12-27-2013 01:37 PM - edited 03-16-2019 09:01 PM
Hey All,
Previously we had integration to a Nortel CS2100 working great via a SIP trunk.
Recently we had to upgrade the Nortel to SE16 and since then I have been having an issue with the following call flow.
1. Call originates from Cisco IP(SIP) phone to a Nortel TDM phone over the SIP trunk and if that TDM phone hunts to VM I get dead air for 11 seconds then the call drops. If the TDM phone is hard forwarded into VM then their is no issue, it is only when it hunts.
- I mentioned Cisco IP(SIP) above because it does not drop if it is from a SCCP phone like a 7925 WIFI phone or a soft client like IP communicator or even the SIP trunk I have for Microsoft Lync.
In looking at logs on RTMT I am now seeing re-invite inside a re-invite error(in red below) messages which you can see in the screenshot below (sorry for the blackout but infosec policy required it) . Anyone have any ideas? I do have a TAC case open but I am really trying to get this fixed before everyone comes back from the holiday.
12-27-2013 02:03 PM
What does the full SIP message exchange look like?
12-30-2013 10:07 AM
Here is a SIP call trace of a failed call from TranslatorX..
12-30-2013 11:12 AM
Andrew,
So the issue here is CUCM and the Nortel system are both trying to Re-invite at the exact same time. If you have SDI/SDL traces, I could take a look at what is triggering the Re-invite on the CUCM side.
Brian
12-30-2013 12:17 PM
Hi Brian,
I just sent you a PM .
Thanks!
12-30-2013 02:06 PM
Just wanted to update everyone on here with the details I found in the traces. CUCM was doing Early Offer to the Nortel side and the 200OK from Nortel still had 2 codecs listed rather than one causing CUCM to immediately Re-Invite with G./711ulaw only. It looks like the Nortel system doesn't know how to handle inbound early offer. Solution will be to turn off Early Offer on the CUCM SIP Profile.
12-30-2013 02:09 PM
Brian has really been amazing with this issue.
Tomorrow I will create a new SIP profile and temp point my SIP trunk to that to see if it makes a difference once I do some testing I'll post the findings here.
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