That's interesting, I use TWC not Comcast and am still having the issue. I tried sip, sip7 and sip-central01 and have the problem on all of them, looks like I am intermittently losing registration since in Control Panel it sometimes shows "no devices connected" which is causing incoming calls to go to failover when this happens . I even tried setting the registration interval to 30 seconds and I noticed that sometimes I still lose registration before the 30 seconds is up. I know it sounds like a router issue, but I have keepalive on the ATA set to 15 secs and my udp timeouts on my router are 10 secs for unreplied and 300 for assured which has been working fine until recently. These settings also work fine with other providers, it's only with Voipo that I'm seeing the issue.

What is the dns name for the Chicago server so I can give that a try?