The IP address is 4 numbers separated by dots (i.e. 192.168.1.5)
Different models have different ways to know the IP address of the phone:
If you have a Sound Point phone press the menu button and then press 2 2 1.
You can also press the menu button and then go to settings -> status -> Network -> TCP/IP parameters
On your phone just touch the LCD screen and you will see it. You may need to press the home button.
On your phone press the setup button (it looks like a piece of paper with the corner folded over) and then select network.