(A) Session Maintenance Protocol: coordinates the initiation and termination of communication sessions:
(B) Real – time Streaming: Protocol designed for use in entertainment and communications systems to control streaming media servers.
The Real Time Streaming Protocol (RTSP) is a protocol designed for use in entertainment and communications systems to control streaming media servers. The protocol is used for establishing and controlling media sessions between end points. Clients of media servers issue VHS-style commands, such as play, record and pause, to facilitate real-time control of the media streaming from the server to a client (Video On Demand) or from a client to the server (Voice Recording).
(C) Real-time Transport Protocol (RTP) is a application layer and network protocol for delivering audio and video over IP networks. RTP is used in communication and entertainment systems that involve streaming media, such as telephony, video teleconference applications including WebRTC, television services and web-based push-to-talk features.
Real-Time Transport Protocol
Real-time transport protocol (RTP) is an application layer protocol that provides end-to-end delivery services of real-time audio and video. RTP provides payload identification, sequencing, time-stamping, and delivery monitoring. UDP provides multiplexing and checksum services. RTP can also be used with other transport protocols like TCP , and in conjunction with other signaling protocols like SIP or H.248.
(D)Real – time Transport Control Protocol: works with Real-Time Protocol (RTP) to monitor data delivery on large multicast networks.
Real-Time Transport Control Protocol
The real-time transport control protocol (RTCP) augments the RTP protocol to monitor the quality of service (QoS) and data delivery monitoring as well as provide minimal control and identification capability over unicast or multicast services independent of the underlying network or transport protocols. The primary function of the RTCP protocol is to provide feedback on the quality of data distribution that can be used for flow and congestion control.
(D) Session Initiation Protocol: an application-layer signaling protocol establishes, manages and terminates multimedia sessions.It is an application-layer control protocol that can establish, modify, and terminate multimedia sessions such as Internet telephony calls.. Session initiation protocol (SIP) is an application-layer signaling protocol for creating, modifying, and terminating sessions with one or more participants. SIP sessions include Internet multimedia conferences, Internet telephone calls, and multimedia distribution. SIP invitations create sessions carrying session descriptions,
The core SIP protocol, specified in Internet Engineering Task Force (IETF) Request for Comments (RFC) 2543, is built on foundation IP protocols, such as HTTP and Simple Mail Transfer Protocol (SMTP). As such, it supports a request/response transaction model that is text-based, similar to e-mail, and self-describing.
SIP architectural components:
- An SIP client is an end system with the SIP User Agent (UA) residing in it. The user agent consists of two components: the User Agent Client (UAC) is responsible for sending SIP requests, and the User Agent Server (UAS) listens for incoming requests, and prompts a user or executes a program to determine responses.
- A Proxy Server is responsible for routing and delivering messages to the called party. It receives requests and forwards them to another server (called a next-hop server), which may be another proxy server,
- A Redirect Server also receives requests and determines next-hop server(s). Instead of forwarding the request there, however, it returns the address(es) of the next-hop server(s) to the sender.
- A Locator Service is used by an SIP server to obtain information about a callee's possible locations.
- A Registration Server receives updates on the current locations of users. It is typically colocated with a proxy redirect server. The server may make its information available through the location server.