Cisco ASA 5585 RTP traffic inspection

paredesh · ‎09-26-2017

Hello -

We have company that has 2 sites, each are network independent of each other. One in India and the other in the states. There is a circuit between the 2 companies that already carries some traffic (http) and it is working. We are trying to set up a SIP Trunk between the 2 cisco call managers. There is a NAT in place which lets the call come in and when it is picked up on the other end there is no sound. After troubleshooting / and doing captures we notice the RTP traffic is getting addressed to the original ip address of the 2 phones (ip address in India and US) that are part of the call as it should. Obviously these 2 ip addresses are not part of the NAT. Is there a way the Cisco ASA 5585 ver 9.6(2) inspect that traffic?

Flavio Miranda · ‎09-27-2017

Hello,

Are you inspecting sip on ASA ?

Another issue I faced was with RTP problem in the past and the problem was that RTP takes the local device´IP to mount the source IP and this IP goes to the other side. However, the other side try to reply to that local IP address and fail.

I saw here in the forum a very detailed tutorial about this issue. This may help you.

https://supportforums.cisco.com/t5/collaboration-voice-and-video/how-to-troubleshoot-one-way-no-audio-issues/ta-p/3164442