SIP

The Session Initiation Protocol (SIP) is a signaling protocol used for establishing sessions in an IP network. A session could be a simple two-way telephone call or a collaborative multimedia conference session.

SIP is a request-response protocol that closely resembles two other Internet protocols: HTTP and SMTP. Consequently, SIP works well with Internet applications. Using SIP, telephony becomes another Web application and integrates easily into other Internet services. SIP, which is a key component in the Windows CE Communications Service architecture, allows developers to build converged voice, test messaging, and presence services.

The primary benefits of SIP are its ability to create and manage any type of session and its ability to separate the physical devices, such as telephones, from the users and the service-logic from centralized control. This abstraction of service from physical devices is what allows features such as presence (actually subscriptions and notifications) and mobility to be possible. SIP provides the ability to locate and communicate with any entity represented by a Universal Resource Identifier (URI). This addressing schema allows SIP to use any combination of Internet technologies.

SIP is the protocol adopted by the telecommunication industry worldwide (wireline, cable, wireless, and public and private networks) for session management, call control, presence, and text messaging.

SIP is described in RFC 2543 and is approved by the Internet Engineering Task Force (IETF).

 Last updated on Saturday, April 10, 2004

© 1992-2003 Microsoft Corporation. All rights reserved.