[Serusers] rtpproxy question

[Klaus Darilion]

Hi!

As the RTP relaying does not work with 2 RTP proxies, how can a proxy detect
if the RTP stream is already redirected to an RTP proxy?

My problem is the following scenario:

UA1   --NAT--   SIP proxy 1   --   SIP proxy 2   --NAT--   UA2
                 rtpproxy1          rtpproxy2

UA1 invites UA2. SIP proxy 1 detects that UA1 is behind NAT and enables the
rtpproxy1 and forwards the invite to SIP proxy2. SIP proxy 2 knows that UA2
is also behind NAT. Usually, SIP proxy 2 would activate the rtpproxy2, but
in this case this would not work as there is already an rtpproxy involved.
How can the SIP proxy 2 detect that the IP address in the SDP is the IP
address of an RTP proxy?

regards,
Klaus