Hello, I have the following topology. Kamailio as SIP Proxy and Asterisk as B2BUA. In Kamailio I use rtpproxy for NAT users. The problem that I have is the following: -When the CSipSimple is registered the first call is always unsuccesfull. The following calls are always successful. If the application remains idle for a while the next call is unsuccessful again. From traces I saw that everything is OK in signaling part. -When I try with Zoiper and 3CX I have 1/20 successful calls. In any case from Asterisk side these calls can be seen as active but no media. Thanx, Theo _______________________________________________ SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users(a)lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users