TR: [Serusers] rtpproxy general questions

[Christian de Balorre]

Thanks very much, very valuable info indeed.
I have a few questions that must have been asked a thousand times but I did not find any clear answer in archive :
Or can you point me to relevant doc ?

1) fix_nated_sdp :
- I guess you use this fonction if you want a nated ua to talk directly to another ua w/o rtproxy ?
- what is exactly the sdp field modified ? c ? o ?
- is it relevant if you use force_rtp_proxy ? (my guess is no...)

2) force_rport()
- Could not figure out the usefulness of this command... Deprecated by fix_nated_contact ?

3)force_rtp_proxy 'f' flag
-I really cannot figure out what it does (or does not!)  on a sip packet. I would just blindly use it but I would like to understand nonetheless :-)

Also I would need an advice :

You often see this portion of code at the beginning of a "main routing logic" config file :

        record_route();
        # loose-route processing
        if (loose_route()) {
                t_relay();
                break;

If I am correct it says "if this packet as already been processed by a sip proxy, route it accordingly".
But suppose a sip INVITE packet went through a first Proxy, then it will be routed back instead of being correctly processed with lookup("location") for exemple.

Would 
        if ( !(method=="INVITE")) {
        if (loose_route()) { t_relay(); break; };

be more appropriate in this case ?


Thanks for your patience  -

Christian 


-----Message d'origine-----
De : Marian Dumitru [mailto:marian.dumitru at voice-sistem.ro]
Envoyé : jeudi 3 février 2005 21:34
À : Christian de Balorre
Cc : serusers at lists.iptel.org
Objet : Re: [Serusers] rtpproxy mess


Hi Christian,

To configure rtpproxy to do bridging, just set the listen parameter as 
"-l addr1/addr2". In your configuration I guess addr1 is the private 
address and addr2 is the public one.

But be careful about using a chain of rtpproxy - you can end having a 
dead-lock for the media relaying. More information about the 
force_rtp_proxy flags can be found in modules/nathelper/nathelper.c at 
the beginning; also take a look at the example 
modules/nathelper/examples/alg.cfg.

Best regards,
Marian


Christian de Balorre wrote:
> Thanks for your previous rtpproxy workaround.
> 
> Here is actually what I want to do (not really extraordinary, inter-sites
> design) :
> 
> 
>  __ priv net    __     pub net        __   priv net         __
> |__|<------->|__|<------------>|__|<------------>|__|
>  ua1                rtp                      rtp                        ua2
>  site1              proxy1                proxy2                  site 2
> 
> rtp stream should always flow between ua1 et ua2 through rtpproxy1 and
> rtpproxy2 (or vice versa of course)
> each rtp server is also a ser server with 2 interface, one in priv net and
> the other in pub net
> there is no nat involved
> 
> I guess we can call this bridging... Can rtpproxy do that ?
>