SIP protocol

In this lecture, Federico and Monika talks about SIP architecture, his components, his addressing and localization, the security, real implementations and competitors.

SIP is a signaling protocol to establish “session” in internet. Allow the exchange of “session description information” between the caller and the called. It is an elastic protocol that allows new features through extensions. The basics functions of a signaling protocol are:

- manage the user’s registration and their localization

- have a mechanism to establish and destroy connections end-to-end by some request message

- Route response message from destination to the source in order to ask to the caller

 SIP uses easy client-server architecture with 2 different messages: request or known as well as method and response. About security, SIP provides also security in each layer of the ISO/OSI stack, it supports Ipsecurity and TLS. Real SIP implementations are the VoIP phones. VoIP is getting more and more popular, and at the same time SIP is getting more and more complicated. It is possible that it will be replaced by some different protocols, but now its position on the market is stable.