Avaya 03-300430 User Manual

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Denial Events
174 Maintenance Procedures for Avaya Communication Manager 3.0, Media Gateways and Servers
 
the far end never saw the message because the message was corrupted in 
transmission by noise on the D-channel. Check for any type of T1/E1 facility errors.
the far end is experiencing a high traffic condition and did not have the processing 
time to parse the sent message before the timer expired. 
even though the message was seen to be generated in an internal Communication 
Manager trace, the message was never transmitted out onto the D-channel. Perform 
an external protocol capture on the D-channel to confirm the transmission of the 
suspect message.
To interpret the receipt of Cause Value 102 from the far end, look at a trace/protocol 
capture of the messaging taking place, and find the last message received from the far end 
before Cause Value 102 is received. The timer that expired is most likely the Layer 3 timer 
associated with that last message. If Communication Manager generated a message in 
between those 2 events that should have stopped the timer, the cause might be:
- the far end never saw the message because the message was corrupted in transmission 
by noise on the D-channel. Check for any type of T1/E1 facility errors.
- the far end might be experiencing a high traffic condition and did not have the processing 
time to parse the sent message before the timer expired. 
- even though the message was seen to be generated in an internal Communication 
Manager trace, the message was never actually transmitted out onto the D-channel. 
Perform an external protocol capture on the D-channel to confirm the transmission of the 
suspect message.
If Communication Manager did not respond to the receipt of the last message from the far 
end, then Communication Manager internal hardware and software becomes suspect, and 
trouble shooting the problem must proceed from that point.
Communication Manager administration that can contribute to seeing timer expiry errors:
Trunk group form: Incoming call handling table. If the Per call CPN/BN field is incorrectly 
populated in comparison to how the CO is programmed to send CPN or BN, it causes 
Communication Manager to send a FACILITY message to the CO requesting CPN/BN 
information and the CO will never respond. Communication Manager will log many timer 
expiry errors against the signaling group (Error Type 1, Aux Data 13).
DS1 form: Protocol version: If Communication Manager is running custom protocol 
(protocol version “A”) and is connected to a Nortel DMS central office running custom 
protocol, Communication Manager will log timer expiry errors against signaling group for 
DISCONNECT problems (Error Type 1, Aux Data 4) during high traffic conditions.
The DMS CO custom protocol implementation uses the ANSI recommended timer values 
for their Layer 3 timers while Communication Manager uses the ITU recommended timer 
values. Thus the T305 timer in the Communication Manager is 4 seconds while the same 
timer in the DMS is 30 seconds, this difference causes timer expiry problems in high traffic 
conditions. Change Communication Manager’s protocol version to c to line up the timers.