16 sec delay on calls, PBX integration t1 E&M

[Mamdouh Elgamal]

Hello, running into the following issue and i'm having a hard time narrowing down the problem.

Trying to centralize call flow for a number of sites, we ran into an issue when we re routed calls through CUCM

Orginal Topology:

Avaya PBX --> T1 E&M --> 2811 router SIP GW --> SIP Verizon PSTN

New Topology:

Avaya PBX --> T1 E&M --> 2811 router --> SIP --> CUCM 8.6 --> CUBE --> SIP Verizon PSTN

whenever i make a call from the PBX side, i get 16 secs of delay before ring back. I have another site that's identical to this setup with no issues whatsoever.

i attached GW configs and also gateway debugs from a test call

CUCM IP address is 10.1.40.102

SIP gateway is 10.80.40.40

CUBE IP is 10.40.40.10

calling number is 415 538 8000

called number is 248 787 8187

any input is appreciated

Thanks

[George Thomas]

Without looking at all the debugs attached, 16 seconds to me seems like the default T302 interdigit timer plus a second for call setup. Have you looked at this parameter? Do you happen to have overlapping dial plan in CUCM?

Please rate useful posts.

[Mamdouh Elgamal]

I have t302 timer set to 6 sec and i've tested it and seen it work as intended. Since the PBX uses CUCM to access the PSTN. I tried creating fixed pattern

i.e 91[2-9]XXXXXXXXX vs 9.@

but still no luck with eliminating the delay.

I rand dial peer debugs and there is not issues with the dial peers, esp that this CUBE is being utilized by other PBX sites with completely different dial plans

Thanks

[Suresh Subramanian · Accepted solution]

Hello Mando,

The PBX is sending the called number digit by digit (912487878187) to GW. The outbound dial-peer (dial-peer voice 20 voip) has the destination-pattern 9T. The 'T' terminator forces the router or gateway to wait until the full dial-string is received.

It routes the call once the device receives the "#" termination character in the dial-string.

Please try dialing 912487878187# and check the behavior. Also you can reduce the interdigit timer under voiceport config.

http://www.cisco.com/en/US/docs/ios/voice/command/reference/vr_t2.html#wp1640664

Also, you can force the PBX to send the complete set of called number instead of digit by digit.

[Mamdouh Elgamal]

I've made changes to the dial peers on the 2811 router to be a fixed lenght

i.e 91[2-9].........$ and

     9[2-9].........$

i also set the inter-digit time out on the voice port to 4 secs

these changes reduced my delay from 16 sec to now around 4-6 secs

when i hit # at the end, doesnt make it any faster

Happy with it, issue resolved. Thanks guys