Hello, I have some MC3810s that I want to use with SER over their PRI ports. The problem with these is that IOS 12.3 doesn't seem to support SIP registrar functions, so there is no way to get the DIDs to register with SER. Since these routers have static IP addresses, is it possible to have SER authenticate based on IP address? I know I could just add a ton of lines to my config file authorizing and routing them manually, but thoguht someone might know a better way to save their location like the registered users, and check the source IP vs the password field (something like put the IP address in the password field). I'm sure I'm far from the first that's ran into this, but couldn't find much so thought I'd ask for ideas. Thanks, Brian