Quote Originally Posted by GreenLantern View Post
Aha, that makes a lot more sense now. I didn't fully understand what you were running into before. Great workaround, but wow, a lot of work.

So all of this was unique to the 7970? I haven't noticed any trouble with MWI for multiple accounts with other phones. But I rarely use Cisco. Cisco (and Polycom) seem overly complicated to me.
Yes, just the 7970. My 7960s and 7961s have worked fine for well over a year. Cisco made some intentional changes to the SIP firmware on the 7970 that broke all sorts of NAT related stuff. While the change was technically within the RFC spec, it broke most direct connections traversing NAT. They claim it was a change made for security, but I just don't see it how it makes anything more secure. But it does make things more difficult for you to use a 7970 outside of a Cisco Call Manager environment... go figure.

Now that I know how, setting up another one is simple. It didn't help that Voipos NOTIFY packets are missing a required SIP header, and it didnt help that Voipo doesnt support MWI subscription, and it didn't help that Cisco intentionally screwed up NAT functionality. I spent a lot of time thinking the phone specific config file was wrong (it didn't help that Cisco reports nothing for an invalid config), but as it turns out, once you get Asterisk running with NAT, and the trunk mapping correct (on different UDP ports for different lines), pretty much any of the available configs for the 7970 out on the internet work fine.