A Session Initiation Protocol (SIP) phone is a telephone that uses the SIP protocol to establish and control multimedia sessions, such as voice, video, and instant messaging. SIP phones can be either hardware-based or software-based. Hardware-based SIP phones are standalone devices that connect to a network and have a physical user interface. Software-based SIP phones are computer programs that run on a personal computer or mobile device.
SIP phones offer a number of benefits over traditional analog phones, including: