This office has a bunch of Polycom SoundPoint IP 320 phones, and a single Grandstream HT801 (connected to a FAX machine for outgoing FAXes). I can make a call from the phones to outside numbers. I can make a call from the HT801 to local phones. But I can't call from the HT801 to outside numbers. The last important thing that happens in the failed call is this: 2021-04-13 17:28:15.260844 [DEBUG] sofia.c:7406 Channel sofia/external/<number> entering state [calling][0] The difference between the work and not work seems to be this: When I call from a phone to an outside number, it does this: Local SDP: v=0 o=FreeSWITCH 1618335260 1618335261 IN IP4 <external-IP> s=FreeSWITCH c=IN IP4 <external-IP> t=0 0 m=audio 25104 RTP/AVP 0 8 101 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 a=sendrecv When it tries to call from the HT801 to an outside number, it does this: Local SDP: v=0 o=FreeSWITCH 1618327543 1618327544 IN IP4 <external-IP> s=FreeSWITCH c=IN IP4 <external-IP> t=0 0 m=audio 32552 RTP/AVP 0 8 102 9 101 103 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:102 opus/48000/2 a=fmtp:102 useinbandfec=1; maxaveragebitrate=30000; maxplaybackrate=48000; ptime=20; minptime=10; maxptime=40; stereo=1 a=rtpmap:9 G722/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=rtpmap:103 telephone-event/48000 a=fmtp:103 0-16 a=ptime:20 a=sendrecv Is that why it doesn't answer? If so, how do I change it? I should mention that when I tried this at home, it worked, but when I attempted to install it here at the bookstore, it didn't. The Comcast router at my home is a little different; they use a Netgear router here; and I may have upgraded Freeswitch between the time it worked and now. -- Steve