Here is the layout: SoftPhone on WinXP @ 10.0.0.201 Asterisk on VirtualBox on this WinXP (Bridged) @ 10.0.0.211 HTC SmartPhone @ 192.118.11.112 (STUN is active) When trying to connect via GPRS, I Can see the following symptoms: 1. RTP from the SmartPhone (192.118.11.112) is not reaching the asterisk, 2. RTP from Desktop SoftPhone to 192.118.11.112 dose not heard in the SmartPhone I would add that when connecting with WiFi (same LAN) everything works fine [thanks for the STUN tip *Angelos;-) ]. *Moreover, the signaling part works smoothly. Using WireShark as well as looking at the softphone behavior and logs, I see all the REGISTER, INVITE, ACK, and others traversing over the NATs without any problem. dose anybody coped with such or alike? -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20080214/c9d0f190/attachment.html