Some other good sources of information: The 7941G has two line buttons, the 7961G has six.
Line buttons are configurable as outgoing SIP channels ("SIP lines") or as configurable speed dial buttons.
The value As many as 11 characters to show in the upper right of the phone's display, if not set it defaults to the value of the name setting for the lowest number line button (i.e.
The phone does not come with a power adapter, so unless you have a POE capable switch you will need either an external power brick that plugs into the phone's power jack (e.g.
A SMARTnet contract is the easiest way to gain legal access to all versions of Cisco firmware.
A much more complete discussion of SMARTnet contracts is on Cisco page.
POE offers a single cable solution, but may potentially result in lower audio quality (most corporate installations of these phones use POE).
The 79x1 phones are also compatible with the proprietary/pre-standard POE implementation used by the 79x0 phones.