neither busy nor incompatible.
.RT
.sp 1P
.LP
G.1.11\ \ \fICause No. 22: number changed\fR
.sp 9p
.RT
.PP
This cause is returned to a calling user when the called party
number indicated by the calling user is no longer assigned. The new called
party number may optionally be included in the diagnostic field. If a network
does not support this capability, cause No.\ 1, \fIunassigned (unallocated)\fR
\fInumber\fR shall be used.
.RT
.sp 1P
.LP
G.1.12\ \ \fICause No. 26: non\(hyselected user clearing\fR
.sp 9p
.RT
.PP
This cause indicates that the user has not been awarded the
incoming call.
.RT
.sp 1P
.LP
G.1.13\ \ \fICause No. 27: destination out of order\fR
.sp 9p
.RT
.PP
This cause indicates that the destination indicated by the user
cannot be reached because the interface to the destination is not functioning
correctly. The term \*Qnot functioning correctly\*U indicates that a signalling
message was unable to be delivered to the remote user; e.g.,\ a physical
layer or data link layer failure at the remote user, user equipment
off\(hyline,\ etc.
.RT
.sp 1P
.LP
G.1.14\ \ \fICause No. 28: invalid number format (address incomplete)\fR
.sp 9p
.RT
.PP
This cause indicates that the called user cannot be reached because the
called party number is not a valid format or is not complete.
.RT
.sp 1P
.LP
G.1.15\ \ \fICause No. 29: facility rejected\fR
.sp 9p
.RT
.PP
This cause is returned when a facility requested by the user can
not be provided by the network.
.RT
.sp 1P
.LP
G.1.16\ \ \fICause No. 30: response to STATUS ENQUIRY\fR
.sp 9p
.RT
.PP
This cause is included in the STATUS message when the reason for
generating the STATUS message was the prior receipt of a STATUS ENQUIRY
message.
.RT
.sp 1P
.LP
G.1.17\ \ \fICause No. 31: normal, unspecified\fR
.sp 9p
.RT
.PP
This cause is used to report a normal event only when no other
cause in the normal class applies.
.RT
.sp 2P
.LP
G.2
\fIResource unavailable class\fR
.sp 1P
.RT
.sp 1P
.LP
G.2.1
\fICause No. 34: no circuit/channel available\fR
.sp 9p
.RT
.PP
This cause indicates that there is no appropriate circuit/channel presently
available to handle the call.
.RT
.sp 1P
.LP
G.2.2
\fICause No. 38: network out of order\fR
.sp 9p
.RT
.PP
This cause indicates that the network is not functioning correctly and
that the condition is likely to last a relatively long period of time;
e.g.,\ immediately re\(hyattempting the call is not likely to be successful.
.bp
.RT
.sp 1P
.LP
G.2.3
\fICause No. 41: temporary failure\fR
.sp 9p
.RT
.PP
This cause indicates that the network is not functioning correctly and
that the condition is not likely to last a long period of time; e.g.,\
the user may wish to try another call attempt almost immediately.
.RT
.sp 1P
.LP
G.2.4
\fICause No. 42: switching equipment congestion\fR
.sp 9p
.RT
.PP
This cause indicates that the switching equipment generating this cause
is experiencing a period of high traffic.
.RT
.sp 1P
.LP
G.2.5
\fICause No. 43: access information discarded\fR
.sp 9p
.RT
.PP
This cause indicates that the network could not deliver access
information to the remote user as requested: i.e.,\ a user\(hyto\(hyuser
information, low layer compatibility, high layer compatibility, or sub\(hyaddress
as indicated in the diagnostic.
.PP
It is noted that the particular type of access information discarded is
optionally included in the diagnostic.
.RT
.sp 1P
.LP
G.2.6
\fICause No. 44: requested circuit/channel not available\fR
.sp 9p
.RT
.PP
This cause is returned when the circuit or channel indicated by the requesting
entity can not be provided by the other side of the interface.
.RT
.sp 1P
.LP
G.2.7
\fICause No. 47: resource unavailable, unspecified\fR
.sp 9p
.RT
.PP
This cause is used to report a resource unavailable event only when no
other cause in the resource unavailable class applies.
.RT
.sp 2P
.LP
G.3
\fIService or option not available class\fR
.sp 1P
.RT
.sp 1P
.LP
G.3.1
\fICause No. 49: Quality of Service not available\fR
.sp 9p
.RT
.PP
This cause is used to report that the requested Quality of Service, as
defined in Recommendation\ X.213, cannot be provided (e.g.,\ throughput
or
transit delay cannot be supported).
.RT
.sp 1P
.LP
G.3.2
\fICause No. 50: requested facility not subscribed\fR
.sp 9p
.RT
.PP
This cause indicates that the requested supplementary service could not
be provided by the network because the user has not completed the necessary
administrative arrangements with its supporting networks.
.RT
.sp 1P
.LP
G.3.3
\fICause No. 57: bearer capability not authorized\fR
.sp 9p
.RT
.PP
This cause indicates that the user has requested a bearer
capability which is implemented by the equipment which generated this cause
but the user is not authorized to use.
.RT
.sp 1P
.LP
G.3.4
\fICause No. 58: bearer capability not presently available\fR
.sp 9p
.RT
.PP
This cause indicates that the user has requested a bearer
capability which is implemented by the equipment which generated this cause
but which is not available at this time.
.RT
.sp 1P
.LP
G.3.5
\fICause No. 63: service or option not available, unspecified\fR
.sp 9p
.RT
.PP
This cause is used to report a service or option not available
event only when no other cause in the service or option not available class
applies.
.RT
.sp 2P
.LP
G.4
\fIService or option not implemented class\fR
.sp 1P
.RT
.sp 1P
.LP
G.4.1
\fICause No. 65: bearer capability not implemented\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause does not support
the bearer capability requested.
.bp
.RT
.sp 1P
.LP
G.4.2
\fICause No. 66: channel type not implemented\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause does not support
the channel type requested.
.RT
.sp 1P
.LP
G.4.3
\fICause No. 69: requested facility not implemented\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause does not support
the requested supplementary service.
.RT
.sp 1P
.LP
G.4.4
\fICause No. 70: only restricted digital information bearer\fR
\fIcapability is available\fR
.sp 9p
.RT
.PP
This cause indicates that one equipment has requested an
unrestricted bearer service but that the equipment sending this cause only
supports the restricted version of the requested bearer capability.
.RT
.sp 1P
.LP
G.4.5
\fICause No. 79: service or option not implemented, unspecified\fR
.sp 9p
.RT
.PP
This cause is used to report a service or option not implemented
event only when no other cause in the service or option not implemented
class applies.
.RT
.sp 2P
.LP
G.5
\fIInvalid message (e.g., parameter out of range) class\fR
.sp 1P
.RT
.sp 1P
.LP
G.5.1
\fICause No. 81: invalid call reference value\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause has
received a message with a call reference which is not currently in use
on the user\(hynetwork interface.
.RT
.sp 1P
.LP
G.5.2
\fICause No. 82: identified channel does not exist\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause has
received a request to use a channel not activated on the interface for
a call. For example, if a user has subscribed to those channels on a primary
rate
interface numbered from\ 1 to\ 12 and the user equipment or the network
attempts to use channels\ 13 through\ 23, this cause is generated.
.RT
.sp 1P
.LP
G.5.3
\fICause No. 83: a suspended call exists, but this call identity\fR
\fIdoes not\fR
.sp 9p
.RT
.PP
This cause indicates that a call resume has been attempted with a call
identity which differs from that in use for any presently suspended
call(s).
.RT
.sp 1P
.LP
G.5.4
\fICause No. 84: call identity in use\fR
.sp 9p
.RT
.PP
This cause indicates that the network has received a call suspended request.
The call suspend request contained a call identity (including the null
call identity) which is already in use for a suspended call within the
domain of interfaces over which the call might be resumed.
.RT
.sp 1P
.LP
G.5.5
\fICause No. 85: no call suspended\fR
.sp 9p
.RT
.PP
This cause indicates that the network has received a call resume
request. The call resume request contained a Call identity information
element which presently does not indicate any suspended call within the
domain of
interfaces over which calls may be resumed.
.RT
.sp 1P
.LP
G.5.6
\fICause No. 86: call having the requested call identity has been\fR
\fIcleared\fR
.sp 9p
.RT
.PP
This cause indicates that the network has received a call resume
request. The call resume request contained a Call identity information
element which once indicated a suspended call; however, that suspended
call was cleared while suspended (either by network timeout or by remote
user).
.RT
.sp 1P
.LP
G.5.7
\fICause No. 88: incompatible destination\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause has
received a request to establish a call which has low layer compatibility,
high layer compatibility, or other compatibility attributes (e.g.,\ data
rate) which cannot be accommodated.
.bp
.RT
.sp 1P
.LP
G.5.8
\fICause No. 91: invalid transit network selection\fR
.sp 9p
.RT
.PP
This cause indicates that a transit network identification was
received which is of an incorrect format as defined in Annex\ C/Q.931.
.RT
.sp 1P
.LP
G.5.9
\fICause No. 95: invalid message, unspecified\fR
.sp 9p
.RT
.PP
This cause is used to report an invalid message event only when no other
cause in the invalid message class applies.
.RT
.sp 2P
.LP
G.6
\fIProtocol error (e.g., unknown message) class\fR
.sp 1P
.RT
.sp 1P
.LP
G.6.1
\fICause No. 96: mandatory information element is missing\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause has
received a message which is missing an information element which must be
present in the message before that message can be processed.
.RT
.sp 1P
.LP
G.6.2
\fICause No. 97: message type non\(hyexistent or not implemented\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause has
received a message with a message type it does not recognize either because
this is a message
not defined or defined but not implemented by the equipment sending this
cause.
.RT
.sp 1P
.LP
G.6.3
\fICause No. 98: message not compatible with call state or message\fR
\fItype non\(hyexistent or not implemented\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause has
received a message such that the procedures do not indicate that this is a
permissible message to receive while in the call state, or a STATUS message
was received indicating an incompatible call state.
.RT
.sp 1P
.LP
G.6.4
\fICause No. 99: information element non\(hyexistent or not\fR
\fIimplemented\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause has
received a message which includes information elements not recognized because
the information element identifier is not defined or it is defined but
not
implemented by the equipment sending the cause. However, the information
element is not required to be present in the message in order for the equipment
sending the cause to process the message.
.RT
.sp 1P
.LP
G.6.5
\fICause No. 100: invalid information element contents\fR
.sp 9p
.RT
.PP
This cause indicates that the equipment sending this cause has
received an information element which it has implemented; however, one
or more of the fields in the information element are coded in such a way
which has not been implemented by the equipment sending this cause.
.RT
.sp 1P
.LP
G.6.6
\fICause No. 101: message not compatible with call state\fR
.sp 9p
.RT
.PP
This cause indicates that a message has been received which is
incompatible with the call state.
.RT
.sp 1P
.LP
G.6.7
\fICause No. 102: recovery on timer expiry\fR
.sp 9p
.RT
.PP
This cause indicates that a procedure has been initiated by the
expiry of a timer in association with Q.931 error handling procedures.
.RT
.sp 1P
.LP
G.6.8
\fICause No. 111: protocol error, unspecified\fR
.sp 9p
.RT
.PP
This cause is used to report a protocol error event only when no
other cause in the protocol error class applies.
.RT
.sp 2P
.LP
G.7
\fIInterworking class\fR
.sp 1P
.RT
.sp 1P
.LP
G.7.1
\fICause No. 127: interworking, unspecified\fR
.sp 9p
.RT
.PP
This cause indicates that there has been interworking with a
network which does not provide causes for actions it takes, thus, the precise
cause for a message which is being sent cannot be ascertained.
.bp
.RT
.ce 1000
ANNEX\ H
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBExamples of information elements coding\fR
.sp 1P
.RT
.ce 0
.PP
This Annex gives examples on the detailed coding of the
following information elements:
.sp 1P
.RT
.LP
\(em
bearer capability information element;
.LP
\(em
channel identification information element;
.LP
\(em
called/calling party sub\(hyaddress.
.sp 2P
.LP
H.1
\fIBearer capability information element\fR
.sp 1P
.RT
.sp 1P
.LP
H.1.1
\fICoding for speech\fR
.sp 9p
.RT
.ce
\fBH.T. [T180.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Bearer Capability
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 1 0 0 Octet 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.TE
.TS
center box ;
lw(144p) .
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 1 1 Octet 2
.TE
.TS
center box ;
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
0
0
CCITT
0
0
0
0
0
Speech
} Octet 3
.TE
.TS
center box ;
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
0
0
Circuit mode
1
0
0
0
0
64 kbit/s
} Octet 4
.TE
.TS
center box ;
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
0
1
Layer 1
0
0
0
1
0
G.711 [10] \(*m\(hylaw
or
} Octet 5
.T&
lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , l s s s s.
.TE
.nr PS 9
.RT
.ad r
\fBTableau [T180.931], p. 7\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 12P
.ad r
BLANC
.ad b
.RT
.LP
.bp
.sp 1P
.LP
H.1.2
\fICoding for 3.1 kHz audio\fR
.sp 9p
.RT
.ce
\fBH.T. [T181.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Bearer capability
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 1 0 0 Octet 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 1 1 Octet 2
.TE
.TS
center box ;
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
0
0
CCITT
1
0
0
0
0
3.1 kHz Audio
} Octet 3
.T&
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
0
0
Circuit mode
1
0
0
0
0
64 kbit/s
} Octet 4
.T&
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
0
1
Layer 1
0
0
0
1
0
G.711 [10] \(*m\(hylaw
or
} Octet 5
.T&
lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , l s s s s.
.TE
.nr PS 9
.RT
.ad r
\fBTable [T181.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.sp 2P
.LP
.sp 3
H.1.3
\fICoding for unrestricted digital information\fR
.sp 1P
.RT
.sp 1P
.LP
\fIType 1:\fR Synchronous 64 kbit/s working
.sp 9p
.RT
.ce
\fBH.T. [T182.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box ;
c.
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Bearer capability
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 1 0 0 Octet 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 1 0 Octet 2
.TE
.TS
center box ;
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
0
0
CCITT
0
1
0
0
0
Unrestricted digital information
} Octet 3
.T&
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext
0
0
Circuit mode
1
0
0
0
0
64 kbit/s
} Octet 4
.TE
.nr PS 9
.RT
.ad r
\fBTable [T182.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 1P
.LP
\fIType 2:\fR Synchronous rates less than 64 kbit/s with CCITT
standardized rate adaption V.110\ [7]/X.30 | 8]; in\(hyband negotiation not
possible.
.sp 9p
.RT
.ce
\fBH.T. [T183.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Bearer capability
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 1 0 0 Octet 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 1 0 0 Octet 2
.TE
.TS
center box ;
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
0
0
CCITT
0
1
0
0
0
Unrestricted digital information
} Octet 3
.T&
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
0
0
Circuit mode
1
0
0
0
0
64 kbit/s
} Octet 4
.T&
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
0
Ext.
0
1
layer 1
0
0
0
0
1
Rate adaptation
} Octet 5
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(90p) | lw(24p) .
1 Ext. 0 Synch. 0 Negot. User rate Octet 5a
.TE
.nr PS 9
.RT
.ad r
\fBTable [T183.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
H.1.4
\fICoding for case B X.31 packet mode access connections\fR
.sp 9p
.RT
.ce
\fBH.T. [T184.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Bearer capability
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 1 0 0 Octet 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 1 0 0 Octet 2
.TE
.TS
center box ;
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
0
0
CCITT
0
1
0
0
0
Unrestricted digital information
} Octet 3
.T&
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
1
0
Packet mode
0
0
0
0
0
.
} Octet 4
.T&
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
1
0
Layer 2
0
0
1
1
0
X.25 [5] link level
} Octet 6
.T&
cw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(18p) | lw(24p) , ^ | l s | l s s s.
{
1
Ext.
1
1
Layer 3
0
0
1
1
0
X.25 packet layer
} Octet 7
.TE
.nr PS 9
.RT
.ad r
\fBTable [T184.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 2P
.LP
H.2
\fIChannel identification information element\fR
.sp 1P
.RT
.sp 1P
.LP
H.2.1
\fIBasic interface, circuit mode, B\(hychannel\fR
.sp 9p
.RT
.sp 1P
.LP
\fIExample a)\fR
.sp 9p
.RT
.ce
\fBH.T. [T185.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Channel identification
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 1 1 0 0 0 Octets 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 0 1 Octets 2
.TE
.TS
center box ;
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 0 0 0 0 0 1 Octets 3
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(36p) | lw(24p) .
Ext. Int. id. present Int. type Spare Pref./ Excl. D\(hych. id. Ch. sel.
.TE
.nr PS 9
.RT
.ad r
\fBTable [T185.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.sp 1
\(em
Channel B1 preferred.
.LP
\(em
Channel is located in same interface which includes the
D\(hychannel.
.sp 1P
.LP
\fIExample b)\fR
.sp 9p
.RT
.ce
\fBH.T. [T186.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Channel identification
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 1 1 0 0 0 Octets 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 0 1 Octets 2
.T&
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 0 0 0 0 1 1 Octets 3
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(36p) | lw(24p) .
Ext. Int. id. present Int. type Spare Pref./ Excl. D\(hych. id. Ch. sel.
.TE
.nr PS 9
.RT
.ad r
\fBTable [T186.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.sp 1
\(em
Any B\(hychannel.
.bp
.sp 2P
.LP
H.2.2
\fIPrimary rate interface, circuit mode, B\(hychannel\fR
.sp 1P
.RT
.sp 1P
.LP
\fIExample a)\fR
.sp 9p
.RT
.ce
\fBH.T. [T187.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Channel identification
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 1 1 0 0 0 Octets 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 1 1 Octets 2
.TE
.TS
center box ;
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 1 0 0 0 0 1 Octets 3
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(36p) | lw(24p) .
Ext. Int. id. present Int. type Spare Pref./ Excl. D\(hych. id. Ch. sel.
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 0 0 0 0 1 1 Octets 3.2
.T&
lw(18p) | cw(36p) | cw(18p) | cw(72p) | lw(24p) .
Coding standard No./Map Ch. type/Map type
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 0 1 Octets 3.3
.T&
cw(144p) | lw(24p) .
Ch. number/Slot map
.TE
.nr PS 9
.RT
.ad r
\fBTable [T187.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
\(em
The channel is a B\(hychannel.
.LP
\(em
The indicated channel is preferred.
.LP
\(em
The channel is located in the same interface which includes
the D\(hychannel.
.LP
\(em
The channel is identified by the channel number.
.LP
.rs
.sp 15P
.ad r
BLANC
.ad b
.RT
.LP
.bp
.sp 1P
.LP
\fIExample b)\fR
.sp 9p
.RT
.ce
\fBH.T. [T188.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Channel identification
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 1 1 0 0 0 Octets 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 1 0 1 Octets 2
.T&
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 1 0 0 0 0 1 Octets 3
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(36p) | lw(24p) .
Ext. Int. id. present Int. type Spare Pref./ Excl. D\(hych. id. Ch. sel.
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 0 1 0 0 1 1 Octets 3.2
.T&
lw(18p) | cw(36p) | cw(18p) | cw(72p) | lw(24p) .
Coding standard No./Map Ch. type/Map type
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 0 0 Octets 3.3.1
Ch. number/Slot map
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 0 0 Octets 3.3.2
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 0 1 Octets 3.3.3
.TE
.nr PS 9
.RT
.ad r
\fBTable [T188.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
\(em
Same as a) but the channel is identified by slot\(hymap (1544 kbit/s
primary rate interface).
.sp 1P
.LP
\fIExample c)\fR
.sp 9p
.RT
.ce
\fBH.T. [T189.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Channel identification
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 1 1 0 0 0 Octets 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 0 1 Octets 2
.T&
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 1 0 0 0 1 1 Octets 3
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(36p) | lw(24p) .
Ext. Int. id. present Int. type Spare Pref./ Excl. D\(hych. id. Ch. sel.
.TE
.nr PS 9
.RT
.ad r
\fBTable [T189.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
\(em
Same as a) but the channel may be any channel.
.bp
.sp 2P
.LP
H.2.3
\fIPrimary rate interface, circuit mode, H0\(hychannel\fR
.sp 1P
.RT
.sp 1P
.LP
\fIExample a)\fR
.sp 9p
.RT
.ce
\fBH.T. [T190.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Channel identification
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 1 1 0 0 0 Octets 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 1 1 Octets 2
.T&
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 1 0 0 0 0 1 Octets 3
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(36p) | lw(24p) .
Ext. Int. id. present Int. type Spare Pref./ Excl. D\(hych. id. Ch. sel.
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 0 0 0 1 1 0 Octets 3.2
.T&
lw(18p) | cw(36p) | cw(18p) | cw(72p) | lw(24p) .
Coding standard No./Map Ch. type/Map type
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 0 1 Octets 3.3
Ch. number/Slot map
.T&
lw(144p) .
.TE
.nr PS 9
.RT
.ad r
\fBTableau [T190.931], p. 17\fR
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
\(em
The channel is a H0\(hychannel.
.LP
\(em
The indicated channel is preferred.
.LP
\(em
The channel is located in the same interface as
the D\(hychannel.
.LP
\(em
The channel is identified by the channel number.
.LP
.rs
.sp 15P
.ad r
BLANC
.ad b
.RT
.LP
.bp
.sp 1P
.LP
\fIExample b)\fR
.sp 9p
.RT
.ce
\fBH.T. [T191.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Channel identification
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 1 1 0 0 0 Octets 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 1 1 Octets 2
.T&
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 1 0 0 0 0 1 Octets 3
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(36p) | lw(24p) .
Ext. Int. id. present Int. type Spare Pref./ Excl. D\(hych. id. Ch. sel.
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 0 1 0 1 1 0 Octets 3.2
.T&
lw(18p) | cw(36p) | cw(18p) | cw(72p) | lw(24p) .
Coding standard No./Map Ch. type/Map type
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 1 0 Octets 3.3
.T&
cw(144p) | lw(24p) .
Ch. number/Slot map
.TE
.nr PS 9
.RT
.ad r
\fBTable [T191.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
\(em
As for a) but channel indicated by slot map.
.LP
.rs
.sp 23P
.ad r
BLANC
.ad b
.RT
.LP
.bp
.sp 1P
.LP
\fIExample c)\fR
.sp 9p
.RT
.ce
\fBH.T. [T192.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Channel identification
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 1 1 0 0 0 Octets 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 1 0 1 Octets 2
.T&
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 1 0 0 0 0 1 Octets 3
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(36p) | lw(24p) .
Ext. Int. id. present Int. type Spare Pref./ Excl. D\(hych. id. Ch. sel.
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 0 1 0 0 1 1 Octets 3.2
.T&
lw(18p) | cw(36p) | cw(18p) | cw(72p) | lw(24p) .
Coding standard No./Map Ch. type/Map type
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 0 1 Octets 3.3.1
.T&
cw(144p) | lw(24p) .
Ch. number/Slot map
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 1 1 0 1 0 0 1 Octets 3.3.2
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 1 0 0 0 0 0 0 Octets 3.3.3
.TE
.nr PS 9
.RT
.ad r
\fBTable [T192.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
\(em
The channels are B\(hychannels (6 B\(hychannels to form a H0\(hychannel).
.LP
\(em
Channels indicated by slot\(hymap (1544 kbit/s primary rate system).
.LP
\(em
Otherwise as for a).
.LP
.rs
.sp 14P
.ad r
BLANC
.ad b
.RT
.LP
.bp
.sp 1P
.LP
\fIExample d)\fR
.sp 9p
.RT
.ce
\fBH.T. [T193.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Channel identification
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 1 1 0 0 0 Octets 1
.T&
lw(18p) | cw(126p) | lw(24p) .
{
Information element identifier
}
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 0 1 0 Octets 2
.T&
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 1 1 0 0 0 1 1 Octets 3
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(36p) | lw(24p) .
Ext. Int. id. present Int. type Spare Pref./ Excl. D\(hych. id. Ch. sel.
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 0 0 0 0 0 0 Octets 3.1
.T&
cw(144p) | lw(24p) .
Interface identifier
.TE
.nr PS 9
.RT
.ad r
\fBTableau [T193.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
\(em
Any channel.
.LP
\(em
Any interface (int. id. present = 1 and interface identifier =
all \*Q0\*U.
.LP
.rs
.sp 20P
.ad r
BLANC
.ad b
.RT
.LP
.bp
.sp 2P
.LP
H.3
\fICalled/calling party sub\(hyaddress information element\fR
.sp 1P
.RT
.sp 1P
.LP
H.3.1
\fICoding of IA5 sub\(hyaddress digits\fR
.sp 9p
.RT
.ce
\fBH.T. [T194.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(144p) .
Bits
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(24p) .
8 7 6 5 4 3 2 1 Octets
.T&
lw(18p) | cw(126p) | lw(24p) .
Called party sub\(hyaddress
.T&
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 1 1 1 0 0 0 1 Octets 1
.T&
lw(18p) | cw(126p) | lw(24p) .
Information element
.T&
lw(144p) .
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 0 0 0 0 1 0 1 Octets 2
.T&
cw(144p) | lw(24p) .
Length
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
1 0 0 0 0 0 0 0 Octets 3
.T&
cw(18p) | cw(54p) | cw(18p) | cw(54p) | lw(24p) .
Ext. NSAP (X.213/ISO 8348 AD2) Odd/even indication (Note 4) Spare
.T&
cw(144p) | lw(24p) .
AFI (Note 1)
.TE
.TS
center box ;
cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | cw(18p) | lw(24p) .
0 1 0 1 0 0 0 0 Octets 4
.T&
cw(144p) | lw(24p) .
IA5 character (Note 2) Octets 5
.T&
cw(144p) | lw(24p) .
IA5 character Octets 6
.T&
cw(144p) | lw(24p) .
IA5 character Octets 7
.TE
.nr PS 9
.RT
.ad r
\fBTable [T194.931], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 12P
.ad r
BLANC
.ad b
.RT
.LP
.bp
.ce 1000
ANNEX\ I
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBUse of progress indicators\fR
.sp 1P
.RT
.ce 0
.PP
\fR
This Annex describes the use of the different progress indicator values
defined in \(sc\ 4.5.22. Examples of use are given.
.sp 1P
.RT
.PP
\fIProgress indicator No. 1\fR | ndicates that interworking with a
non\(hyISDN has occurred within the network or networks through which the
call has traversed.
.PP
\fIProgress indicator No. 2\fR | ndicates that the destination user is
not ISDN.
.PP
\fIProgress indicator No. 3\fR | ndicates that the origination user is
not ISDN.
.PP
\fIProgress indicator No. 4\fR | ndicates that a call which had left the
ISDN has returned to the ISDN at the same point it had left due to redirection
within the non\(hyISDN. This progress indicator would be employed when
a prior
Recommendation\ Q.931 message resulted in a progress indicator No.\ 1,
\fIcall is\fR \fInot end\(hyto\(hyend ISDN\fR being delivered to the calling
user.
.PP
The use of progress indicators Nos. 1, 2 and 3 is exemplified in
the following.
.PP
Three interworking situations are identified in the figure
below:
.RT
.LP
a)
interworking with another network;
.LP
b)
interworking with a non\(hyISDN user connected to ISDN;
.LP
c)
interworking with non\(hyISDN equipment within the calling or called
user's premises.
.LP
.rs
.sp 17P
.ad r
\fBFigure, p.\fR
.sp 1P
.RT
.ad b
.RT
.PP
As regards calls from A the following applies:
.LP
case\ a)
\(em
progress indicator No. 1 sent to A;
.LP
case\ b)
\(em
progress indicator No. 2 sent to A;
.LP
case\ c)
\(em
progress indicator No. 2 sent to A (location
sub\(hyfield = private network).
.PP
As regards calls towards A the following applies:
.LP
case\ a)
\(em
progress indicator No. 1 sent to A;
.LP
case\ b)
\(em
progress indicator No. 3 sent to A;
.LP
case\ c)
\(em
progress indicator No. 3 sent to A (location
sub\(hyfield = private network).
.PP
The use of progress indicator No. 8, \fIin\(hyband information or\fR
\fIappropriate pattern now available\fR , is described in \(sc\ 5.
.bp
.ce 1000
ANNEX\ J
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBExamples of cause value and location for busy condition\fR
.sp 1P
.RT
.ce 0
.PP
This Annex gives examples on the detailed cause value and
location to be sent in a Cause information element for the busy condition.
.sp 1P
.RT
.PP
Figure J\(hy1/Q.931 shows the reference configuration which
identifies nodes where busy condition may occur and therefore a cause should
be generated.
.PP
Table J\(hy1/Q.931 shows:
.RT
.LP
a)
a cause value and location to be generated at the point
where the busy condition occurs; and
.LP
b)
a cause value and location to be delivered to the user
(indicated as A) for each location (B \(em P) where the busy condition
occurs.
.PP
As is indicated in the Table, the cause value is not changed but the location
may be changed in the receiving exchange, when the cause value
crosses a network boundary.
.LP
.rs
.sp 35P
.ad r
\fBFigure J\(hy1/Q.931, p. 23\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [T195.931]\fR
.ce
TABLE\ J\(hy1/Q.931
.ce
\fBLocation where busy occurs and the cause codings
.ce
\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(60p) | cw(60p) | cw(60p) .
Location where busy occurs {
Cause at the point of generation
} Cause received by user A
_
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
B incoming circuit No. 34 or No. 44 LPN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
B outgoing circuit No. 34 LPN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
C outgoing circuit No. 34 LPN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
D incoming circuit No. 34 or No. 44 LN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
D outgoing circuit No. 34 LN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
E outgoing circuit No. 34 LN The same as left
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
F outgoing circuit No. 34 TN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
G outgoing circuit No. 34 TN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
H outgoing circuit No. 34 INTL
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
I outgoing circuit No. 34 INTL
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
J outgoing circuit No. 34 TN No. 34 TN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
K outgoing circuit No. 34 TN No. 34 TN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
L outgoing circuit No. 34 LN No. 34 RLN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
M outgoing circuit No. 17 LN No. 17 RLN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
N incoming circuit No. 34 or No. 44 LPN No. 34 or No. 44 RPN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
N outgoing circuit No. 34 LPN No. 34 RPN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
O outgoing circuit No. 17 LPN No. 17 RPN
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
P incoming circuit No. 34 or No. 44 U No. 34 or No. 44 U
.T&
lw(60p) | lw(42p) | lw(18p) | lw(42p) | lw(18p) .
P call control No. 17 U No. 17 U
.TE
.LP
LPN
Private network serving the local user
.LP
LN
Public network serving the local user
.LP
TN
Transit network
.LP
INTL
International transit network
.LP
RLN
Public network serving the remote user
.LP
RPN
Private network serving the remote user
.LP
U
User
.LP
Table J\(hy1/Q.931 is for further study.
.nr PS 9
.RT
.ad r
\fBTableau J\(hy1/Q.931 [T195.931], p. 24\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 06P
.ad r
BLANC
.ad b
.RT
.LP
.bp
.ce 1000
ANNEX\ K
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBMessage segmentation procedures\fR
.sp 1P
.RT
.ce 0
.LP
K.1
\fIIntroduction\fR
.sp 1P
.RT
.PP
Layer 3 messages that are longer than the length of frames that the data
link layer can support may be partitioned into several segments.
.PP
Message segmentation shall only be used when the message length
exceeds N.201 (defined in Recommendation\ Q.921\ [3]). These procedures are
optional and may not be supported by all equipment.
.PP
The architectural relationship to other Recommendation\ Q.931 functions
is shown in Figure\ K\(hy1/Q.931. These procedures apply only within a
specific
data link connection and do not impact the procedures in operation on other
parallel data link connections.
.RT
.LP
.rs
.sp 26P
.ad r
\fBFigure K\(hy1/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
K.2
\fIMessage segmentation\fR
.sp 9p
.RT
.PP
The following rules apply when Recommendation Q.931 messages are
to be segmented for transmission:
.RT
.LP
a)
the default maximum number of message segments is eight.
If the message is too long to be segmented then a local
maintenance activity shall be notified;
.LP
b)
the first message segment shall begin with the protocol
discriminator immediately followed by the Call reference, the
segment message type, the Segmented message information element,
and one or more other information elements;
.LP
c)
each subsequent message segment shall begin with the
protocol discriminator immediately followed by the call
reference, the segment message type, the Segmented message
information element and one or more other information elements;
.bp
.LP
d)
the first segment indicator field of the Segmented message
information element shall be set to indicate the first segment
of a segmented message, and not set in any other segment;
.LP
e)
the number of segments remaining field of the Segmented
message information element shall be set to indicate how many
more segments are to be sent, see Figure\ K\(hy2/Q.931;
.LP
f
)
the Message type information element shall be coded
to indicate a segment message, and the Segmented message
information element shall indicate the message type of the
original message;
.LP
g)
the transmission of a segmented message may be aborted by:
sending a message or message segment containing a different call
reference; sending a message with the message type not coded
\*Qsegment message\*U or stopping the transmission of subsequent
message segments pertaining to the same message;
.LP
h)
once the first segment has been transmitted on a
particular data link connection, then all remaining segments of
that message shall be sent (in order) before any other message
(segmented or not) for any other call reference is sent on that
data link connection;
.LP
i)
messages shall be segmented only at information element
boundaries; i.e.,\ no information element shall be separated
into two segments;
.LP
j
)
the information element order as a whole is
preserved for the Segmented message regardless of segment
boundary.
.sp 1P
.LP
K.3
\fIReassembly of segmented messages\fR
.sp 9p
.RT
.PP
The following rules apply to the receipt and reassembly of
segmented Q.931 messages:
.RT
.LP
a)
a reassembly function, on receiving a message segment
containing the Segmented message information element with the
first segment indicator indicating \*Qfirst message\*U, and
containing the call reference and message type (coded as
\*Qsegment message\*U shall enter the Receiving Segmented Message
state and accumulate message segments;
.LP
b)
timer T314, shall be initialized or reinitialized upon
receipt of a message segment containing the Segmented message
information element with a non\(hyzero number of segments remaining
field. Timer\ T314 shall be stopped upon receipt of the last
segment; i.e.,\ a message segment containing the segmented
message information element with the number of segments
remaining field coded zero. Timer\ T314 shall not be initialized
or reinitialized if error procedures as identified in rules
below are initiated;
.LP
c)
a reassembly function receiving a message segment with a
segmented message information element should wait for receipt of
the last message segment pertaining to the same message
i.e.,\ containing the segmented message information element with
the number of segments remaining field coded zero before
delivering the message for further Q.931 processing
as specified in \(sc\ 5.8. The reassembly function shall enter the
Null state;
.LP
d)
upon expiry of timer T314, the reassembly function shall:
discard all segments of this message so far received; notify the
layer\ 3 management entity for the data link connection that
message segments have been lost; and enter the Null state.
.LP
\fINote\fR \ \(em\ Subsequent message segments relating to the same
message shall be discarded according to rule\ f
).
.LP
e)
a reassembly function, upon receiving eight message
segments of the same segmented message without receiving a
message segment with a number of segments remaining field of the
Segmented message information element coded zero, shall: discard
all message segments so far received; notify the layer\ 3
management entity for the data link connection that messages
have been discarded; and enter the Null state;
.LP
\fINote\fR \ \(em\ Subsequent message segments relating to the same
message shall be discarded according to rule\ f
).
.LP
f
)
a reassembly function, on receiving a message segment
containing a Segmented message information element, but with no
call reference or Message type information element, while in the
Null state shall discard that message segment and remain in the
Null state;
.bp
.LP
.rs
.sp 47P
.ad r
\fBFigure K\(hy2/Q.931, p. 26\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
g)
a reassembly function, on receiving a message segment
containing a Segmented message information element, while in the
Receiving Segmented Message state with the number of segments
remaining field that is not decremented from the number
of segments remaining field in the Segmented message information
element of the previous message segment, shall discard all
segments of this message so far received; and enter the Null
state;
.LP
\fINote\fR \ \(em\ Subsequent message segments relating to the same
message shall be discarded according to rule\ f
).
.LP
h)
if there is a DL
\(ulRELEASE
\(ulINDICATION primitive or
DL
\(ulESTABLISH
\(ulINDICATION primitive received while in the
Receiving Segmented Message state, the reassembly function
shall: discard all received message segments so far received;
forward the DL
\(ulRELEASE
\(ulINDICATION primitive or
DL
\(ulESTABLISH
\(ulINDICATION primitive for further Q.931
processing, and enter the null state;
.LP
i)
a reassembly function, upon receiving a message segment
with the first segment indicator of the Segmented message
information element indicating \*Qsubsequent\*U, while in the Null
state, shall: discard that message segment; and remain in the
Null state.
.LP
.rs
.sp 39P
.ad r
\fBFigure K\(hy3/Q.931, p. 27\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 47P
.ad r
\fBFigure K\(hy4/Q.931, p. 28\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 47P
.ad r
\fBFigure K\(hy5/Q.931 (feuillet 1 sur 3), p. 29\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 47P
.ad r
\fBFigure K\(hy5/Q.931 (feuillet 2 sur 3), p. 30\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 20P
.ad r
\fBFigure K\(hy5/Q.931 (feuillet 3 sur 3), p. 31\fR
.sp 1P
.RT
.ad b
.RT
.ce 1000
ANNEX\ L
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBLow layer information coding principles\fR
.sp 1P
.RT
.ce 0
.LP
\fR L.1
\fIPurpose\fR
.sp 1P
.RT
.PP
This Annex describes principles that shall be used when the calling user
specifies information during call setup regarding low layer capabilities
required in the network and by the destination terminal.
.PP
\fINote\fR \ \(em\ In this context and throughout this Annex the term \*Qcalled
user\*U is the end point entity which is explicitly addressed. This may be an
addressed interworking unit (IWU) (see I.500\(hySeries Recommendations [51] and
X.31\ [14] case\ A).
.RT
.sp 2P
.LP
L.2
\fIPrinciples\fR
.sp 1P
.RT
.sp 1P
.LP
L.2.1
\fIDefinitions of types of information\fR
.sp 9p
.RT
.PP
There are three different types of information that the calling
ISDN user may specify during call setup to identify low layer capabilities
needed in the network and by the destination terminal:
.RT
.LP
a)
\fBtype I information\fR is information about the calling
terminal which is only used at the destination end to allow a
decision regarding terminal compatibility. An example would be
modem type. This information is encoded in octets\ 5 to\ 7 of the
Low layer compatibility information element;
.bp
.LP
b)
\fBtype II information\fR is the selection of bearer service
from the choices of bearer services offered by the network to
which the calling user is connected. This type of information is
present even if no interworking occurs. An example is
unrestricted digital information (UDI). This information is
coded in:
.LP
i)
octets 3 and 4 (including octets 4a and 4b if
necessary) of the Bearer capability information element
when the transfer mode required by the calling user is
circuit mode,
.LP
ii)
octets 3, 4, 6 and 7 (including 4a and 4b if
necessary) of the Bearer capability information element
when the transfer mode required by the calling user is
packet mode;
.LP
c)
\fBtype III information\fR is information about the terminal
or intended call which is used to decide destination
terminal compatibility and possibly to facilitate interworking
with other ISDNs or other dedicated networks. An example is
A\(hylaw encoding. This information is encoded in octet 5 of the
Bearer capability information element.
.sp 1P
.LP
L.2.2
\fIExamination by network\fR
.sp 9p
.RT
.PP
Type I information is user\(hyto\(hyuser (i.e. not examined by network)
while both types\ II and\ III should be available for examination by the
destination user and the network. The Low layer compatibility information
element
is an information element which is not examined by the network while the
Bearer capability information element is an information element which is
examined by the user and the network.
.RT
.sp 1P
.LP
L.2.3
\fILocation of type I information\fR
.sp 9p
.RT
.PP
Type I information (i.e. terminal information only significant to the called
user) shall, when used, be included in the Low layer compatibility information
element.
.RT
.sp 1P
.LP
L.2.4
\fILocation of types II and III information\fR
.sp 9p
.RT
.PP
Type II (i.e. bearer selection) information shall be included in
the Bearer capability information element. Type III\ information, when used,
is included in the Bearer capability information element. The network may
use and modify the information (e.g.\ to provide interworking). The rationale
for
the user including some terminal related information in the type\ III
information (interworking related) is shown by the following example.
.PP
Normally with UDI, the rate adaption technique chosen is related
to the terminal. The specification of a particular rate adaption scheme
with a UDI bearer service could allow a compatibility decision by the destination
terminal in a purely ISDN situation. However, it could also conceivably
be used to allow interworking with a PSTN, assuming that the appropriate
functions
(i.e.,\ data extraction, modem pool) are available at the interworking unit.
.PP
If the rate adaption information is carried in the Low layer
compatibility information element, and not in the Bearer capability information
element, then interworking by the network providing the bearer capability
would not be possible. However, if the rate adaption information is carried
in the
Bearer capability information element, interworking would be possible.
.PP
Hence, there is some terminal related information which may be
considered interworking related. The consequence for the calling user of not
including such terminal related information in the Bearer capability
information element is that the call may not be completed if an interworking
situation is encountered.
.RT
.sp 1P
.LP
L.2.5
\fIRelationship between Bearer capability and Low layer\fR
\fIcompatibility information elements\fR
.sp 9p
.RT
.PP
There shall be no contradiction of information between the Low
layer compatibility and the Bearer capability at the originating side.
However, as some Bearer capability code points may be modified during the
transport of the call, this principle implies that there should be minimal
duplication of
information between Bearer capability information element and Low layer
compatibility information element.
.PP
\fINote\fR \ \(em\ If as a result of duplication, a contradiction occurs
between the Bearer capability information element and the Low layer compatibility
information element at the terminating side, the receiving entity shall
ignore the conflicting information in the Low layer compatibility information
element.
.bp
.PP
The following example, dealing with the specification of the
encoding scheme used by the terminal for the speech or 3.1\ kHz audio bearer
services, shows the consequences of duplication.
.PP
It is expected that some ISDNs will support only A\(hylaw and some
only \(*m\(hylaw, with conversion provided by the \(*m\(hylaw network. (See
Recommendation\ G.711.) If the encoding scheme is specified in both the
Bearer capability information element and the Low layer compatibility information
element, interworking between two ISDNs might require a change of the user
information layer 1 protocol in the Bearer capability information element
(e.g.\ from A\(hylaw to \(*m\(hylaw), while the encoding scheme specified
in the Low
layer compatibility information element would presumably be forwarded to the
destination unchanged. Since, to determine compatibility, the destination
terminal examines both the Bearer capability information element and the Low
layer compatibility information element, it would receive conflicting
information regarding the encoding scheme used.
.RT
.sp 1P
.LP
L.3
\fIInformation classification\fR
.sp 9p
.RT
.PP
The following are the examples of classifying low layer
information currently identified. This information is provided to facilitate
understanding of the characteristics of types\ II and\ III information.
.RT
.sp 1P
.LP
L.3.1
\fIExamples for speech and 3.1 kHz audio bearer services\fR
.sp 9p
.RT
.LP
a)
Type II information (common to all applications using these
bearer services):
.LP
\(em
information transfer capability = speech or 3.1 kHz
audio;
.LP
\(em
information transfer mode = circuit;
.LP
\(em
information transfer rate = 64 kbit/s;
.LP
\(em
user information layer 1 protocol = A/\(*m law.
.LP
b)
Type III information for interworking with CSPDN (3.1 kHz
audio applications are assumed) \(em Figure\ L\(hy1/Q.931:
.LP
\(em
user information layer 1 protocol = rate adaption +
user rate (Note);
.LP
\fINote\fR \ \(em\ Only those profiles conforming to CCITT
standardized rate adaption are allowed when only the above
information is provided.
.LP
c)
Type III information for interworking with PSTN:
.LP
i)
voice applications: Figure L\(hy2/Q.931:
.LP
\(em
user information layer 1 protocol = A/\(*m law;
.LP
ii)
voice band data applications: Figure L\(hy3/Q.931:
.LP
\(em
user information layer 1 protocol = A/\(*m
law.
.LP
.rs
.sp 14P
.ad r
\fBFigure L\(hy1/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 10P
.ad r
\fBFigure L\(hy2/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 10P
.ad r
\fBFigure L\(hy3/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
L.3.2
\fIExamples for 64 kbit/s UDI circuit mode bearer service\fR
.sp 9p
.RT
.LP
a)
Type II information (common):
.LP
\(em
information transfer capability = unrestricted
digital information;
.LP
\(em
information transfer mode = circuit;
.LP
\(em
information transfer rate = 64 kbit/s.
.LP
b)
Type III information for interworking with PSPDN (packet
applications): Figure\ L\(hy4/Q.931:
.LP
\(em
no type III information is required.
.LP
c)
Type III information for interworking with PSTN:
.LP
i)
voice applications: Figure L\(hy5/Q.931:
.LP
\(em
no type III information is required;
.LP
ii)
rate\(hyadapted data applications: Figure L\(hy6/Q.931
.LP
\(em
no type III information is required.
.LP
d)
Type III information for interworking with PSTN with
end\(hyto\(hyend digital connectivity (data applications)
Figure\ L\(hy7/Q.931:
.LP
\(em
user information layer 1 protocol = rate adaption +
user rate (Note).
.LP
\fINote\fR \ \(em\ The profile described in I.463 [52]
is allowed.
.sp 1P
.LP
L.3.3
\fIExamples for ISDN virtual\(hycircuit bearer service\fR
.sp 9p
.RT
.LP
a)
Type II information (common):
.LP
\(em
information transfer capability = unrestricted digital
information;
.LP
\(em
information transfer mode = packet;
.LP
\(em
information transfer rate = \(em\(em\(em;
.bp
.LP
\(em
user information layer 1 protocol = rate adaption +
user rate (Note\ 1);
.LP
\(em
user information layer 2 protocol = LAPB (Note 2);
.LP
\(em
user information layer 3 protocol = X.25 [5] packet
layer protocol (Note\ 2).
.LP
\fINote\ 1\fR \ \(em\ This parameter is included only when user
packet information flow is rate adapted. Only those
profiles conforming to X.31 are allowed when only the above
information is provided for layer\ 1 protocol.
.LP
\fINote\ 2\fR \ \(em\ Only those profiles conforming to X.31 are
used. See Figures\ L\(hy8/Q.931, L\(hy9/Q.931 and L\(hy10/Q.931.
.LP
b)
Type III information for interworking with PSPDN, CSPDN,
PSTN:
.LP
\(em
no type III information is necessary.
.LP
.rs
.sp 11P
.ad r
\fBFigure L\(hy4/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 10P
.ad r
\fBFigure L\(hy5/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 11P
.ad r
\fBFigure L\(hy6/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 10P
.ad r
\fBFigure L\(hy7/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 9P
.ad r
\fBFigure L\(hy8/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 10P
.ad r
\fBFigure L\(hy9/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 9P
.ad r
\fBFigure L\(hy10/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 2P
.LP
L.4
\fIScenarios outside the scope of ISDN standardization\fR
.sp 1P
.RT
.sp 1P
.LP
L.4.1
\fIExamples for speech and 3.1 kHz audio bearer services\fR
.sp 9p
.RT
.LP
a)
Type II information (common):
.LP
\(em
information transfer capability = speech or 3.1 kHz
audio;
.LP
\(em
information transfer mode = circuit;
.LP
\(em
information transfer rate = 64 kbit/s;
.LP
\(em
user information layer 1 protocol = A/\(*m law.
.LP
b)
Type III information for interworking with PSTN \(em voice band
data applications \(em modem type conversion occurs:
Figure\ L\(hy11/Q.931:
.LP
\(em
user information layer 1 protocol = rate adaption +
user rate + other attributes (if required).
.sp 1P
.LP
L.4.2
\fIExamples for 64 kbit/s UDI circuit mode bearer services\fR
.sp 9p
.RT
.LP
a)
Type II information (common):
.LP
\(em
information transfer capability = unrestricted digital
information;
.LP
\(em
information transfer mode = circuit;
.LP
\(em
information transfer rate = 64 kbit/s.
.LP
b)
Type III information for interworking with PSTN \(em voice band
data applications \(em
Figure\ L\(hy12/Q.931:
.LP
\(em
no type III information is required.
.LP
.rs
.sp 12P
.ad r
\fBFigure L\(hy11/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 13P
.ad r
\fBFigure L\(hy12/Q.931, p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce 1000
ANNEX\ M
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBLow layer compatibility negotiation\fR
.sp 1P
.RT
.ce 0
.PP
\fR
This Annex describes an additional low layer compatibility
checking procedure that may be applied by the user. However, this is a
network option and may not be supported by all networks.
.sp 1P
.RT
.sp 1P
.LP
M.1
\fIGeneral\fR
.sp 9p
.RT
.PP
The purpose of the Low layer compatibility information element is to provide
a means which should be used for compatibility checking by an
addressed entity (e.g.,\ a remote user or an interworking unit or high layer
function network node addressed by the calling user). The Low layer
compatibility information element is transferred transparently by an ISDN
between the call originating entity (e.g.,\ the caller user) and the addressed
entity.
.PP
The user information protocol fields of the Low layer compatibility
information element indicate the low layer attributes at the call originating
entity and the addressed entity. This information is not interpreted by
the
ISDN and therefore the bearer capability provided by the ISDN is not affected
by this information. The call originating entity and the addressed entity
may modify the low layer attributes by the negotiation described below
if that can be supported by the bearer capability actually provided by
the ISDN.
.PP
The Low layer compatibility information element is coded according to \(sc\
4.5.18.
.RT
.sp 1P
.LP
M.2
\fILow layer compatibility notification to the called user\fR
.sp 9p
.RT
.PP
When the calling user wishes to notify the called user of any
information transfer attribute (contained octet\ 3 to\ 4b) different from the
ones contained in the Bearer capability information element or of any low
layer protocol to be used during the call and not already identified in
the Bearer
capability information element, then the calling user shall include a Low
layer compatibility information element in the SETUP message; this element
is
conveyed by the network and delivered to the called user. However, if the
network is unable to convey this information element, it shall act as described
in \(sc\ 5.8.7.1 (unrecognized information element).
.RT
.sp 1P
.LP
M.3
\fILow layer compatibility negotiation between users\fR
.sp 9p
.RT
.PP
If the negotiation indicator (see \(sc\ 4.5) of the Low layer
compatibility information element included in the SETUP message is set to
\*QOut\(hyband LLC negotiation allowed\*U, then one or more of the low
layer protocol attribute(s) may be negotiated. In this case, the called
user responding
positively to the call may include a Low layer compatibility information
element in the CONNECT message. This element will be conveyed transparently
by the network and delivered to the calling user in the CONNECT message.
.PP
\fINote\fR \ \(em\ Only the low layer protocol attributes may be negotiated
and therefore the information transfer attributes (octets\ 3 to\ 4), if
returned by the called user in the CONNECT message, will be identical to
the ones received in the Low layer compatibility information element contained
in the SETUP
message.
.PP
If, for any reason, the network is unable to convey this information element,
it shall act as described in \(sc\ 5.8.7.1 (unrecognized information
element). Users are advised not to include in the Low layer compatibility
information element sent from the called user to the calling user, attributes
which would have the same value as the ones contained in the Low layer
compatibility information element received from the calling party.
.RT
.sp 1P
.LP
M.4
\fILow layer compatibility negotiation options\fR
.sp 9p
.RT
.PP
The Low layer compatibility information element contains a
negotiation indicator which may have one of the following values:
.RT
.LP
a)
low layer compatibility negotiation not allowed (default):
then the called user shall not invoke negotiation;
.LP
b)
out\(hyband low layer compatibility negotiation allowed: the
called user may then invoke low layer compatibility negotiation,
as needed, according to \(sc\ M.3;
.bp
.LP
c)
in\(hyband negotiation allowed: the called user may then
invoke low layer compatibility negotiation using the supported
in\(hyband negotiation, according to service or application
requirements;
.LP
d)
either in\(hyband or out\(hyband negotiation allowed: the called
user may invoke one or the other low layer compatibility
negotiation procedures according to its requirements. If the
call is end\(hyto\(hyend ISDN, and the out\(hyband low layer
compatibility negotiation is supported by both parties, then
this method of negotiation is preferred.
\v'1P'
.ce 1000
ANNEX\ N
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBProcedures for establishment of bearer connection\fR
.sp 1P
.RT
.ce 0
.ce 1000
\fBprior to call acceptance\fR
.ce 0
.LP
\fR N.1
\fIGeneral\fR
.sp 1P
.RT
.PP
For some applications, it is desirable to allow the completion of the transmission
path associated with a bearer service prior to receiving call acceptance.
In particular, the completion of the backward direction of the
transmission path prior to receipt of a CONNECT message from the called user
may be desirable to:
.RT
.LP
a)
allow the called user to provide internally\(hygenerated tones
and announcements that are sent in\(hyband to the calling user
prior to answer by the called user; or
.LP
b)
avoid speech clipping on connections involving an NT2
where delays may occur in relaying the answer indication within
the called user equipment.
.PP
The procedures described in this Annex are only applicable to the speech
and 3.1\ kHz audio bearer services.
.PP
\fINote\fR \ \(em\ The definition of necessary mechanisms (if any) with
Signalling System No.\ 7 to avoid any potential undesirable charging
implications remains for further study.
.RT
.sp 1P
.LP
N.2
\fIProcedures\fR
.sp 9p
.RT
.PP
As a network option, completion of the transmission path prior to receipt
of a call acceptance indication may be provided in one of three
ways:
.RT
.LP
a)
on completion of successful channel negotiation at the
destination interface; or
.LP
b)
on receipt of a message containing an indication that
in\(hyband information is being provided; or
.LP
c)
not at all: i.e., this option is not supported by the
network.
.PP
When criteria a) is used to determine that transmission path
should be established, the network shall connect, as a minimum, the backward
side of the transmission path upon receipt of either a CALL PROCEEDING
message or an ALERTING message containing an acceptable B\(hychannel indication.
.PP
When criteria b) is used to establish the transmission path, the
network shall connect, as a minimum, the backward side of the transmission
path upon receipt of either an ALERTING message or a PROGRESS message containing
progress indicator No.\ 8, \fIin\(hyband information or appropriate pattern
now\fR
\fIavailable\fR , or progress indicator No.\ 1, \fIcall is not end\(hyto\(hyend
ISDN;\fR
\fIfurther call progress information may be available in\(hyband\fR ,
respectively.
.PP
The network providing the early completion of the transmission path in
the backward direction may choose to support only one of methods\ a) or\
b)
above. The network may choose to further restrict which message(s) will
result in establishment of the transmission path. These restrictions may
be imposed on a per interface basis to provide an administrative means
for limiting potential misuse of the early connection capabilities.
.bp
.RT
.ce 1000
ANNEX\ O
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBOptional procedures for bearer service change\fR
.sp 1P
.RT
.ce 0
.PP
The procedure for bearer service change may not be provided
on all networks. On those networks that support it, a user may use this
procedure after making a suitable subscription\(hytime arrangement.
.sp 1P
.RT
.PP
\fINote\ 1\fR \ \(em\ The definition of necessary mechanisms (if any) within\fR
Signalling System No.\ 7 to support this procedure, including any undesirable
charging implications, is for further study.
.PP
When a bearer service requested in an originator's SETUP message
cannot be provided by the network, the network would reject the call or,
under some circumstances, the network may change the bearer service and
provide
bearer service change notification. These procedures are currently applicable
only to a change from 64\ kbit/s unrestricted to 64\ kbit/s restricted,
and from 64\ kbit/s restricted to 64\ kbit/s restricted with rate adaption.
.PP
\fINote\ 2\fR \ \(em\ During an interim period some networks may only support
restricted 64 kbit/s digital information transfer capability, i.e., information
transfer capability solely restricted by the requirement that the all\(hyzero
octet is not allowed. For interworking the values given in Appendix\ I of
Recommendation\ I.340 should apply. The interworking functions have
to be provided in the network restricted capability. The ISDN with 64\ kbit/s
transfer capabilities will not be offered by this interworking, other than
by conveying the appropriate signalling message to or from the ISDN terminal.
.PP
\fINote\ 3\fR \ \(em\ The possibility of changing from 3.1 kHz audio to
speech is for further study.
.PP
Up to three Bearer capability information elements may be present in the
SETUP message from the originating user, corresponding to the allowed
bearer service modifications given above. The Bearer capability information
element shall be immediately preceded by the Repeat indicator information
element with the meaning field specifying \fIPrioritized list for selecting
one\fR \fIpossibility\fR . Hence, the order of Bearer capability information
elements
would indicate order of bearer service preference.
.PP
If the SETUP message contains Bearer capability information
elements not agreeing with any of the permissible ordered combinations
listed above, the network will reject the call attempt.
.PP
After sending a CALL PROCEEDING message, when the originating network or
terminating premises equipment determines that the preferred bearer service
cannot be provided, it sends a NOTIFY message toward the call orginator.
The
NOTIFY message contains a Notification indicator information element with a
coding which indicates to the originating party the change in bearer service
and also contains a Bearer capability information element specifying the
attributes of the new bearer service.
.PP
Receipt of the NOTIFY message is not acknowledged. The call originator
may allow the call to continue or may initiate call clearing in accordance
with \(sc\ 5.
.RT
.LP
.rs
.sp 11P
.ad r
BLANC
.ad b
.RT
.LP
.bp
.ce 1000
APPENDIX\ I
.ce 0
.ce 1000
(to Recommendation Q.931)
.sp 9p
.RT
.ce 0
.ce 1000
\fBUsage of cause values\fR
.sp 1P
.RT
.ce 0
.PP
Table I\(hy2/Q.931 indicates the usage of cause values within
Recommendation\ Q.931. Other usage may be provided within other Recommendations,
e.g.,\ Q.700\(hySeries and Q.699. Other causes may also be used by Q.931
entities where this is not precluded by the procedures defined elsewhere
in\ Q.931.
.sp 1P
.RT
.PP
Table I\(hy1/Q.931 defines the key for the location of generation in Table\
I\(hy2/Q.931. For more precise usage of the location codes in the cause
information element, see Annex\ J/Q.931.
.ce
\fBH.T. [T196.931]\fR
.ce
TABLE\ I\(hy1/Q.931
.ce
\fBKey for the location of the
.ce
generation in Table I\(hy2/Q.931\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
lw(180p) .
LU Local user
.T&
lw(180p) .
LN Local network\fI\fR
.T&
lw(180p) .
TN Transit network
.T&
lw(180p) .
RN Remote network
.T&
lw(180p) .
RU Remote user
.T&
lw(180p) .
{
LPE
Local peer entity (for symmetrical operation, see Annex D/Q.931)
}
.T&
lw(180p) .
{
The following abbreviations to message types are used in
Table I\(hy2/Q.931
}
.T&
lw(180p) .
CON\ CON CONGESTION CONTROL
.T&
lw(180p) .
DISC DISCONNECT
.T&
lw(180p) .
REL RELEASE
.T&
lw(180p) .
REL\ COM RELEASE COMPLETE
.T&
lw(180p) .
RES\ REJ RESUME REJECT
.T&
lw(180p) .
STAT STATUS
.T&
lw(180p) .
SUSP\ REJ SUSPEND REJECT
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau I\(hy1/Q.931 [T196.931], p. 44\fR
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 15P
.ad r
BLANC
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [1T197.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(342p) .
TABLE\ I\(hy2/Q.931
.T&
cw(342p) .
{
\fBUsage of cause values\fR
}
.TE
.TS
center box ;
cw(24p) | cw(24p) | cw(24p) | cw(54p) | cw(54p) | cw(45p) | cw(39p) | cw(39p) sw(39p) , ^ | ^ | ^ | ^ | ^ | ^ | ^ | c | c.
Cause No. Class Value Cause name Diagnostics Section cross\(hyreference {
Typical location of generation
} {
Typical carrying message as identified by receiving side
}
At remote interface At local interface
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
\ 1 000 0001 {
Unassigned (unallocated) number
} Condition 5.1.4 LN REL COM .line DISC 5.2.4
RU REL COM .line DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
\ 2 000 0010 {
No route to specified transit network
} {
Transit network identity/network specific facilities info. elements
} C.2 TN DISC E.3
LN REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
\ 3 000 0011 No route to destination Condition 5.1.4 LN DISC .line REL COM 5.2.4
RU REL COM .line DISC DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
\ 6 000 0110 Channel unacceptable \(em {
5.2.3.1 | )
5.3.2 | )
6.2.2.3.1
} LN REL
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
\ 7 000 0111 {
Call awarded and being delivered in an established channel
} \(em 6.2.2.3.1 LN REL
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
16 001 0000 Normal call clearing Condition RU DISC DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | l | c | l | l.
17 001 0001 User busy \(em 5.2.5.1 5.2.5.4 | ) RU REL COM DISC
No procedure RN DISC
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau I\(hy2/Q.931 [1T197.931], p. 45 \ \ \
A L'ITALIENNE\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [2T197.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(342p) .
{
TABLE\ I\(hy2/Q.931\ \fI(cont.)\fR
}
.TE
.TS
center box ;
cw(24p) | cw(24p) | cw(24p) | cw(54p) | cw(54p) | cw(45p) | cw(39p) | cw(39p) sw(39p) , ^ | ^ | ^ | ^ | ^ | ^ | ^ | c | c.
Cause No. Class Value Cause name Diagnostics Section cross\(hyreference {
Typical location of generation
} {
Typical carrying message as identified by receiving side
}
At remote interface At local interface
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
18 001 0010 No user responding \(em 5.2.5.3 RN DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
19 001 0011 User alerting, no answer \(em 5.2.5.3 RN DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
21 001 0101 Call rejected {
Condition: user supplied diagnostic
} 5.2.5.1 5.2.5.4 | ) RU REL COM. DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
22 001 0110 Number changed New destination number 5.1.4 LN DISC .line REL COM 5.2.4
RU REL COM .line DISC DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
26 001 1010 Non\(hyselected user clearing \(em 5.3.2 | ) 6.2.2.3.1 LN REL
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
27 001 1011 Destination out of order \(em 5.8.9 RN DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | cw(45p) | lw(39p) | lw(39p) | cw(39p) , ^ | ^ | ^ | ^ | ^ | l | l | l | c
^ | ^ | ^ | ^ | ^ | l | l | c | l
^ | ^ | ^ | ^ | ^ | l | c | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l.
28 001 1100 {
Invalid number format (incomplete number)
} \(em LN REL + .line DISC COM 5.2.4 RU
DISC .line REL COM DISC 5.1.5.2 LN DISC 5.2.4 RN DISC 5.1.4 LN DISC REL COM
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau I\(hy2/Q.931 [2T197.931], p. 46 \ \ \
A L'ITALIENNE\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [3T197.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(342p) .
{
TABLE\ I\(hy2/Q.931\ \fI(cont.)\fR
}
.TE
.TS
center box ;
cw(24p) | cw(24p) | cw(24p) | cw(54p) | cw(54p) | cw(45p) | cw(39p) | cw(39p) sw(39p) , ^ | ^ | ^ | ^ | ^ | ^ | ^ | c | c.
Cause No. Class Value Cause name Diagnostics Section cross\(hyreference {
Typical location of generation
} {
Typical carrying message as identified by receiving side
}
At remote interface At local interface
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | cw(39p) , ^ | ^ | ^ | ^ | ^ | ^ | l | c | l
^ | ^ | ^ | ^ | ^ | ^ | l | l | l.
29 011 1101 Facility rejected Facility identification No procedure in Q.931 LN REL COM .line DISC RN
DISC RU REL COM .line DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
30 001 1110 Response to STATUS ENQUIRY \(em 5.8.10 LU, LN STAT
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
31 001 1111 Normal, unspecified \(em 5.8.4 RN REL COM .line DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l
^ | ^ | ^ | ^ | ^ | c | l | l | l
^ | ^ | ^ | ^ | ^ | c | l | l | c
^ | ^ | ^ | ^ | ^ | l | l | l | l.
34 010 0010 No circuit/channel available \(em 5.1.1 5.1.2 LN REL COM {
5.2.3.1 | )
5.2.3.1 | )
5.2.3.2
6.2.2.3.1
}
RU REL COM. DISC C.2 LN REL COM, .line DISC REL COM, .line DISC C.2 TN DISC D.1.1 | ) D.3 | ) LPE REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | lw(39p) | lw(39p) | lw(39p) .
38 010 0110 Network out of order \(em No procedure
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau I\(hy2/Q.931 [3T197.931], p. 47 \ \ \
A L'ITALIENNE\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [4T197.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(342p) .
{
TABLE\ I\(hy2/Q.931\ \fI(cont.)\fR
}
.TE
.TS
center box ;
cw(24p) | cw(24p) | cw(24p) | cw(54p) | cw(54p) | cw(45p) | cw(39p) | cw(39p) sw(39p) , ^ | ^ | ^ | ^ | ^ | ^ | ^ | c | c.
Cause No. Class Value Cause name Diagnostics Section cross\(hyreference {
Typical location of generation
} {
Typical carrying message as identified by receiving side
}
At remote interface At local interface
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
41 010 1001 Temporary failure \(em 5.8.8 LU, LN DISC 5.8.10
LN, RU, RN DISC DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | lw(39p) | lw(39p) | lw(39p) .
42 010 1010 {
Switching equipment congestion
} \(em No procedure REL REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | c
^ | ^ | ^ | ^ | ^ | l | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l.
43 010 1011 Access information discarded {
Discarded into element identifier(s)
} 7.1.5.7 RU, LN, RU CON CON 7.1.6.1
LN STAT 5.8.7.2 LN, LU STAT
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l.
44 010 1100 {
Requested circuit/channel not available
} \(em 5.1.2 LN REL COM {
5.2.3.1 | )
5.2.3.2
6.2.3.3.1
}
RU REL COM. DISC D.1.1 | ) REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | lw(39p) | lw(39p) | lw(39p) .
47 010 1111 {
Resource unavailable, unspecified
} \(em No procedure
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | lw(39p) | lw(39p) | lw(39p) .
49 011 0001 {
Quality of service unavailable
} Condition 6 REL REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | l | c | l | l
^ | ^ | ^ | ^ | ^ | c | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l.
50 011 0010 {
Requested facility not subscribed
} Facility identification 7.1.3.6 RU DISC .line REL COM DISC
7.1.4.3 7.1.5.3 RN DISC 7.1.7.4 LN REL COM
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau I\(hy2/Q.931 [4T197.931], p. 48 \ \ \
A L'ITALIENNE\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [5T197.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(342p) .
{
TABLE\ I\(hy2/Q.931\ \fI(cont.)\fR
}
.TE
.TS
center box ;
cw(24p) | cw(24p) | cw(24p) | cw(54p) | cw(54p) | cw(45p) | cw(39p) | cw(39p) sw(39p) , ^ | ^ | ^ | ^ | ^ | ^ | ^ | c | c.
Cause No. Class Value Cause name Diagnostics Section cross\(hyreference {
Typical location of generation
} {
Typical carrying message as identified by receiving side
}
At remote interface At local interface
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
57 011 1001 {
Bearer capability not authorized
} {
Attributes of bearer capability
} 5.1.5.2 LN DISC .line REL COM 7.2.2
LN REL .line REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
58 011 1010 {
Bearer capability not presently available
} {
Attributes of bearer capability
} 5.1.5.2 LN DISC .line REL COM 7.2.2
LN REL .line REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
63 011 1111 {
Service or option not available, unspecified
} \(em 5.1.5.2 LN DISC .line REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
65 100 0001 {
Bearer capability not implemented
} {
Attributes of bearer capability
} 5.1.5.2 LN DISC .line REL COM 6.1
LN REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | lw(39p) | lw(39p) | lw(39p) .
66 100 0010 Channel type not implemented Channel type No procedure
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | l | c | l | l
^ | ^ | ^ | ^ | ^ | c | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l.
69 100 0101 {
Resquested facility not implemented
} Facility identification 7.1.3.6 RU DISC .line REL COM DISC
7.1.4.3 7.1.5.3 RN REL DISC 7.1.7.4 LN REL .line REL COM
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau I\(hy2/Q.931 [5T197.931], p. 49 \ \ \
A L'ITALIENNE\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce
\fBH.T. [6T197.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(342p) .
{
TABLE\ I\(hy2/Q.931\ \fI(cont.)\fR
}
.TE
.TS
center box ;
cw(24p) | cw(24p) | cw(24p) | cw(54p) | cw(54p) | cw(45p) | cw(39p) | cw(39p) sw(39p) , ^ | ^ | ^ | ^ | ^ | ^ | ^ | c | c.
Cause No. Class Value Cause name Diagnostics Section cross\(hyreference {
Typical location of generation
} {
Typical carrying message as identified by receiving side
}
At remote interface At local interface
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | lw(39p) | lw(39p) | lw(39p) .
70 100 0110 {
Only restricted digital information bearer capability is available
} \(em {
No procedure (network dependent option)
}
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | lw(39p) | lw(39p) | lw(39p) .
79 100 1111 {
Service or option not implemented, unspecified
}
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | c
^ | ^ | ^ | ^ | ^ | l | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l.
81 101 0001 Invalid call reference value \(em 5.8.3.2 | ) LU, LN REL .line REL COM 5.8.3.2 | )
LU, LN REL COM 5.8.3.2 | ) LU, LN STAT
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | lw(39p) | lw(39p) | lw(39p) .
82 101 0010 {
Identified channel does not exist
} Channel identity No procedure REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
83 101 0011 {
A suspended call exists, but this call identity does not
} \(em 5.6.5 LN RES REJ
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
84 101 0100 Call identity in use \(em 5.6.3 LN SUSP REJ
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
85 101 0101 No call suspended \(em 5.6.5 LN RES REJ
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
86 101 0110 {
Call having the requested call identity has been cleared
} 5.6.5 LN RES REJ
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau I\(hy2/Q.931 [6T197.931], p. 50 \ \ \
A L'ITALIENNE\fR
.sp 1P
.RT
.ad b
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.LP
.bp
.ce
\fBH.T. [7T197.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(342p) .
{
TABLE\ I\(hy2/Q.931\ \fI(cont.)\fR
}
.TE
.TS
center box ;
cw(24p) | cw(24p) | cw(24p) | cw(54p) | cw(54p) | cw(45p) | cw(39p) | cw(39p) sw(39p) , ^ | ^ | ^ | ^ | ^ | ^ | ^ | c | c.
Cause No. Class Value Cause name Diagnostics Section cross\(hyreference {
Typical location of generation
} {
Typical carrying message as identified by receiving side
}
At remote interface At local interface
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
88 101 0111 Incompatible destination Incompatible parameter {
5.2.2
5.2.5.1
5.2.5.3 | )
B.3.2
B.3.3
} RU REL COM DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | cw(54p) | lw(45p) | cw(39p) | lw(39p) | cw(39p) , ^ | ^ | ^ | ^ | ^ | ^ | l | l | l
^ | ^ | ^ | ^ | ^ | ^ | l | l | l.
91 101 1011 {
Invalid transit network selection
} \(em C.2 TN DISC LN
DISC .line REL .line REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
95 101 1111 Invalid message, unspecified Message type 5.8 LN REL COM .line STAT
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
96 110 0000 {
Mandatory information element is missing
} {
Information element identifier(s)
} 5.8.6.1 LN, LU REL .line REL COM .line STAT 5.8.11
LN, LU STAT
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
97 110 0001 {
Message type non\(hyexistent or not implemented
} Message type {
5.8.4
.line
5.8.10
.line
5.8.11
} LU, LN STAT
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
98 110 0010 {
Message not compatible with call state or message type non\(hyexistent
or not implemented
} Message type 5.8.4 LU, LN STAT
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
99 110 0011 {
Information element non\(hyexistent or not implemented
} {
Information element identifier(s)
} 5.8.7.1 .line 5.8.11 LU, LN STAT 5.8.7.1
LN REL .line REL COM
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau I\(hy2/Q.931 [7T197.931], p. 51 \ \ \
A L'ITALIENNE\fR
.sp 1P
.RT
.ad b
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.LP
.bp
.ce
\fBH.T. [8T197.931]\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(342p) .
{
TABLE\ I\(hy2/Q.931\ \fI(end)\fR
}
.TE
.TS
center box ;
cw(24p) | cw(24p) | cw(24p) | cw(54p) | cw(54p) | cw(45p) | cw(39p) | cw(39p) sw(39p) , ^ | ^ | ^ | ^ | ^ | ^ | ^ | c | c.
Cause No. Class Value Cause name Diagnostics Section cross\(hyreference {
Typical location of generation
} {
Typical carrying message as identified by receiving side
}
At remote interface At local interface
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
100 110 0100 {
Invalid information element contents
} {
Information element identifier(s)
} 5.8.6.2 LU, LN {
STAT
.line
REL
.line
REL COM
.line
} 5.8.7.2 .line 5.8.11
LU, LN STAT
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | l.
101 110 0101 {
Message not compatible with call state
} Message type 5.8.4 LN, LU STAT 5.8.11
LN, LU DISC .line REL .line REL COM
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) , ^ | ^ | ^ | ^ | ^ | c | l | l | c
^ | ^ | ^ | ^ | ^ | l | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l
^ | ^ | ^ | ^ | ^ | l | l | l | l.
102 110 0110 Recovery on time expiry Timer number {
5.2.4
.line
5.2.5.3
.line
5.6.5
.line
5.4.1
} LN DISC 5.3.3 .line 5.3.4
LN REL {
5.3.2 | )
.line
5.3.3
.line
5.6.5
} LU REL
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
111 110 1111 Protocol error, unspecified 5.8.4 RN DISC
_
.T&
cw(24p) | cw(24p) | cw(24p) | lw(54p) | lw(54p) | lw(45p) | cw(39p) | lw(39p) | lw(39p) .
127 111 1111 Interworking, unspecified No explicit procedure
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau I\(hy2/Q.931 [8T197.931], p. 52 \ \ \
A L'ITALIENNE\fR
.sp 1P
.RT
.ad b
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.bp