Hi, Michael After some personal investigation, I've found param aggressive-nat-detection, and uncommented it in the profile internal: ./sip_profiles/internal.xml: <param name="aggressive-nat-detection" value="true"/> After this step, I can see fs_path for remote sipdroid phone: Call-ID: 845794751536@14.18.161.240 User: 1019@192.168.1.5 Contact: "user" <sip:1019@14.18.161.240:43305;transport=udp;fs_nat=yes;fs_path=sip%3A1019%40208.54.45.78%3A16146%3Btransport%3Dudp> Agent: Sipdroid/1.4.6 beta/T-Mobile G1 Status: Registered(UDP-NAT)(unknown) EXP(2010-05-24 17:13:49) Host: olegh.ath.cx IP: 208.54.45.78 Port: 16146 Auth-User: 1019 Auth-Realm: olegh.ath.cx MWI-Account: 1019@192.168.1.5 Call goes OK, phone works! Thank you for help, Oleg