Well, my Cisco 7940 IP phone arrived yeaterday, and I spent a while poking around on the web trying to upgrade it to SIP firmware to work with the asterisk exchange.
It arrived with me with version 3 SCCP firmware, and I had downloaded the Version 8 SIP firmware from the Cisco site – it’s available there for free, you just have to get it from an anonymous ftp server.
It appears though that you cannot do a single stage upgrade from version 3 to version 8, and that I was pretty stuck unless I could find an intermediate firmware – a version 6 sounded like the best bet. Now I don’t have a Cisco support contract for this – I believe from what I was reading that it’s not very expensive for one of these phones, but still, it goes against my better judgement. A little bit more poking around in various places, and I found voip-info.org a really useful source of information about voip of all sorts.
So I eventually managed to follow some of the instructions I found there, and got the phone upgraded to SIP version 6, then I had to get it integrated with the rest off the network.
I’ve already got a couple of PAP2’s hooked into an asterisk exchange, so I was already pretty familiar with that end of things, and it just needed me to add an entry for each line on the phone.
Then comes the fun bit, customising the graphics and services menu with xml served off a local web server, so now I’ve got tux on my 7940, and I’m writing some scripts for the web server to output XML for the phone.