Outbound SIP call disconnects after 30 seconds

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Sep 7th, 2010
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We have a SIP implementation that is working for the most part with no problems.

It has been in place for a while with no problems.

Recently we ported some local numbers to allow them to also use the SIP trunk, we have discovered that when calling a particular company local to us, with an especially long attendant message, the call disconnects after 30 seconds.

During the call and the company's openeing message, there are no prompts prior to the disconnect.

Calling from Cell does not exibit this problem.

Doing a "debug ccsip event" shows the following at termination, the BYE sip [email protected], is my extension and our CUBE router.

"Debug ccsip error" did not really show me anythigng that looked related.

083821: .Sep  7 15:12:30.012 EDT: //-1/xxxxxxxxxxxx/SIP/Msg/ccsipDisplayMsg:
BYE sip:[email protected]:5060 SIP/2.0
Via: SIP/2.0/UDP;branch=z9hG4bK9itbu7200gcgsn0ps1i0sdmhjpk50.1
From: <sip:[email protected]>;tag=1369187014-1283886719404
To: <sip:[email protected]>;tag=AA5466D4-25BA
Call-ID: [email protected]
CSeq: 919489547 BYE
Max-Forwards: 69
Content-Length: 0

In order to troubleshoot the SIP call, is "event" the best tag to use?

With BYE message, is that my gateway terminating the message, or did it get received from the remote end?

Is there potentially a timeout happenign that would disconnect he SIP call with no input from the user?

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Overall Rating: 5 (3 ratings)
ADAM CRISP Tue, 09/07/2010 - 13:47
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Calls cutting off after 32 seconds are indicative of a SIP dialogue problem, where something hasn't been acknowledged properly.

There's a round trip timer timer called the T1 timer (normally 500ms) and the timeout is after 64 intervals, i.e. 64 * 500ms = 32 seconds.

Is there a possibility that the company you are calling is also a customer of the same service provider ? If so, gather SIP traces (debug ccsip messages) of a working call to a working number, and of a call to the problem company and send them to your service provider for help. I'm guessing that you're seeing a dialogue problem between your cube and the PBX of the problem company. The SP might be able to tweak something on their sbc to fix the incompatibility. You could also try enabling some of the address hiding features (and B2BUA) on your cube, which could make signalling simpler between the hops, and make the dialogue less end-to-end.


Christopher Graham Tue, 09/07/2010 - 15:51
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It also looks like the BYE is coming from the other side of the SIP leg:

BYE sip:[email protected]:5060 SIP/2.0

We could tell a bit more with:

debug ccsip all

debug voip ccapi inout

wilson_1234_2 Wed, 09/08/2010 - 05:11
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What would I be looking for with the debugs suggested?

Also, is there a way to isolate this one call from all call activity in the debugs?

ADAM CRISP Fri, 09/10/2010 - 01:17
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I know it's difficult to find a quiet time, to gather the trace when there's just your test call going on, but if you could gather the output of a debug ccsip messages of a working and and a broken call i'll try and step through it with you and explain as we go.

We have at least three call legs here

1. cm to cube

2. cube to sp

3. sp to third party

4. etc

obviously we can only see the output on your side, you previously posted a BYE message, which is for sure, something terminating a dialogue branch. it may be that the problem lies between the SP and the third party.


wilson_1234_2 Fri, 09/10/2010 - 05:53
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What a generous offer Adam, thanks.

There is no quiet time really, but I will see what I can get.

I was thinking that since it has only been reported from the one company that it was something on their end.

Also, the greeting message is so long before requesting input.

When I try to get a response during the gretting message, I get no response from the other end.

I will upsdate when I can get some info.

Also, when calling their fax number, the call does not disconnect.


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