What type of address does SIP utilize for user identification?

SIP (Session Initiation Protocol) utilizes SIP URIs (Uniform Resource Identifiers) for user identification. A SIP URI allows for the specification of both the user and the domain, using a format similar to an email address. For example, a SIP URI would look like sip:user@example.com. This structure helps identify endpoints in a SIP network, enabling session management for voice, video, and messaging services.

Unlike an IP address, which specifies the location of a device within a network, or a MAC address, which identifies a physical network interface, the SIP URI provides a more abstract means of addressing users in SIP communications. Email addresses are also distinct from SIP URIs, as they do not inherently define the communication protocol used; they are typically used for mail transfer rather than signaling for SIP sessions.

The use of SIP URIs ensures that users can be identified and reached regardless of the underlying network address, which enhances flexibility and portability in VoIP communications. Thus, SIP URIs are essential for the routing and signaling mechanisms that SIP implements for establishing and managing communication sessions.