I'm wondering about these values:
sip registration retry timer: 10 sip registration renewal timer: 15 sip registration timeout retry timer: 10 sip registration period: 60 sip rport: 1
They seem a bit short, especially on a LAN. Do you really need your phones to re-register every 45 seconds? Try setting sip registration period to 600 That's 10 minutes. sip registration renewal timer can be a bit longer - 30 seconds maybe, or 60 if you are at all worried about reliability. The sip registration renewal timer sets how long BEFORE expiry that the phone will re-register. I wonder if that value is too short, and something is rejecting it as invalid. Here's a section from my default config. It seems to work fairly well. If that doesn't work, we probably need to check the sofia profile. Let me know how you make out. -Tim sip dtmf method: 0 sip rtp port: 10000 sip mode: 0 sip silence suppression: 0 sip digit time out: 3 sip update callerid: 0 sip send mac: 1 sip rport: 0 sip blf subscription period: 1800 sip registration period: 3600 sip registration renewal timer: 1200 sip T2 timer: 2000 sip transaction timer: 12000 sip use basic codecs: 0 sip customized codec: payload=115;ptime=20;silsupp=off,payload=97;ptime=20;silsupp=off,payload=9;ptime=20;silsupp=off,payload=0;ptime=20;silsupp=of$