No Sound Twinning with Peerless SIP Trunks 4

[chiden]

IP Office 11.0.4.5. Desk Phone 9608. If Relevant
Have setup Peerless SIP trunks in accordance to Avaya Doc.
Everything working great. Routing, Inbound, Outbound.
But when twinning I am getting no audio.
If I interrupt the call I do get audio on Desk Phone. Both ways.
I can then twin/transfer to cell phone and get audio both ways. But on initial twinning no audio either direction.

I've tried tweaking Allow Direct Media Path Settings as well as playing with Mobile Delay and Mobile Answer Guard timers. Hoping maybe something there. To no avail.
I do notice even if I set to delay twin in System Status I see system seize second trunk even before it starts to dial. Not sure if relevant either but something noticed.
Thanks in advance for any assistance.

 

[Ekster]

This is a classic RTP Keepalives problem, the SIP works fine but you get this when you use mobile twinning to SIP, I had the same problem at one of my customers. It is set in the VOIP tab of the LAN interface you use for the SIP trunk.

Set SCOPE to RTP
Set PERIODIC TIMEOUT to (try different settings I started at 10 seconds and worked my way down)
Set INITIAL KEEPALIVES to ENABLE

“Some humans would do anything to see if it was possible to do it.
If you put a large switch in some cave somewhere, with a sign on it saying 'End-of-the-World Switch. PLEASE DO NOT TOUCH'.
The paint wouldn't even have time to dry.”

Terry Pratchet

 

[chiden]

Thanks for reply Ekster.
It was set for RTP-RTCP Timeout 30 and Enabled.
Changed to just RTP. Played with timeout from 10 down to 1.
Unfortunately still had same issue. No sound if doing twinning.

Really appreciate you taking time to reply.

 

[MrFooF]

Hello,

I got the same issue.
Provider didn't like to reroute voice to an other destination.
What I found is using different codecs for incomming and outgoing communications.
Then, the IP Office has to stay in the path.

Ask provider to accept G711 A-law AND U-Law codecs (G729 is ok, but, quality... )

Codec order in system :
G711A
G711U

Codec order in Sip line :
G711U
G711A

Solved the issue for me.

 

[chiden]

So got this resolved.
Used variation of what MrFoof recommended. Thank you sir.

Carrier couldn't understand my request so took variant path.
Took Original SIP line. Copied and Pasted into Second SIP line.
Then went into Original SIP line. Set for Inbound Only. Set Codec to G.711U
Went into Second SIP Line. Set for Outbound Only. Set Codec to G.729 (Carrier doesn't support G711A)
So calls come into Original SIP Line as G.711U but then twin out on Second SIP line as G.729. Voila. Have Audio.

And so you know. Having them both at G.711U did not provide audio. Had to have different Codecs.

So far so good!!! I'm going to go have a bourbon.