Cisco CP3911 + FreePBX outside of LAN

Hi.

I have a very simple setup. FreePBX is installed on a VPS outside of my LAN. I have a CallCentric account linked to it. When you dial my callcentric phone number, it connects to an IVR, which announces a message, and then times out instantly and calls my phone (Cisco CP3911). If I don’t pick up it goes to my voicemail.

When I first set up my phone everything worked great. And then an hour or so later, all calls went to voicemail. I later discovered that the phone will accept incoming calls for about 1 hour, and then after then, it won’t accept incoming calls anymore. I can still make outgoing calls.

I’m sure this is something simple that I’m missing. (keepalives maybe?). I’m kind of a SIP n00b. I run a small computer repair business (very small, it’s just me) and wanted an IP phone instead of regular phone, so that I can have an IVR for a cool intro, and for when I grow and have more staff.

Thank you very much,
Zack Magee

Anybody have any input on this?

If I may ask, how did you get the CP3911 set up in the first place? I can’t even get mine to work at all, despite what I believe to be a properly crafted SEP(MAC Address).cnf file. It doesn’t even appear as though the phone is attempting to register with the FreePBX server (asterisk running in debug level 9 shows nothing).