home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Internet Standards
/
CD2.mdf
/
ccitt
/
1992
/
r
/
r115a.asc
< prev
next >
Wrap
Text File
|
1991-12-31
|
3KB
|
103 lines
1)Replace Figure 1/R.115 by the following:
FIGURE 1/R.115 A RECUPERER
2) Replace existing paragraphs 3.5 and 3.6 by the following:
"3.5 Loop f - tributary analogue loop
This loop is a one-way loop (see Figure 2/R.115). With this loop, the
tributary signal to be sent to the subscriber is looped back towards the multiplex
system. This loop shall be accomplished at the subscriber line interface and
shall include as many parts of the tributary interface unit as possible. As long
as the loop is set the subscriber connection is interrupted.
3.6 Loop g - tributary digital loop towards the MULDEX
This loop is a one-way loop (see Figure 2/R.115) with the output polarity
towards the tributary interface unit strappable to A or Z polarity. Through this
loop the channel data as received from the aggregate is looped back to the aggre-
gate towards the distant TDM equipment. This loop shall be accomplished as close
as possible to the internal tributary interface which can be located on the
tributary interface unit or in the TDM central logic.
3.7 Loop h - tributary digital loop towards the tributary interface unit
This loop is a one-way loop with the output polarity towards the MULDEX-
part of the given channel strappable to A or Z polarity. Through this loop the
channel data at the tributary input is looped back to the channel output through
the tributary interface unit. This loop shall be accomplished as close as possible
to the TDM central logic."
3. Modify 5.3 as follows:
5.3 The control of loops a, b, c and d should be supervised by a time-out
function. The time-out function shall automatically open the loop after a
specified time period, measured from the closing of the loop. The length of the
time period should be chosen from time intervals 5, 20 or 40 seconds by bilateral
agreement between administrations.
The operation and test procedure for loop f to h is a national matter.
4. Modify 6.2 as follows:
6.2 Alternative B
When maintenance facilities do not use control signal according to
Recommendation U.12, the signalling characters on the maintenance channel selected
must conform to International Alphabet No.5 (IA5), with an even parity check
(Figure 6/R.115).
FIGURE 6/R.115
Control signalling format