Tips on using the Cisco 7960 phone with the pbxnsip PBX

Cisco’s 7960/7961 and 7940/7941 are probably the most popular VoIP phones today. The PBX supports the SIP version of this phone and most of the features are accessible through this endpoint.
We used a Cisco 7960, Firmware Version POS3-07-5-00 (Boot Load ID PC030300, DSP Load ID PS03AT46) for the tests. Previous versions have problems with the authentication; therefore it is a good idea to move the phone to this version.
Recently Cisco released the 8.x series of the firmware, and it seems that Cisco is taking SIP quite serious now. If you can, use the latest 8.2 version, which seems to be really good.

Plug and Play

The PBX supports plug and play for the Cisco. There are two ways to make plug and play happen:

• Specify the tftp server address in DHCP. This is the typical way that Cisco phones expect these settings. If you are using DHCP servers in Linux, IOS or Windows, this should be no problem and is definitively the best option for you.
• Manually specify the tftp address in the interface of the phone. This is usually the last resort when you are using DSL routers with built-in DHCP servers, which typically do not provide a setting for the tftp server.

Be careful, when you use the tftp protocol, all configuration data including passwords are sent in clear-text via the network. Never versions of the Cisco firmware support encryption of the configuration information, but unfortunately the encryption algorithm is now public open and you need to use a tool provided by the vendors to encrypt the configuration files. If you want to go this way, just put the encrypted files into the tftp directory of the PBX, and the PBX will then just work as a tftp server.

Messages-Waiting

If the device is used with the plug-and-play, then the MWI is set up automatically. If the device is set up manually, you must set the “messages URI” was set to the account URI, so that pressing the messages button will go to the mailbox account. If you don’t do this, the phone will not display the MWI events.

Other usage comments

Interestingly, the Cisco does not offer an option to reject a call. The phone support the Alert-Info header (which changes the ring melody), but it does not support the Call-Info header which is necessary to get the paging feature working.