Hi, I am having real difficulty to get this working. My provider force me a 2Wire device for Sip call. I manage to get away and have success with Linksys PAP2T and softphone like X-lite. I just cannot get Asterisk to work. I manage to register the trunk. I can make outgoing call but there is no voice on both ends. I check log status and it return with "rtp.c: RTP Transmission error of packet to 0.0.0.0:0: Invalid argument" I am using a public IP address. I end up puting "nat and externip" to get rid of the error. Having getting rid of the error, I still have no voice when connected. I tried alot of combination of command still dun work. username=6xxxxxx type=peer secret=xxxxxxx qualify=yes nat=yes localhost=127.0.0.1 insecure=very host=voip.xxxx.com fromdomain=voip.xxxx.com externip=6x.x.x.x dtmfmode=rfc2283 disallow=all context=default auth=md5 allow=ulaw&alaw relaxdtmf=yes Log files.... I appreciate if any guru here can advice me further to next stage. thank you.