\ \(em\ An ER TPDU shall be sent in certain cases (see \(sc 6.6).
.parag
\fINote\ 2\fR
\ \(em\ If received, it shall be processed as a protocol error
(see \(sc 6.22).
.parag
\fINote\ 3\fR
\ \(em\ A CR with Class 2 has been sent and a CC Class 0 is
received.
.parag
\fINote\ 4\fR
\ \(em\ If DC is not available (i.e. Class 0 only implemented),
or SRC\(hyREF is zero.
.parag
T}
_
.TE
.nr PS 9
.RT
.ad r
\fBTABLEAU A\(hy6/X.224 suite [T34.224], p.32\fR
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 1P
.LP
A.4
\fIState tables for Classes 1 and 3\fR
.sp 9p
.RT
.PP
This section provides a more precise description of a transport
entity for a transport connection of Class\ 1 or Class\ 3.
.PP
The description uses the predicates defined in Table\ A\(hy7/X.224.
.PP
Specific actions are defined in Table A\(hy8/X.224 and specific
additional notes are given in
Table\ A\(hy9/X.224.
.PP
The description does not include a complete specification of the data transfer
procedures but makes reference to the specification of the classes
(see \(sc\(sc\ 9 and\ 11). Table\ A\(hy10/X.224 gives the state automata
for Classes\ 1
and\ 3.
.RT
.LP
.sp 3
.ce
\fBH.T. [T35.224]\fR
.ce
TABLE\ A\(hy7/X.224
.ce
\fBPredicates for classes 1 and 3\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(204p) .
Name Description
_
.T&
cw(24p) | lw(204p) .
P0\ T{
T\(hyCONNECT request unacceptable
T}
_
.T&
cw(24p) | lw(204p) .
P1\ T{
No available network connection can be used for assignment or
reassignment
T}
_
.T&
cw(24p) | lw(204p) .
P2\ T{
A network connection can be used for asignment or reassignment; the
network connection opening is in progress
T}
_
.T&
cw(24p) | lw(204p) .
P3\ T{
A network connection can be used for assignment or reassignment; the
network connection is open
T}
_
.T&
cw(24p) | lw(204p) .
P4\ T{
TTR timer has previously run out
T}
_
.T&
cw(24p) | lw(204p) .
P5\ Local choice
_
.T&
cw(24p) | lw(204p) .
P6\ T{
Initiator of the transport connection
T}
_
.T&
cw(24p) | lw(204p) .
P7\ Unacceptable CR TPDU
_
.T&
cw(24p) | lw(204p) .
P8\ TWR is running
_
.T&
cw(24p) | lw(204p) .
P9\ Class 4 CR
_
.T&
cw(24p) | lw(204p) .
P10 T{
Class selected in CC is class 0 or 2
T}
_
.TE
.nr PS 9
.RT
.ad r
\fBTABLEAU A\(hy7/X.224 [T35.224], p.33\fR
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
.bp
.ce
\fBH.T. [T36.224]\fR
.ce
TABLE\ A\(hy8/X.224
.ce
\fBSpecific actions for classes 1 and 3\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(204p) .
Name Description
_
.T&
cw(24p) | lw(204p) .
\ [1] T{
The network connection can be disconnected if not used by any transport
connection assigned to it.
T}
_
.T&
cw(24p) | lw(204p) .
\ [2] T{
Process TDT request or TEX request which have been stored when
waiting for reassignment (if any). If an RJ TDPU has been received,
enable also data TPDU transmission (if any). If an ED TPDU was received, handle according to procedures for class if not a duplicate.
T}
_
.T&
cw(24p) | lw(204p) .
\ [3] T{
Network connection can be disconnected if not used by any transport
connection and was locally opened.
T}
_
.T&
cw(24p) | lw(204p) .
\ [4] T{
Start TWR timer if not already running. Disable sending DT TPDUs until
an RJ TPDU is received (see Note 3).
T}
_
.T&
cw(24p) | lw(204p) .
\ [5] Stop TWR timer.
_
.T&
cw(24p) | lw(204p) .
\ [6] T{
Issue an N\(hyRESET response if not already done.
T}
_
.T&
cw(24p) | lw(204p) .
\ [7] T{
See data transfer procedure for the class.
T}
_
.T&
cw(24p) | lw(204p) .
\ [8] T{
Start TTR timer if not already running.
T}
_
.T&
cw(24p) | lw(204p) .
\ [9] T{
Stop TTR timer if running or remove information that TTR timer
has run out (see Notes 1 and 2).
T}
_
.T&
cw(24p) | lw(204p) .
[10] T{
Store information that TTR timer has run out (see Note 1).
T}
_
.T&
cw(24p) | lw(204p) .
[11] Store request.
_
.T&
cw(24p) | lw(204p) .
[12] T{
See state table appropriate to class selected in CC.
\fINote\ 1\fR
\ \(em\ The information is used by predicate P4.
.parag
\fINote\ 2\fR
\ \(em\ This action is not performed if the transport entity is the
responder of if neither reassignment nor resynchronization is in progress.
.parag
\fINote\ 3\fR
\ \(em\ The method of disabling transmission of DT\(hyTPDUs is a local matter. In Class\ 3 for example, it may be effected by setting credit to zero. In
Class\ 1, this may be effected by the setting of a boolean indicator.
.parag
T}
_
.TE
.nr PS 9
.RT
.ad r
\fBTABLEAU A\(hy8/X.224 [T36.224], p.34\fR
.sp 1P
.RT
.ad b
.RT
.LP
.sp 10
.bp
.ce
\fBH.T. [T37.224]\fR
.ce
TABLE\ A\(hy9/X.224
.ce
\fBSpecific notes for classes 1 and 3\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(204p) .
Name Description
_
.T&
cw(24p) | lw(204p) .
\ (1) T{
Any TPDU except DR and CC having an unknown destination
reference.
T}
_
.T&
cw(24p) | lw(204p) .
\ (2) T{
CC TPDU having an unknown destination reference or a mismatched source
reference.
T}
_
.T&
cw(24p) | lw(204p) .
\ (3) T{
CR TPDU which is not duplicated but rejected. If CR TPDU is duplicated,
ignore it.
T}
_
.T&
cw(24p) | lw(204p) .
\ (4) T{
Or send any DT or ED TPDU waiting for transmission or use N\(hyDATA
ACKNOWLEDGE request if available and selected (class\ 1 only).
T}
_
.T&
cw(24p) | lw(204p) .
\ (5) T{
Same as for (9) and issue a T\(hyDISCONNECT indication.
T}
_
.T&
cw(24p) | lw(204p) .
\ (6) T{
If the resultant state is CLOSED, the reference shall be frozen except in the cases described in \(sc\ 6.18.
T}
_
.T&
cw(24p) | lw(204p) .
\ (7) T{
An ER TPDU shall be sent in certain cases (see \(sc\ 6.6).
T}
_
.T&
cw(24p) | lw(204p) .
\ (8) T{
Receipt of a DC TPDU is a protocol error since DC cannot be used for
reassignment. It is suggested to stop the TWR timer\ [5] and to consider
the transport connection as released (CLOSED state).
T}
_
.T&
cw(24p) | lw(204p) .
\ (9) T{
Receipt of one of these TPDUs in this state is a protocol error. It is
suggested to stop the TWR timer\ [5], send a DR TPDU and enter the CLOSING