[Serusers] Rtpproxy: media not forward

Dear all, I have installed rtpproxy from http://www.openser.org/downloads/snapshots/rtpproxy/rtpproxy-cvs-latest.tgz on the same computer as Openser. I started it without options. /var/run/rtpproxy.pid and .sock are created. I suppose a communication is established between OpenSer and Rtpproxy as SDP messages are correctly replaced, it means "Connection Information c" shows rtpproxy IP address and ports. Also both UAs sent RTP media to rtpproxyIP:port described in SDP body, but rtpproxy doesn't forward any RTP packets from one UA to the other. Tcpdump -n udp and host 213.48.xxx.yyy result: 11:48:49.191130 IP 213.48.xxx.yyy.2236 > 207.245.aaa.bbb.35000: UDP, length 60 11:48:49.250183 IP 213.48.xxx.yyy.2236 > 207.245.aaa.bbb.35000: UDP, length 60 11:48:49.255407 IP 213.48.xxx.yyy.2237 > 207.245.aaa.bbb.35004: UDP, length 60 11:48:49.297050 IP 213.48.xxx.yyy.2236 > 207.245.aaa.bbb.35000: UDP, length 60 11:48:49.297275 IP 213.48.xxx.yyy.2237 > 207.245.aaa.bbb.35004: UDP, length 60 11:48:49.335890 IP 213.48.xxx.yyy.2237 > 207.245.aaa.bbb.35004: UDP, length 60 11:48:49.339723 IP 213.48.xxx.yyy.2236 > 207.245.aaa.bbb.35000: UDP, length 60 11:48:49.393997 IP 213.48.xxx.yyy.2237 > 207.245.aaa.bbb.35004: UDP, length 60 Have you ever come across that issue? How can I get 207.245.aaa.bbb.35000 > 213.48.xxx.yyy.2237? Does this problem occur because both UAs are in the same local network? (I don't thing so) I would be very thankful if you could give me an idea about it. Thanks a lot Paul