Nortel 2001 Installation And Operation Manual page 246

Page 246 of 302
553-3001-368 Standard 4.00
SIP Phone
SIP Phones communicate with SIP-network components which reside on the
Signaling Server. These components include the following:
• SIP Gateway — The SIP Gateway provides a direct trunking interface
between the CS 1000 systems and a SIP domain. The SIP Gateway is
implemented according to SIP standards. The SIP Gateway connects
CS 1000 systems to other Nortel Networks or third-party SIP-enabled
products. This direct SIP interface is used to interwork with products
such as the Multimedia Communication Server (MCS) 5100 or CS 2000.
• SIP Redirect Server — The SIP Redirect Server is used to facilitate
centralized dialing plan management and the configuration of the
network routing information for the SIP domain. A SIP Redirect Server
translates telephone numbers recognized by Enterprise Business
Network (EBN) voice systems to IP addresses in the SIP domain. As a
result, the SIP Redirect Server interfaces with SIP-based products. The
SIP Redirect Server has the ability to access the CS 1000 system's
endpoint/location database in order to direct SIP Gateways and SIP
Phones within the networked environment.
• SIP Registrar — The SIP Registration Server, which is also known as the
SIP Registrar, is used for endpoint registration. Registration is one way
that the server can learn the location of a user (SIP client). Upon
initialization, and at periodic intervals, a user's telephone sends
REGISTER messages to the SIP Registrar in the same domain. The
contact information from the REGISTER request is then made available
to other SIP servers, such as proxies and redirect servers, within the same
administrative domain. The registration process precedes the call setup.
CS 1000 Release 4.0 also supports SIP-based Converged Desktop Service
(CDS). CDS provides the telephony features of the CS 1000 systems, along
with the multimedia applications of the MCS 5100. CDS allows a user to
have an identity in the SIP domain (for example, a registered PC client), as
well as in the CS 1000 system as a telephone. For further information, refer
to Multimedia Communication Portfolio Interworking - Basics
(NN10372-111), and for information about calls between SIP Phones and SIP
Gateways, refer to IP Peer Networking: Installation and Configuration
(553-3001-213).
February 2005