[Serusers] ser-rtpproxy bridge mode and T38

Greger V. Teigre greger at teigre.com
Thu Oct 27 09:16:01 CEST 2005


>> > I have raised this issue in dev list but got no response, hoping some
>> > one here will be able to answer this.
>> >
>> > I have read in RtpProxy that RtpProxy waits for both parties to send
>> > atleast one udp packet and then it fills up both ip:port structures
>> > associated with that call and then it starts relaying.
>>
>> Yes, this is to ensure that the proxy can get through the NATs.
>>
>> > Call Setup is like this:
>> >                --------Media----->
>> > A-Party ----->MG-------->SSW------>SER/RtpProxy------->B-Party
>> >
>> > now only B-Party is sending UDP Packets and Ser/RtpProxy sends them to
>> > SSW (signalling entity) instead of MediaGateway. As soon as RtpProxy
>> > receives one udp packet from A-Party then it sends those RTP packets to
>> > MG i.e. it starts relaying following the right path.
>> > how I can solve this ???
>>
>> I'm afraid I'm not capable of understanding what you are saying here. 
>> You
>> have SSW in the media path? Or are you trying to show both media and
>> signalling path in the same picture? What is really the priblem? rtpproxy
>> will only do what you tell it to (using force_rtp_proxy).
>
> I am trying to show media and signalling path in the same picture.

I'm sure you understand that it is difficult for others to understand?

> Is this confirm that RtpProxy will handle T38 or we also need to handle
> T38 in a special way. because as I described below paragraph that after
> reinvite B-Party stopped RTP and started T38 packets in the same session
> but RtpProxy failed to send to the right recepient.

It's not T38 that needs special handling, but as I said, the reINVITE.
g-)
>>
>> > Adding to this, now after RTP relay starts successfully. B-Party (if
>> > Dialed number is a FAX) reinvites with T38 and the IP:Port info in SDP
>> > remains same. Now somehow RtpProxy is not recognizing the T38 packets
>> > becuase we are in the same session and RtpProxy start sending those
>> > T38 packets to SSW (signalling entity) instead of sending to MG. Please
>> > remember we are in the same session, and RtpProxy shud send these T38
>> > packets to MG, as it was sending RTP packets before ReInvite.
>> >
>> > is it a bug in RTPProxy, should I use MediaProxy instead ???
>>
>> You need to handle reINVITEs in a special way. Look at the Getting 
>> Started
>> scripts (and document) from onsip.org for how to do it both for rtpproxy 
>> and
>> mediaproxy.
>>
>> g-)
>>
>>
> 




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