Session Initiation Protocol (SIP) is a call control protocol that establishes and terminates "media sessions." Examples of media sessions include phone calls, e-mail, streamed video, and instant messaging. SIP standardizes these communications by adding a protocol that is independent of the underlying network and infrastructure. It is not dependent on ports, pipes, hardware or software, but allows all of these components to talk with each other and media to be controlled independently from the network.
SIP is the packet voice protocol of choice by major IP voice initiatives such as the G3 wireless consortium and Microsoft. A highly flexible protocol, SIP specifies the basic and supplementary services to create, modify, and delete these multimedia sessions or calls. By utilizing SIP, we enable customers to use applications regardless of the client's network or access type.
SIP's foundation in HTTP allows it to integrate with Web, e-mail, and other data applications using a URL format, providing a highly flexible protocol. SIP's ease of use and flexibility pave the way for new services and capabilities in the future.
