[OpenSIPS-Users] Parallel forking (using registrar branching) & mediaproxy

[Ruud Klaver]

Hi Erwan,

On 04 Jun 2009, at 12:09, erwan.humez at orange-ftgroup.com wrote:

>
> Hi,
>
> I came across something weird about parallel forking: media  
> information (IP @ received from SDP for RTP) is not properly  
> communicated to media proxy, but only for one of the 2 calls.
>
> Here is the context :
> opensips 1.5.1 / mediaproxy 2.3.4 / Centos 5.2, on IP 192.168.2.233
> Caller on sip softphone, on IP 192.168.2.223
> Called on 2 tdm cisco media gateways, each registered using the same  
> uri 8003 at 192.168.2.233 behind 2 different IP@ : 10.0.0.2 and 10.0.1.1.
> Objective is to achieve a call // forked from sip to both tdm called  
> parties.
>
> // sip forking seems to be working fine in the way that when one  
> picks up the other one is properly cancelled. For information, both  
> media gateways send a 183/SDP message and then a 200 OK/SDP upon  
> pick-up. Media proxy sends/forwards 183/SDP messages to caller  
> without modifying IP @ (keeping 10.0.0.2 & 10.0.1.1) and then only  
> sends the modified (with media proxy IP@) 200 OK/SDP message to the  
> caller upon pick-up.
>
> The issue (check below for media proxy traces) is reproductible  
> because each time the same gateway is impacted (no need to precise  
> that basic calls are working fine in both ways for call setup and on  
> both gateways, which should prevent from any network related issue/ 
> question).
>
> Of course i got all required traces that i can provide upon request  
> to avoid spamming the list but so far and mainly, here is what i can  
> see from media proxy traces:
>
> Working call:
>
> debug: Got traffic information for stream: (audio)  
> 192.168.2.223:5298 (RTP: 192.168.2.223:5298, RTCP:  
> 192.168.2.223:5299) <-> 192.168.2.233:50072 <-> 192.168.2.233:50074  
> <-> 10.0.0.2:19098 (RTP: 10.0.0.2:19098, RTCP: 10.0.1.1:19163)
>
> => RTCP IP is not correct here but does not prevent the call to be  
> successfully established.
>
> Non-working call:
>
> debug: Got traffic information for stream: (audio)  
> 192.168.2.223:5304 (RTP: 192.168.2.223:5304, RTCP:  
> 192.168.2.223:5305) <-> 192.168.2.233:50080 <-> 192.168.2.233:50082  
> <-> 10.0.1.1:16910 (RTP: 10.0.0.2:19560, RTCP: 10.0.0.2:19561)
>
> => RTP 10.0.0.2:19560 information is taken from the 183/SDP message  
> sent by the gateway to wich the forked call is canceled: it should  
> be the RTP information coming from the 183/SDP message sent by the  
> other gateway (10.0.0.1:16910).
> => neither RTP and RTCP are correct here. Network traces confirm  
> that media proxy keeps sending RTP packets towards 10.0.0.2:19560  
> getting an icmp destination port unreachable of course.
>
> I understand that SDP information received in both 183 messages  
> could cause some troubles in opensips and media proxy  
> communications... Somewhere and somehow, the information should be  
> updated in media proxy...
>
> ... but maybe i missed or misunderstood something, so please can  
> someone enlight me on this issue ?
>
> Thanks a lot for help and support,
>
> Erwan.

I don't think I fully understand your scenario and what exactly is  
happening here. One issue could be that MediaProxy was never designed  
to operate using a private IP address. Could you please provide be  
with full logs from both the relay and the dispatcher?

Ruud Klaver
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