Audio trimmed in recording

[Jose Lopez]

Has someone had this issue before?

The silent part is trimmed on the call recording, which happens when I use a specific Voice Gw.

I have 3 Cisco Routers (voice gateways) the issue is just with one of them

Jabber -- CUCM ---trunk----Recorder server

[Jonathan Schulenberg · Accepted solution]

What’s different - version, circuits, config, etc. - between the working and non-working voice gateways?

What does a PCAP look like? Are the RTP packets sent by the gateway to the recording server during that silence?

My only speculative guess would be Voice Activity Detection but that’s super rare. I’m not even certain it would manifest as this symptom.

[Jose Lopez]

Hello Jonathan,

The configuration of one of them (functional) is the same unlike the IPs, both use SIP towards the CUCM and ISDN towards the service provider, The difference is that they are located in different networks (branches), I have already compared the SIP Trunk configuration to the CUCM and both are the same, the service provider for the recorder says that the packets do not arrive in order at the server.
However, when I do the packet capture with Wireshark on the server, the call is heard correctly.

Thank you

[Jonathan Schulenberg]

Wireshark can reorder the RTP packets in the capture using sequence numbers so they play correctly; that's not a reliable indicator. (Arguably a recording server could as well.) I believe that RTP stream analysis will show when packets arrived out of order though, if you're looking to test that assertion.

[Jose Lopez]

You gave me a good clue (Voice Activity Detection).
Although Voice Activity Detection is disabled on all dial-peers (not vad) and incoming called-number is configured, it seems that this router omits this configuration, What I did is add "voice vad-time 30000" on global configuration then the calls started to record right.