[Freeswitch-users] Can it do it?

[JuanMa]

Hi,

I need to have the hability to negotiate the codec in a session (using  
proxy media or bypass media), unfortunally I've been unable to achive  
this due the documentation that I've found about it's vague.

I've already tried using "absolute_codec_string" and everything that  
says in http://wiki.freeswitch.org/wiki/Codec_negotiation but it seams  
to ignore it  when the media is in "bypass media" or "proxy media". I  
need to configure the FS as a SBC or as a pseudo proxy (I already know  
that FS is not intend to do it, but in the documentation says that it  
can).

I've also tried to manually modify the SDP using:
  <param name="inbound-late-negotiation" value="true"/>

And updating variables "switch_r_sdp" and "switch_l_dsp" but it also  
seams to ignore it.

Here is the config:

Endpoint1-->FS-->SWITCH-->FS-->Endpoint2

What I need, is to offer to the SWITCH only the codecs defined for  
Enpoint1 (ie. G729) and when the SWITCH send the INVITE to FS again,  
only offer the codecs available for Endpoint2. Eventually the SWITCH  
will do the transcoding.

So, here is my question, is there any way to achive this? (Handle the  
invite codecs in bypass or proxy media), if so, is there any example  
to follow? o can you give a tip?

Thanks in advance,
Regards