delay in audio on inbound calls

[sdwitner1]

I have a 2811 voice gateway with Cisco 7942 phones behind it that is getting voice delivered to it via SIP trunks. When an inbound call comes in the office personnel will answer the call and have about a 10 second delay before hearing the caller. The caller can hear the office saying hello several times before the two way audio is established.

this is my inbound dial peer:

dial-peer voice 100 voip

description inbound from GC

rtp payload-type nse 105

rtp payload type nte 100

voice-class codec 1

voice-class sip early-offer forced

session protocol sipv2

incoming called-number ..........$

dtmf-relay trp-nte

fax protocol pass-through g711ulaw

no vad

[paolo bevilacqua]

Do you have any firewall between the 2811 and the Internet ?

[sdwitner1]

We do, but this is the only location out of a dozen that have this issue. I would think that if it was a firewall issue that it would be more wide spread. The internet access for all our locations comes back to our corporate office.

[paolo bevilacqua]

Understand, but I would still look for a proof that the router is receiving RTP in the first 10 seconds, before blaming it.

Not the easist job, maybe you can use some ACL for the purpose.

[sdwitner1]

Attached is a “ccsip messages” debug of a call with the delayed audio on an incoming call.

[paolo bevilacqua]

Unfortunately that type of debug cannot show if router is receving RTP packets in the first 10 seconds, or not.