Session Initiation Protocol (SIP) and Its Functions
VoIP, WebRTC, and many such names have been making a lot of buzz in the digital communication world in the last few years. On the face of it, these appear to be more complicated than they are and SIP is no exception. However, all the buzz around SIP is because of the fact that it is a widely adopted standard. It enables service providers and enterprises to eliminate cost and complexity, accelerate the pace of innovation and avoid vendor lock-in.
SIP is not a complicated technology as most people perceive — instead, it’s a lightweight set of protocols that are delivered via a SIP provider that empowers enterprises to unlock the vast benefits of internet-based phones.
In simple language, “protocol refers to a set of universal standards for computer communication.” SIP refers to a “signaling protocol” used for initiating, maintaining, modifying, and terminating real-time communications sessions between internet protocol (IP)devices.
Table of Contents
A Breakdown of The Term SIP
Session Initiation Protocol — ‘Initiation translates to or means beginning. SIP means initiating a live communication session such as phone calls, conferencing, and videos. SIP technology is widely used for VoIP calls, but it has many other uses as well such as video conferencing, instant messaging, and even computer games. Basically, SIP is used to set up and terminate sessions, or conversations, in a UC (Unified Communications) environment.
Voice over Internet Protocol (VoIP) telephony is built on the basic tenets of SIP. Making a shift to VoIP and SIP trunking gives enterprises more communication options than traditional legacy PRI (primary rate interface) services.
SIP trunking uses IP to enable organizations to make calls through PSTN (Public Switched Telephone Network). For this, SIP requires an internet connection, a VoIP vendor, or an IP-enabled PBX.
Over the years, SIP has become the backbone of the VoIP, voice, and video world. It is the matriarchal figure who holds the infrastructure together, enabling these applications from different vendors to communicate and integrate with one another. These applications range from presence, instant messaging, voice, or video. SIP boosts productivity for businesses by helping them take advantage of these UC applications.
A Brief History About SIP
SIP was developed in 1996, by the “Internet Engineering Task Force” and standardized in 1999. It was originally designed by Mark Handley, Henning Schulzrinne, Eve Schooler, and Jonathan Rosenberg in 1996 to facilitate establishing multicast multimedia sessions.
SIP was accepted as a 3GPP signaling protocol and permanent element of the IP Multimedia Subsystem (IMS) architecture for IP-based streaming multimedia services in cellular networks in November 2000. In June 2002 the specification was revised and various extensions and clarifications have been published since.
SIP addressed the evolving needs of IP communications, such as in-house support for mobility, interoperability, and multimedia support. SIP was originally designed to provide a signaling and call setup protocol for IP-based communications supporting the call processing functions and features present in the public switched telephone network (PSTN) with a vision of supporting new multimedia applications. With the evolving needs, it has now been extended for video conferencing, streaming media distribution, instant messaging, presence information, file transfer, Internet fax , and online games too.
What makes SIP stand apart from its contemporaries is that SIP has roots in the Internet community rather than in the telecommunications industry.
