Configuring Cisco 7975 IP Phones for SIP
Anyone who has had the "pleasure" of trying to configure a Cisco 7975 phone with a SIP IP PBX system such as Asterisk, trixbox, or 3CX can attest to the fact that the phones are very picky with their config files and much of the information that is really handy to know is simply not documented anywhere. On top of that, to get the phones to even work right you have to use very specific versions of the SIP...