Configuration manual

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Nortel Business Secure Router 222 Configuration — Advanced
Appendix M
SIP
The Session Initiation Protocol (SIP) is an application-layer control (signaling)
protocol that handles the setting up, altering, and tearing down of voice and
multimedia sessions over the Internet. SIP is used in VoIP (Voice over IP), the
sending of voice signals over the Internet Protocol.
SIP signaling is separate from the media for which it handles sessions. The media
that is exchanged during the session can use a different path from that of the
signaling. SIP handles telephone calls and can interface with traditional
circuit-switched telephone networks.
SIP Identities
A SIP account uses an identity (sometimes referred to as a SIP address). A
complete SIP identity is called a SIP URI (Uniform Resource Identifier). The URI
of a SIP account identifies the SIP account in a way similar to the way an e-mail
address identifies an e-mail account. The format of a SIP identity is
SIP-Number@SIP-Service-Domain.
SIP Number
The SIP number is the part of the SIP URI that comes before the @ symbol. A SIP
number can use letters like in an e-mail address ([e-mail], for
example) or numbers like a telephone number ([e-mail],
for example).