A SIP-URI is the addressing format used to identify users in a SIP-based phone system. In simple terms, a SIP-URI is like a phone number for SIP calls. The SIP URI resembles an e-mail address and is written in the following format:

SIP-URI = sip:x@y:Port  where x=Username and y=host (domain or IP)

Note: If you do not specify a port, the default sip port will be assumed (5060). This is shown in the first two examples below. If you have changed the default SIP port to something else then you need to specify it in the SIP-URI (third example below).

Examples:

1. sip:[email protected]
2. sip:[email protected]
3. sip:[email protected]:6000

The SIP URI scheme has been defined in the RFC 3261 standard.

Each SIP-URI must follow the correct syntax to ensure SIP messages reach the right endpoint.