CS 414 – Multimedia Systems Design Lecture 20 – Multimedia Session Protocols Midterm ResultsSlide Number 3MP1 Results / HW1 ResultsAdministrative Outline Internet Multimedia Protocol StackReal-Time Streaming Protocol (RTSP)RTSP RTSP MethodsRTSP – Aggregate and Stream Control Streaming media: meta filesStreaming Media: RTSPRTSP OperationSession Description Protocol (SDP)SDPSDP InformationSignaling for IP TelephonyIP Telephony Signaling Protocol (Requirements)IP Telephony Signaling (Requirements) SIP (Session Initiation Protocol)Call Setup Process using SIPSIP Redirect Server OperationSIP - Message SIP – Addressing and NamingSIP Requests/MethodsSIP ResponsesSAP – Session Announcement Protocol ConclusionCS 414 - Spring 2011CS 414 – Multimedia Systems DesignLecture 20 –Multimedia Session Protocols Klara NahrstedtSpring 2011Midterm Results Average = 66.7 Median = 66.0 Standard deviation = 13.52 Max = 91.5 Min = 34 Count = 35Midterm Grade Allocation Below 36: F 36 – 48: D Range 48 – 60: C Range 60 – 72: B Range 72 – 84: A Range 84 and above A+CS 414 - Spring 2011CS 414 - Spring 2011MP1 Results / HW1 ResultsMP1 Scores Count: 36 Maximum: 114 Minimum: 64 (will post statistics after class, since the stats have to be calculated on the 1-100 score – mandatory part only)HW1 Scores Count: 36 Average: 83.1 Median: 84.5 Maximum: 98 Minimum: 56 Standard Deviation: 10:93CS 414 - Spring 2011Administrative MP2 Posted: March 7, 2011 Deadline: March 30, 2011, 11:59pm (Compass time). Submission: via compass (see homework specification) Help Session: March 11, 7-8pm, SC1111 No class on March 11 due to EOHCS 414 - Spring 2011Outline Multimedia Protocols – Standards RTSP SIP SDP SAPCS 414 - Spring 2011Internet Multimedia Protocol StackCS 414 - Spring 2011AAL3/4IP Version 4, IP Version 6UDPMedia encaps(H.264, MPEG-4)RTPATM/Fiber OpticsEthernet/WiFiTCPSIPRTSP RSVP RTCPAAL5KERNELAPPLICATIONLayer 4(Transport)Layer 3(Network)Layer 2(Link/MAC)Layer 5(Session)MPLSReal-Time Streaming Protocol (RTSP) Application Protocol for Control of multimedia streams This is not an application data transmission protocol, just remote control protocol between client and serverCS 414 - Spring 2011SERVERCLIENTRTPRTPRTSP RTSPSession ControlAudiovideoCoderAudioVideoDecoderRTSP 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 2011RTSP MethodsRequest Direction DescriptionOPTIONS S <-> C Determine capabilities of server (S) or client (C)DESCRIBE C -> S Get description of media streamANNOUNCE S <-> C Announce new session descriptionSETUP C -> S Create media sessionRECORD C -> S Start media recordingPLAY C -> S Start media deliveryPAUSE C -> S Pause media deliveryREDIRECT S -> C Use other serverTEARDOWN C -> S Destroy media sessionSET_PARAMETER S <-> C Set server or client parameterGET_PARAMETER S <-> C Read server or client parameterCS 414 - Spring 2011RTSP – Aggregate and Stream Control CS 414 - Spring 2011SERVERCLIENTRTPRTPCoderDecoderDESCRIBE(aggregate stream)SETUPSIDRTSPRTSPPLAYESTABLISHPLAYStreaming media: meta filesCS 414 - Spring 2011RTSP Presentation by H. Schulzrinne, 2001clientStreaming Media: RTSPCS 414 - Spring 2011RTSP Presentation by H. Schulzrinne, 2001RTSP OperationCS 414 - Spring 2011RTSP Presentation by H. Schulzrinne, 2001Session Description Protocol (SDP) SDP is Text Format for describing multimedia sessions Not really a protocol (similar to markup language like HTML) Can be carried in any protocol, e.g., RTSP or SIP Describes unicast and multicast sessionsCS 414 - Spring 2011SDP There are five terms related to multimedia session description: Conference: It is a set of two or more communicating users along with the software they are using. Session : Session is the multimedia sender and receiver and the flowing stream of data. Session Announcement: A session announcement is a mechanism by which a session description is conveyed to users in a proactive fashion, i.e., the session description was not explicitly requested by the user. Session Advertisement : same as session announcement Session Description : A well defined format for conveying sufficient information to discover and participate in a multimedia session.CS 414 - Spring 2011SDP Information Session description v= (protocol version) ; o= (originator and session identifier) s= (session name) ; i=* (session information) u=* (URI of description) ; e=* (email address) p =* (phone number) ; c=* (connection information -- not required if included in all media) ; b=* (zero or more bandwidth information lines) One or more time descriptions ("t=" and "r=" lines; see below) z=* (time zone adjustments) k=* (encryption key) a=* (zero or more session attribute lines) Time description t= (time the session is active) ; r=* (zero or more repeat times) Media description, if present m= (media name and transport address) ; i=* (media title) c=* (connection information -- optional if included at session level) b=* (zero or more bandwidth information lines) k=* (encryption key) a=* (zero or more media attribute lines)CS 414 - Spring 2011Signaling for IP Telephony Internet Telephone – needs ability of one party to signal to other party to initiate a new call Call – association between a number of participants Note: there is no physical channel or network resources associated with the session layer connection, the connection exists only as signaling state at two end pointsCS 414 - Spring 2011IP Telephony Signaling Protocol(Requirements) Name translations and user location Mapping between names of different levels of abstraction Email address to IP address of host Feature negotiation Group of end systems must agree on what media to exchange ad their respective parameters Different encodings, rates Call Participant Management Invite participants to existing call, transfer call and hold other usersCS 414 - Spring 2011IP Telephony Signaling (Requirements) Feature change Adjust composition of media sessions during the
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