Solved Avaya CM 5.2 SIP connection - 3CX to Avaya calls intermittent

[GPO]

We plan on migrating from Avaya CM to 3CX gradually and so need to connect the 3CX server to the Avaya via a SIP connection. All the Avaya work has been completed and I can consistently make calls to the 3CX, however the other way around I can only make successful calls occasionally to the Avaya CM extensions.

If I dial a 3CX extension from the Avaya and immediately call an Avaya extension from 3CX, no problem. If I wait a while and then try and call an Avaya extension, nothing, times out, if I try repeatedly I will eventually make a successful call. It does not seem to be based on a fixed parameter, sometimes I need to try 4 times, others it's on the 7th attempt. Time does not seem to be the key either, I've tried calling once, waiting the 40 seconds the last time took and calling again but no joy. On the Avaya a list trace on the trunk group shows no activity received from the 3CX at all. The Avaya is not using the Avaya SIP Enablement Services server but a straight SIP trunk from the Avaya 8720 server in tie mode.

Has anyone successfully got a 3CX to talk to an Avaya Communication Manager (Definity/Aura) 5.2 and if so do you have and config tips?

 

[eddv123]

Avaya IP Office I have via SIP trunks on both system. Done both direct and with VPN's.

 

[JohnS_3CX]

Hi,

Perhaps invites aren't sent, or they are sent and ignored, or they never traversed your network in the first place (for the failed calls). I would first start by checking that invites are sent from 3CX, and whether they were received on the other side. Captures should show you what is happening and can be instrumental in at least pinpointing where to look next

 

[GPO]

Thank you eddv123, I read that a lot, just not the how it was done!

Tracing on the 3CX end just says call cancelled. I'll dig deeper at the packet level but thought it worth asking if someone else with a CM had the same issue, or willing to share what they did for theirs to work.

 

[eddv123]

I have setup notes if you want to PM me. For IP office anyway.

 

[GPO]

Solved.

I've added the prefix "transport-tcp." to the IP address of the Avaya SIP endpoint.
It would seem that 3CX is not consistent in choosing the transport type if left to its own devices.

I'll add that the Avaya IP Office and Avaya Communication Manager have no similarities in operation at all, they are telephony chalk and cheese!

 

[JohnS_3CX]

Hi GPO,

Glad to hear it was resolved, thanks for updating the thread with your solution