[SR-Users] rtpproxy_offer and fix_nated_sdp in one route

Richard Fuchs rfuchs at sipwise.com
Mon Sep 29 18:58:32 CEST 2014


On 09/24/14 09:16, Sebastian Damm wrote:
> Hi,
> 
> I switched from rtpproxy module to the rtpproxy-ng module lately, and
> noticed a strange behavior. In my branch route to the device, I have two
> statements:
> 
> fix_nated_sdp("1");
> rtpproxy_offer();
> 
> The first command appends a line with "direction:active" to the SDP. The
> second one puts the RTP proxy in the stream. This worked all well with
> the old rtpproxy module. But with the new rtpproxy-ng module, I get an
> empty line after the SDP body, just before the "direction:active" line
> in the SDP, which makes the packet invalid.
> 
> I tried changing the order of both statements, but without any
> difference. What I saw is, that the old module just sent some basic
> parameters to the rtpproxy and got only IP and port back. The new module
> sends the complete SDP to the rtpengine and gets back the "fixed" SDP.
> 
> Has anyone ever seen this? Is there a way to fix it?

This is caused by rewriting the SDP body twice. The rtpproxy module only
rewrites small parts of the SDP, while rtpproxy-ng substitutes the
entire SDP body, which is why you run into conflicts when there's
another function touching the SDP body. Calling msg_apply_changes()
between the two calls fixes that, but may have side effects. I would
suggest the same as Juha did.

cheers



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