SIP to SIP calls over VPN one way audio

[Patrick McHenry]

Hi,

has anyone had an issue with one way audio of SIP phone to SIP phone communication over VPN?

SIP to SCCP over the VPN is fine.

The VPN is used as a backup circuit. When communication is over the MPLS circuit SIP to SIP is fine, but not over the VPN.

We are not blocking any IP communication between sites so I'm confused as to what might be causing the failure.

Thank you

[Dennis Mink]

Patrick, issues like this have been raised dozens of time on this forum.  Have you checked one way audio posts on this forum yet?

[Patrick McHenry]

Thanks Dennis

Yeah I looked, but nothing seems to fit my situation very closely. Especially over VPN

[Mohammed al Baqari]

Hi,

Most probably this is a routing problem. Use the command show voip rtp conn during active call to find out the IPs of the endpoints and then try to ping between them over VPN. If this isn't happening then you need to look at your routing, firewall, natting policies.

[Patrick McHenry]

Thanks Mohammed,

Routing is fine as all other data traffic and specifically SIP to SCCP calls work fine. On which device would I use the "show voip rtp conn"?

Thanks