[OpenSIPS-Users] Calling MediaProxy twice for same call results in no voice

Saúl Ibarra Corretgé saul at ag-projects.com
Fri Jun 8 13:50:08 CEST 2012


On Jun 8, 2012, at 11:53 AM, Jayesh Nambiar wrote:

> Hi All,
> I have a following scenario:
> 1) I have one opensips proxy(proxy1) where sip endpoints register and sends calls to.
> 2) The calls from proxy1 is sent to another opensips proxy(proxy2) which routes calls to PSTN carriers.
> 3) Both the proxy1 and proxy2 have mediaproxy module loaded and the dispatcher on each server is connected to the same media-relay(Relay1).
> The problem is here:
> 1) When a call comes to Proxy1, I call engage_media_proxy. This allocates media ports from Relay1 and sends the call to Proxy2 for call completion.
> 2) Now the Proxy2 is again calling engage_media_proxy, since the Proxy2 is configured in such a way that it calls engage_media_relay for every call signaled through it.
> 3) Now since the Proxy2 is also configured to use the same media-relay that Proxy1 was using, the Relay1 allocates media ports for same call from the same media-relay again.
> 4) Theoretically, I assumed that this should work but it results in No Audio on both ends.
> 5) But, When I enabled a condition in Proxy2 which says that if the call is initiated from Proxy1, don't call "engage_media_proxy", the voice is good and both parties can hear.
> I understand that it is not right to call media_proxy twice for the same call even if it is from different opensips proxies, I am only curios to know what goes wrong in this scenario.
> These are two different opensips calling "engage_media_proxy", so why and where does the mediaproxy get confused??
> Any ideas in making me understand this concept will be very helpful !!

Even if they are different proxy instances, the call identifiers are the same: call-id, from-tag, to-tag and so on. The relay will be instructed to update the data from the session by both proxies, not a good thing.

Since you probably need to do NAT traversal between users as well I'd remove the NAT traversal handling from proxy2 and keep it just on proxy1.


Saúl Ibarra Corretgé
AG Projects

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