I went to the Cisco 7960G Software Download Site and downloaded the P0S3-7-4-00.zip file which contained the 7.4 SIP Flash Image for 7940/7960 IP Phone’s.
Power on your phone and connect it to your network. You will need to change the IP address of your phone to a free one on your network or set it up to use DHCP, which is the way mine was configured by default.
There are apprently a couple of ways to unlock your phone depending on which verison of firmware that you have installed. For older phones you will need to press **# or on newer firmware select unlock config from the config menu and then type in the password (default is ‘cisco’).
My phone was using older firmware (3.1 MF.G2) so I hit the settings hard key on the phone, moved the “cursor” to option 3, but don’t select it just yet. Press **#, then press the select soft key on the 7960’s screen. You should see the padlock icon with an unlocked appearance. Press 32 and see if you have a YES option (alternate TFTP). If so press yes, then go to option 8 and edit the IP address.
From the CLI of your Asterisk box type: setup-cisco. This command will setup a basic SIPDefault.cnf in the /tftpboot directory of your Asterisk box.
Upload the P0S3-7-4-00.zip file to your servers TFTP root directory wihch in my case was /tftpboot on the A@H server. Don’t unzip it on your workstation and upload it. For some reason it doesn’t work.
From within your /tftbboot directory on your Asterisk box type uzip P0S3-7-4-00.zip.
From the command line type cp /tftpboot/cisco_util/* /tftpboot.
From the command line type chmod 777 /tftpboot/*.
Reboot your 7960 by disconnecting the power cable. Your phone should be able to aquire its IP from the DHCP server (if that is how you have it configured), connect to the TFTP server and start the upgrading your phone to the 7.4 release of the SIP firmware.
Once your phone has completed the upgrade, you will need to type rm /tftpboot/xmlDefault.CNF.XML and rm /tftpboot/XMLDefault.cnf.xml from the command line on your Asterisk box.