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Explore multimedia session protocols like RTSP, SIP, and more for seamless audio and video streaming with QoS management and session control in distributed conferences.
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CS 414 – Multimedia Systems DesignLecture 23 – Multimedia Session Protocols Klara Nahrstedt Spring 2014 CS 414 - Spring 2014
Administrative CS 414 - Spring 2014
Outline • Multimedia Protocols – Standards • RTP/UDP/IP – Transmission Protocol • RTCP Control/Negotiation Protocol to RTP • RTSP – Control VOD Negotiation Protocol • SIP – Session Initiation Protocol CS 414 - Spring 2014
Internet Multimedia Protocol Stack Media encaps (H.264, MPEG-4) DASH APPLICATION RTSP RSVP RTCP Layer 5 (Session) SIP RTP HTTP Layer 4 (Transport) TCP DCCP UDP KERNEL Layer 3 (Network) IP Version 4, IP Version 6 AAL3/4 AAL5 MPLS Layer 2 (Link/MAC) Ethernet/WiFi ATM/Fiber Optics CS 414 - Spring 2014
Session control in layer 5 CS 414 - Spring 2014
Session Management (Layer 5) SESSION MANAGER Conference control Participant Management Session Control Protocol (e.g., RTSP) Session Control Media control Configuration control Presentation data communication whiteboard Continuous data communication video Continuous data communication audio Control of multiple multimedia connections Separates control aspects from transport aspects CS 414 - Spring 2014
Session Manager • Tasks: • Membership control • Monitoring of shared workspace • Coordination of Media control management • Exchange of QoS parameters • Conference control management – establishment, modification, termination CS 414 - Spring 2014
Session Control • Session Described by • Session state • Name of session, start, valid policies • Session management – two steps for state processing • Establishment of session • Modification of session CS 414 - Spring 2014
Session Control • Conference Control • Centralized or distributed approach • Media Control • Synchronization • Configuration Control • Negotiation of QoS parameters, admission control and reservation/allocation of resources • Membership Control • Invitation of users; registration of users, change of membership CS 414 - Spring 2014
Examples of Session Control protocols: RTSP, SIP, SAP, … CS 414 - Spring 2014
Real-Time Streaming Protocol (RTSP) Audio Video Decoder AudiovideoCoder Session Control RTSP RTSP RTP RTP CLIENT SERVER Application Protocol for Control of multimedia streams This is not an application data transmission protocol, just remote control protocol between client and server CS 414 - Spring 2014
RTSP • Approved as Internet Draft, February 2, 1998, authors H. Schulzrinne, A. Rao, R. Lanphier • Enables controlled, on-demand delivery of real-time data such as audio and video • Intends to control multiple data delivery sessions • Provides means for choosing delivery channels • UDP • Multicast UDP, • TCP CS 414 - Spring 2014
RTSP Methods CS 414 - Spring 2014
RTSP – Aggregate and Stream Control DESCRIBE (aggregate stream) SETUP RTSP RTSP SID Decoder Coder PLAY RTP RTP ESTABLISH PLAY CLIENT SERVER CS 414 - Spring 2014
Streaming media: meta files client CS 414 - Spring 2014 RTSP Presentation by H. Schulzrinne, 2001
Streaming Media: RTSP CS 414 - Spring 2014 RTSP Presentation by H. Schulzrinne, 2001
RTSP Operation CS 414 - Spring 2014 RTSP Presentation by H. Schulzrinne, 2001
Conclusion • Internet protocol suite has now basic ingredients to support streaming audio and video • Both for distribution and communication applications • Challenges: • No session control protocol that can be used to perform floor control in distributed multimedia conferences • Network reliability and deployment multicast of services with predictable quality-of-service are major hurdles beyond need for continuous upgrades in network capacity CS 414 - Spring 2014