Lucent Technologies Comcode 108678723 manual Unusual ATM trouble conditions, Action

DEFINITY ECS Release 8.2 ATM Installation,	Issue 1
Upgrades, and Administration 555-233-124	April 2000
6 Troubleshooting
Troubleshooting ATM-CES	6-15

—These virtual circuits may persist beyond the duration of a phone call. The DEFINITY Call Processing software saves virtual circuits for a few seconds after the end stations have hung up in case the VC can be used again for another call between the same two port networks.

—There may be other CBR virtual circuits between ATM switch ports that are not associated with DEFINITY port networks. A common CBR application is Circuit Emulation, in which T-1, T-3, and so forth circuits are carried over ATM.

Unusual ATM trouble conditions

A few failure modes in the DEFINITY ECS/ATM switch combination are particularly difficult to diagnose. One example might be that you cannot make a completely successful call even though most indications from DEFINITY ECS and the ATM switch look good.

This section documents some hints and clues that may help diagnose the following failure modes:

■Incorrectly typed or omitted EPN route or end system identifier (ATM switch)

■Swapped routes, end system identifiers, or fiber between a PPN and an

EPN

Incorrectly typed or omitted EPN route or end system identifier (ATM switch)

Symptoms

Talk paths are one-way, from the PPN to the EPN: you can hear tones from the PPN end station to the EPN end station but not vice versa. Because the signaling channels are bidirectional virtual circuits (VCs) established from the PPN to the EPN, these can be routed correctly and come up just fine. Talk paths are two unidirectional virtual circuits, so a single call has one VC from the PPN to the EPN (which is routed correctly) and one VC from the EPN to the PPN (which cannot be routed).

Diagnostics

1.At the ATM switch, check the ATM addresses.

2.Look for a cause code 3 (No route to destination).

Action

1. Correct the ATM address translations in the ATM switch.