Network Devices

SIP (Session Initiation Protocol)

SIP is an application layer protocol designed to be independent of the underlying transport layer; it can run on transmission control protocol (TCP), UDP, or SCTP. It is a text based protocol, incorporating many elements of the HTTP and the SMTP.

The session Initiation Protocol is a signaling communication protocol, widely used for controlling multimedia communication sessions such as voice and video calls over IP.
The protocol defines the messages that are sent between peers which govern establishment, terminations and other essential element of call. SIP can be used for creating, modifying, and terminating two party (unicast) or multiparty (multicast) sessions consisting one or several media streams. Other SIP applications include video conferencing, streaming multimedia distribution, instant messaging, presence information, file transfer and online games.
SIP work in conjunction with several other application layer protocols that identify and carry the session media identification and negotiation is achieved with session description protocol (SDP). For the transmission of media stream a(voice, video) SIP typically employs the Real-Time transport protocol (RTP), which many be secured with the secure Real-Time transport protocol (RTP). For secure transmissions of SIP message the protocol may be encrypted with transport layer security TLS.