Unity VM's From Outside Are Getting Cut-Off

[droessler]

I have Unity VM length set to 180 seconds for all subscribers. Internally IP Phone to IP Phone, it works fine - messages are ended when if 180 second mark is reached. However, when external callers leave VM they always get cut off at 1 minute. Any ideas why this is happening?

[droessler]

UPDATE:

calling in on or T1 CAS (which is configured as H323) the VMs do not get cuttoff/dropped - we can leave a message that lasts the full 180 seconds. When calling in on our POTS lines (all configured as MGCP) VMs get cutoff/dropped at about 40 seconds everytime.

Looks like it isnt a Unity issue, but perhaps a CM or MGCP bug.... Any Ideas???

[alan.basinger]

I am seeing the same issue with UNITY 3.02 and my 2610 with 2 FXO's configured as MGCP. In my case it is less than 5 seconds. I have not found anything on TAC's web site and in Unity class no one had never heard of this issue. I think I will try a different version of code on the 2600 router.

[droessler]

We fixed it. MGCP has a default timeout of 40secs if there is no voice traffic over the gateway. We added the "no mgcp timer receive-rtcp" and it has fixed the problem.

[dugrant]

Just to clarify - it isnt that the gateway hasnt received voice traffic, it is because it hasn't received RTCP packets from the remote end.

RTCP (or Real Time Control Protocol) is used between endpoints to report on packet loss, jitter, etc.

IP phones and Unity ports do currently not send RTCP reports. When this timer pops, the call will be disconnected.

-Dustin