ONE WAY VOICE ISSUE Please help !!!!!

[Rohit Mangotra]

Hello Experts,

We have one central site and several remote sites. At central Data Centre site has a Subscriber and a SIP2 voice router. Our CUCM Publisher and SIP1 voice router are at Civic centre remote site. Both Data Centre and Civic remote site are linked with  500 MB leased line (fibre optic). We also have several VPN remote sites. The VPN remote sites connect to our Data Centre via broadband networks through our ASA 5520 firewall-VPN gateway.

Currently, all IP Phones (7912, 7945) at one of our VPN remote site experiences one-way voice issue for external incoming call. This VPN remote site connects through our Data Centre via NBN network.

After several troubleshooting, we identified that the one-way voice issue only occur with external incoming call ONLY and the external incoming call come through SIP2.

If the external incoming call come through SIP1 (Data Centre) then there is NO one-way voice issue occur.

Note: One-way voice issue means our IP Phone cannot hear the other party but the other party can hear our audio/voice.

Please see attachment files (captured voice signal of normal and one-way voice).

Thank You,

Kind Regards

[Elliot Dierksen · Accepted solution]

99 times out of 100, one way audio is a routing problem. It certainly sounds like that in your case. Specifically, the SIP2 device cannot reach the IP address of the IP phone in question. Can SIP 2 ping one of the remote phones? You might be able to mitigate that by forcing an MTP on one of the call managers (assuming the call managers can reach SIP and the remote phones).

[Rohit Mangotra]

Hi Elliot,

I have managed to fix the issue. You were right most of the times, it is because of the routing issue. In my case there was an issue with the ip addressing. Changing the ip address fixed the problem.

Thank You,

Kind Regards