Audio Delays

[mrmac]

We have some 900s deployed behind a Calix ONT which is connected to a MetaSwitch VP-3510 IS.  We have only recently begun to deploy this configuration and we have a subscriber with several lines within a hunt group.  When you call this sub you hear the normal audible ringback and the callee hears their phone ring.  The callee then answers the call but doesn't hear anything until a couple of seconds later.  It seems as though the RTP stream doesn't start immediately.  From the subscriber end, they answer the call with their business name and then have to repeat it when they start to hear background noise from the caller.

I sent a call trace to MS and we all see a SIP 491 come back from the 900 after it tries the second line in the hunt group.

Has anyone else seen this kind of behavior before and, if so, how did you deal with it?

[Anonymous]

Mrmac,

I don't see anything in your configuration that should cause the SIP 491 to be sent from the Adtran unit.  The RTP packet duration and delay settings are not something we typically see set that way, but I do not see why that would cause the issue.  You may need to call 888-423-8726 and create a normal support queue ticket so that we can log into the unit and capture the debug output.  The first thing we will check is the status of each of the FXS ports and then run the following for a test call.

debug sip stack message

debug voice verbose

debug interface fxs

That should give us information about why the 491 is sent out.

Thanks!

David

[Anonymous]

Mrmac,

I thought I would check back in with you to see if you had made any progress on this issue.  Please let us know if you worked this issue with a Technical Support ticket, or found some other resolution.  Otherwise, just let me know if we can be of further assistance.

Thanks!

David

[Anonymous]

Mrmac,

I went ahead and flagged this post as "Assumed Answered".  If the response on this thread assisted you, please mark it as Correct or Helpful as the case may be with the applicable buttons.  This will make it visible and help other members of the community find solutions more easily.  If you still need assistance, I would be more than happy to continue working with you on this - just let me know in a reply.

Thanks!

David