SecurityEvent="ChallengeSent",EventTV="1367741794-435078",Severity="Informat ional",Service="SIP",EventVersion="1",AccountID="sip:venu at 192.168.0.35",Sess ionID="0x337bf68",LocalAddress="IPV4/UDP/10.10.1.3/5060",RemoteAddress="IPV4 /UDP/192.168.1.90/5060",Challenge="41cdcd16" ^^^ The other networks confuse me, and perhaps asterisk. Perhaps serverA:sip.conf udpbindaddr=192.168.0.35 ; IP address to bind UDP listen socket to (0.0.0.0 binds to all) ; Optionally add a port number, 192.168.1.1:5062 (default is port 5060) serverB:sip.conf udpbindaddr=192.168.0.36 ; IP address to bind UDP listen socket to (0.0.0.0 binds to all) ; Optionally add a port number, 192.168.1.1:5062 (default is port 5060) Alec