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Intro to SIP

Hi there -

As I mentioned earlier, here I would like to take chance in introducing SIP - a signaling protocol widely used in the current Telecommunications world. SIP is a well known signaling protocol for controlling multimedia sessions such as voice/video calls over Internet Protocol (IP) networks.

SIP

- SIP stands for Session Initiation Protocol
- It is a very lite signaling communications protocol used for establishing sessions in an IP network. A session could be referred as a simple two-way voice call (or) a collaborative conference multimedia call.
- Simply, SIP is a mechanism to establish, modify and tear down the multimedia sessions. 
- SIP is a protocol which resembles HTTP (Hyper Text Transfer Protocol)
- The reason it became very famous because of its simplicity to program, troubleshoot and integrate. Moreover, it is a open source and referred to RFC 3261.

Brief history of SIP

- SIP was originally designed by Henning Schulzrinne and Mark Handley in 1996
- SIP has been developed and standardized with RFC 3261 under IETF 

SIP in TCP/IP suite

Below image clearly shows that SIP is a Application Layer protocol which uses  TCP/UDP (Transport Layer protocols).


H.323 vs SIP

To someone who have idea about H.323 - a protocol which was widely used in enterprise real-time communications world and standardized by ITU, you can compare these two protocols and get an overall understanding why and how SIP is ruling the current Telecom world.

Below is the link which has the best comparison of H.323 and SIP. Up to my knowledge this is the best comparison which I had found on internet.



Summary

SIP is a
  • Text based protocol like HTML, SMTP etc
  • Client/Server model also called as Request/Response model
  • Signaling communications protocol
  • Application Layer protocol 
  • Uses TCP/UDP/TLS from Transport Layer

Please put up your comments which helps me in knowing your expectations. I will try definitely making this site a valuable resource for all of YOU!







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