Table of Contents
Advertisement
3-4 D-channel handler
To run the continuity test, perform the following steps.
1 Go to the PRADCH level of the MAP terminal. The full path name is:
2 Enter the POST command to post the DCH associated with the DS-1 to
3 Ensure the D-channel is looped back at the far end. To do so, use the
4 Enter the CONT command with the external (EXT) option to run the
5 At the far end, remove the loopback with the LOOPBK REMOVE
Troubleshooting
Check the following if the DCH is in lockout (LO):
Also refer to "Restoring service to the DCH," in Chapter 10, "Service
verification."
Test equipment
A protocol analyzer can be used to monitor a DS-1 channel. Analyzers are
normally used to check layer 1. However, analyzers can be used to check
whether layer 2 HDLC flags are being transmitted. HDLC flags must be
transmitted from both sides of the DS-1 channel when operating at a rate of
64 kbit/s. This check can be made after the DCHs are ready for service.
297-2521-106 Standard 23.01 March 2001
MAPCI;MTC;TRKS;TTP;PRADCH
test.
LOOPBK SET command at the far-end switch.
external continuity test.
command.
Baud rate (field DCHRATE)—datafilled at the local end (in Table
TRKSGRP) may not match that at the far end of the DS-1 channel.
NETWORK setting—The DMS-250 switch is considered to be the
network in the layer 2 protocol. This means that entry IFCLASS in Table
TRKSGRP must be set to NETWORK. Other datafill may cause LO.
DS-1 channel configuration—If local parameter IFCLASS in Table
TRKSGRP is set to USER, verify the remote DS-1 channel
configuration.
Appropriate card type—The DS-1 channel may not be supervised by the
appropriate NT6X50 DS-1 card type.
Layer 1 setup—may be set up incorrectly. Both sides of the DS-1
channel may not be set for the same frame format (either standard or
extended).
Frame synchronization—The DCH does not send any messages to the
far end unless it has frame synchronization with the far end. Use a
protocol analyzer to verify frame synchronization.
Advertisement
Table of Contents
