Unity Express - one way audio problem from local sip trunk

Unanswered Question
Apr 23rd, 2008
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Hi All

Got an inbound sip trunk from Asterisk (yeuck) to uc520 (no config needed on uc520 - inbound sip only). Both devices are on same local subnet.

Calls from * to uc520 work fine until an ext. on uc520 is busy or not answered.

When call goes to Unity - caller (at * end) can hear voicemail message and DTMF tone work but no audio is recorded.

I'm guessing it's an access list problem when * talking to unity - but not sure where to look.

Any ideas?

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anthonyfear Thu, 04/24/2008 - 17:30
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Just thought I`d update:

Problem was traced to access-list preventing traffic from reaching CUE.

Removed access list from CUE interface and viola. Then amended rules and put it back on!

goranpilat Wed, 09/24/2008 - 07:39
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I have the exact same problem except your solution didn't work in my case:(( So just wanted to ask if there are any updates regarding the subject...


goran pilat

jbarcena Wed, 09/24/2008 - 08:46
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One way audio issues are most of the times routing problems.

I recommend you to take a sniffer trace to check which ip addresses are used on the media exchange and then check if you can ping them.

goranpilat Thu, 09/25/2008 - 02:31
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Just a follow-up as I made it work. The external phones in my case were CCM5.1 registered IP phones connected to CME/CUE via SIP trunk. The problem was in this SIP trunk. I had to mark "require media termination point", and "DTMF signaling method" to OOB and RFC2833.

All the default access-lists were acceptable.


goran pilat

slongewa Thu, 09/25/2008 - 13:28
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There's also an issue with 'ip verify unicast reverse-path' that would cause a similar issue with one-way voice traffic. If you're using ip verify unicase reverse-path you may want to remove it and see if this resolves your problem.




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