[OpenSIPStack] Questions Regarding RTP communication in openSBC

[Ashish K. <ash...@gm...>]

Hi Joegen,

I have two questions for RTP communication in openSBC.

1) clients have to use the same RTP ports to send the RTP packets on which
they recieve RTP packets. So if the client is recieveing RTP packets on port
8000, Cient will use 8000 only to send the RTP packets?

2) When natted client initiated the call,  for example Client A which is
behind a NAT, calls B through openSBC, the first RTP packets need to be
recieved from Client A, at openSBC, in order to send the RTP packets from
Client B to Client A. this is because of NAT device, the RTP packets from A
comes from different port than what was said in the SDP offfer and therefore
RTP packets from B need to be send to this new port.  is my understanding
correct. Please clarify.?

Please reply.

Thanks.

-Ashish