Service/company landscape include 1-1

Size: px
Start display at page:

Download "Service/company landscape include 1-1"

Transcription

1 Service/company landscape include 1-1

2 Applications (3) File transfer Remote login (telnet, rlogin, ssh) World Wide Web (WWW) Instant Messaging (Internet chat, text messaging on cellular phones) Peer-to-Peer file sharing Internet Phone (Voice-Over-IP) Video-on-demand Distributed Games 2

3 Why Study Multimedia Networking? Exciting and fun! Industry-relevant research topic Multimedia is everywhere Lots of open research problems 3

4 4

5 Scalable Content Delivery Motivation Use of Internet for content delivery is massive and becoming more so (e.g., majority of all IP traffic is video content) Variety of approaches: HTTP-based Adaptive Streaming (HAS), broadcast/multicast, batching, replication/caching (e.g. CDNs), P2P, peer-assisted, In these slides, we only provide a few high-level examples 5

6 Service models 6

7 Client-server architecture Client/server model has well-defined roles. client/server server: always-on host permanent IP address server farms for scaling clients: communicate with server may be intermittently connected may have dynamic IP addresses do not communicate directly with each other 7

8 Pure P2P architecture No fixed clients or servers: Each host can act as both client and server at any time no always-on server arbitrary end systems directly communicate peers are intermittently connected and change IP addresses peer-peer 8

9 Additional Multimedia Support Content Distribution Networks (CDNs) Challenging to stream large files (e.g., video) from single origin server in real time Solution: replicate content at hundreds of servers throughout Internet content downloaded to CDN servers ahead of time placing content close to user avoids impairments (loss, delay) of sending content over long paths CDN server typically in edge/access network origin server in North America CDN distribution node CDN server CDN server in S. America CDN server in Asia in Europe 9

10 Additional Multimedia Support Multicast/Broadcast duplicate R1 duplicate creation/transmission R1 R2 R2 duplicate R3 R4 R3 R4 (a) (b) Source-duplication versus in-network duplication. (a) source duplication, (b) in-network duplication Also, application-layer multicast 10

11 11

12 Multimedia Networking Applications Classes of MM applications: 12

13 Multimedia Networking Applications Classes of MM applications: 1) Streaming stored audio and video 2) Streaming live audio and video 3) Real-time interactive audio and video 13

14 Streaming Stored Multimedia (1/2) 1. video recorded 2. video sent network delay 3. video received, played out at client time streaming: at this time, client playing out early part of video, while server still sending later part of video 14

15 Streaming Stored Multimedia (2/2) VCR-like functionality: client can start, stop, pause, rewind, replay, fast-forward, slow-motion, etc. 10 sec initial delay OK 1-2 sec until command effect OK need a separate control protocol? timing constraint for data that is yet to be transmitted: must arrive in time for playback 15

16 Streaming Live Multimedia Examples: Internet radio talk show Live sporting event Streaming playback buffer playback can lag tens of seconds after transmission still have timing constraint Interactivity fast-forward is not possible rewind and pause possible! 16

17 Interactive, Real-time Multimedia applications: IP telephony, video conference, distributed interactive worlds end-end delay requirements: audio: < 150 msec good, < 400 msec OK includes application-layer (packetization) and network delays higher delays noticeable, impair interactivity session initialization callee must advertise its IP address, port number, frame rate, encoding algorithms 17

18 18

19 Multimedia Networking Applications Fundamental characteristics: 19

20 Multimedia Networking Applications Fundamental characteristics: Inherent frame rate Typically delay-sensitive end-to-end delay delay jitter But loss-tolerant: infrequent losses cause minor transient glitches Unlike data apps, which are often delaytolerant but loss-sensitive. 20

21 Multimedia Networking Applications Fundamental characteristics: Inherent frame rate Typically delay-sensitive end-to-end delay delay jitter But loss-tolerant: infrequent losses cause minor transient glitches Unlike data apps, which are often delaytolerant but loss-sensitive. Jitter is the variability of packet delays within the same packet stream 21

22 buffered video Streaming Multimedia: Client Buffering constant bit rate video transmission variable network delay client video reception constant bit rate video playout at client client playout delay time Client-side buffering, playout delay compensate for network-added delay, delay jitter 22

23 Streaming Multimedia: Client Buffering variable fill rate, x(t) constant drain rate, d buffered video Client-side buffering, playout delay compensate for network-added delay, delay jitter 23

24 24

25 Streaming Multimedia: UDP or TCP? UDP server sends at rate appropriate for client (oblivious to network congestion!) often send rate = encoding rate = constant rate then, fill rate = constant rate - packet loss short playout delay (2-5 seconds) to compensate for network delay jitter error recover: time permitting TCP send at maximum possible rate under TCP fill rate fluctuates due to TCP congestion control larger playout delay: smooth TCP delivery rate HTTP/TCP passes more easily through firewalls 25

26 26

27 User Control of Streaming Media: RTSP RTSP: RFC 2326 client-server application layer protocol user control: rewind, fast forward, pause, resume, repositioning, etc. What it doesn t do: doesn t define how audio/video is encapsulated for streaming over network doesn t restrict how streamed media is transported (UDP or TCP possible) doesn t specify how media player buffers audio/video 27

28 A protocol family for streaming RTSP RTP RTCP 28

29 RTSP: out-of-band control FTP uses an out-ofband control channel: file transferred over one TCP connection. control info (directory changes, file deletion, rename) sent over separate TCP connection out-of-band, inband channels use different port numbers RTSP messages (also) sent out-of-band: RTSP control messages use different port numbers than media stream: out-of-band. port 554 media stream is considered in-band. 29

30 RTSP Example Scenario: metafile communicated to web browser browser launches player player sets up an RTSP control connection, data connection to streaming server 30

31 Metafile Example <title>twister</title> <session> </session> <group language=en lipsync> <switch> <track type=audio e="pcmu/8000/1" src = "rtsp://audio.example.com/twister/audio.en/lofi"> <track type=audio e="dvi4/16000/2" pt="90 DVI4/8000/1" src="rtsp://audio.example.com/twister/audio.en/hifi"> </switch> <track type="video/jpeg" </group> src="rtsp://video.example.com/twister/video"> 31

32 RTSP Operation 32

33 RTSP Exchange Example C: SETUP rtsp://audio.example.com/twister/audio RTSP/1.0 Transport: rtp/udp; compression; port=3056; mode=play S: RTSP/ OK Session 4231 C: PLAY rtsp://audio.example.com/twister/audio.en/lofi RTSP/1.0 Session: 4231 Range: npt=0- C: PAUSE rtsp://audio.example.com/twister/audio.en/lofi RTSP/1.0 Session: 4231 Range: npt=37 C: TEARDOWN rtsp://audio.example.com/twister/audio.en/lofi RTSP/1.0 Session: 4231 S: OK 33

34 Real-Time Protocol (RTP) RTP specifies packet structure for packets carrying audio, video data RFC 3550 RTP runs in end systems RTP packets encapsulated in UDP segments 34

35 Real-Time Protocol (RTP) RTP specifies packet structure for packets carrying audio, video data RFC 3550 RTP packet provides payload type identification packet sequence numbering time stamping RTP runs in end systems RTP packets encapsulated in UDP segments interoperability: if two Internet phone applications run RTP, then they may be able to work together 35

36 RTP runs on top of UDP RTP libraries provide transport-layer interface that extends UDP: port numbers, IP addresses payload type identification packet sequence numbering time-stamping 36

37 RTP Example consider sending 64 kbps PCM-encoded voice over RTP. application collects encoded data in chunks, e.g., every 20 msec = 160 bytes in a chunk. audio chunk + RTP header form RTP packet, which is encapsulated in UDP segment RTP header indicates type of audio encoding in each packet sender can change encoding during conference. RTP header also contains sequence numbers, timestamps. 37

38 RTP and QoS RTP does not provide any mechanism to ensure timely data delivery or other QoS guarantees. RTP encapsulation is only seen at end systems (not) by intermediate routers. routers providing best-effort service, making no special effort to ensure that RTP packets arrive at destination in timely matter. 38

39 RTP Header Payload Type (7 bits): Indicates type of encoding currently being used. If sender changes encoding in middle of conference, sender informs receiver via payload type field. Payload type 0: PCM mu-law, 64 kbps Payload type 3, GSM, 13 kbps Payload type 7, LPC, 2.4 kbps Payload type 26, Motion JPEG Payload type 31. H.261 Payload type 33, MPEG2 video Sequence Number (16 bits): Increments by one for each RTP packet sent, and may be used to detect packet loss and to restore packet sequence. 39

40 RTP Header (2) Timestamp field (32 bytes long): sampling instant of first byte in this RTP data packet for audio, timestamp clock typically increments by one for each sampling period (for example, each 125 usecs for 8 KHz sampling clock) if application generates chunks of 160 encoded samples, then timestamp increases by 160 for each RTP packet when source is active. Timestamp clock continues to increase at constant rate when source is inactive. SSRC field (32 bits long): identifies source of t RTP stream. Each stream in RTP session should have distinct SSRC. 40

41 Real-Time Control Protocol (RTCP) works in conjunction with RTP. each participant in RTP session periodically transmits RTCP control packets to all other participants. each RTCP packet contains sender and/or receiver reports report statistics useful to application: # packets sent, # packets lost, interarrival jitter, etc. feedback can be used to control performance sender may modify its transmissions based on feedback 41

42 Real-time Control Protocol (RTCP) Receiver report packets: fraction of packets lost, last sequence number, average interarrival jitter Sender report packets: SSRC of RTP stream, current time, number of packets sent, number of bytes sent RTCP attempts to limit its traffic to 5% of session bandwidth 42

43 Real-time Control Protocol (RTCP) RTCP attempts to limit its traffic to 5% of session bandwidth each RTP session: typically a single multicast address; all RTP /RTCP packets belonging to session use multicast address. RTP, RTCP packets distinguished from each other via distinct port numbers. to limit traffic, each participant reduces RTCP traffic as number of conference participants increases 43

44 RTCP Packets Receiver report packets: fraction of packets lost, last sequence number, average interarrival jitter Sender report packets: SSRC of RTP stream, current time, number of packets sent, number of bytes sent Source description packets: address of sender, sender's name, SSRC of associated RTP stream provide mapping between the SSRC and the user/host name 44

45 Synchronization of Streams RTCP can synchronize different media streams within a RTP session consider videoconferencing app for which each sender generates one RTP stream for video, one for audio. timestamps in RTP packets tied to the video, audio sampling clocks not tied to wall-clock time each RTCP sender-report packet contains (for most recently generated packet in associated RTP stream): timestamp of RTP packet wall-clock time for when packet was created. receivers uses association to synchronize playout of audio, video 45

46 RTCP Bandwidth Scaling RTCP attempts to limit its traffic to 5% of session bandwidth. Example Suppose one sender, sending video at 2 Mbps. Then RTCP attempts to limit its traffic to 100 Kbps. RTCP gives 75% of rate to receivers; remaining 25% to sender 75 kbps is equally shared among receivers: with R receivers, each receiver gets to send RTCP traffic at 75/R kbps. sender gets to send RTCP traffic at 25 kbps. participant determines RTCP packet transmission period by calculating avg RTCP packet size (across entire session) and dividing by allocated rate 46

47 47

48 HTTP-based streaming HTTP-based streaming 4 Allows easy caching, NAT/firewall traversal, etc. Use of TCP provides natural bandwidth adaptation Split into fragments, download sequentially Some support for interactive VoD

49 HTTP-based adaptive streaming (HAS) HTTP-based adaptive streaming 4 Multiple encodings of each fragment (defined in manifest file) Clients adapt quality encoding based on (buffer and network) conditions

50 Chunk-based streaming Chunks begin with keyframe so independent of other chunks Playing chunks in sequence gives seamless video Hybrid of streaming and progressive download: Stream-like: sequence of small chunks requested as needed Progressive download-like: HTTP transfer mechanism, stateless servers 50

51 Example 51 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Server

52 Example 52 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Server

53 Example 53 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Server

54 Example 54 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Server

55 Example 55 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Server

56 Example 56 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Server

57 Example 57 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Server

58 Example 58 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Server

59 HTTP-based Adaptive Streaming (HAS) Other terms for similar concepts: Adaptive Streaming, Smooth Streaming, HTTP Chunking Probably most important is return to stateless server and TCP basis of 1st generation Actually a series of small progressive downloads of chunks (or range requests) No standard protocol... 59

60 HTTP-based Adaptive Streaming (HAS) Other terms for similar concepts: Adaptive Streaming, Smooth Streaming, HTTP Chunking Probably most important is return to stateless server and TCP basis of 1st generation Actually a series of small progressive downloads of chunks (or range requests) No standard protocol... Apple HLS: HTTP Live Streaming Microsoft IIS Smooth Streaming: part of Silverlight Adobe: Flash Dynamic Streaming DASH: Dynamic Adaptive Streaming over HTTP 60

61 Example players Player Container Type Open Source Microsoft Smooth Streaming Netflix player Silverlight Silverlight Chunk Range Apple HLS QuickTime Chunk Adobe HDS Flash Chunk 61

62 Problem: Proxyassisted HAS Slides from: V. Krishnamoorthi et al. "Helping Hand or Hidden Hurdle: Proxy-assisted HTTP-based Adaptive Streaming Performance", Proc. IEEE MASCOTS, 2013 Clients want High playback quality Small stall times Few buffer interruptions Few quality switches 62

63 Problem: Proxyassisted HAS Slides from: V. Krishnamoorthi et al. "Helping Hand or Hidden Hurdle: Proxy-assisted HTTP-based Adaptive Streaming Performance", Proc. IEEE MASCOTS, 2013 Clients want High playback quality Small stall times Few buffer interruptions Few quality switches HAS is increasingly responsible for larger traffic volumes Network and service providers may consider integrating HASaware proxy policies 63

64 Problem: Proxyassisted HAS Slides from: V. Krishnamoorthi et al. "Helping Hand or Hidden Hurdle: Proxy-assisted HTTP-based Adaptive Streaming Performance", Proc. IEEE MASCOTS, 2013 Clients want High playback quality Small stall times Few buffer interruptions Few quality switches Network providers want High QoE of customers/clients 64

65 Problem: Proxyassisted HAS Clients want High playback quality Small stall times Few buffer interruptions Few quality switches Network providers want High QoE of customers/clients Low bandwidth usage High hit rate 65

66 Problem: Proxyassisted HAS Clients want High playback quality Small stall times Few buffer interruptions Few quality switches Network providers want High QoE of customers/clients Low bandwidth usage High hit rate 66

67 Problem: Proxyassisted HAS In this paper Evaluation of proxy-assisted HAS policies 67

68 Problem: Proxyassisted HAS In this paper Evaluation of proxy-assisted HAS policies 68

69 Problem: Proxyassisted HAS In this paper Evaluation of proxy-assisted HAS policies 69

70 Problem: Proxyassisted HAS In this paper Evaluation of proxy-assisted HAS policies 70

71 Problem: Proxyassisted HAS In this paper Evaluation of proxy-assisted HAS policies 71

72 Example: Default best-effort 72

73 Example: Default best-effort 73 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client Proxy

74 Example: Default best-effort 74 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 1 Proxy before 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Proxy after

75 Example: Default best-effort 75 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 1 Proxy before 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Proxy after

76 Example: Default best-effort 76 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 2 Proxy before 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Proxy after

77 Example: Default best-effort 77 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 2 Proxy before 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Proxy after

78 Example: Default best-effort 78 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 3 Proxy before 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Proxy after

79 Example: Default best-effort 79 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Client 3 Proxy before 1,4 1,3 1,2 1,1 2,4 2,3 2,2 2,1 3,4 3,3 3,2 3,1 4,4 4,3 4,2 4,1 5,4 5,3 5,2 5,1 6,4 6,3 6,2 6,1 7,4 7,3 7,2 7,1 Proxy after

80 80

81 Multimedia Over Best Effort Internet TCP/UDP/IP: no guarantees on delay, loss??????? But you said multimedia apps requires QoS and level of performance to be effective!???? Today s multimedia applications implement functionality at the app. layer to mitigate (as best possible) effects of delay, loss 81

82 Packet Loss network loss: IP datagram lost due to network congestion (router buffer overflow) or losses at wireless link(s) delay loss: IP datagram arrives too late for playout at receiver (effectively the same as if it was lost) delays: processing, queueing in network; endsystem (sender, receiver) delays Tolerable delay depends on the application How can packet loss be handled? We will discuss this next 82

83 Receiver-based Packet Loss Recovery Generate replacement packet Packet repetition Interpolation Other sophisticated schemes Works when audio/video streams exhibit short-term correlations (e.g., self-similarity) Works for relatively low loss rates (e.g., < 5%) Typically, breaks down on bursty losses 83

84 Forward Error Correction (FEC) For every group of n actual media packets, generate k additional redundant packets Send out n+k packets, which increases the bandwidth consumption by factor k/n. Receiver can reconstruct the original n media packets provided at most k packets are lost from the group Works well at high loss rates (for a proper choice of k) Handles bursty packet losses Cost: increase in transmission cost (bandwidth) 84

85 Another FEC Example piggyback lower quality stream Example: send lower resolution audio stream as the redundant information Whenever there is non-consecutive loss, the receiver can conceal the loss. Can also append (n-1)st and (n-2)nd low-bit rate chunk 85

86 Interleaving: Recovery from packet loss Interleaving Intentionally alter the sequence of packets before transmission Better robustness against burst losses of packets Results in increased playout delay from inter-leaving 86

87 Summary: Internet MM tricks of the trade UDP vs TCP client-side adaptive playout delay: to compensate for delay server side matches stream bandwidth to available client-to-server path bandwidth chose among pre-encoded stream rates dynamic server encoding rate error recovery (on top of UDP) at the app layer FEC, interleaving retransmissions, time permitting conceal errors: repeat nearby data 87

88 88

89 More slides 89

90 Some more on QoS: Real-time traffic support Hard real-time Soft real-time Guarantee bounded delay Guarantee delay jitter End-to-end delay = queuing delays + transmission delays + processing times + propagation delay (and any potential retransmission delays at lower layers) 90

91 How to provide better support for Multimedia? (1/4) Integrated Services (IntServ) philosophy: architecture for providing QoS guarantees in IP networks for individual flows requires fundamental changes in Internet design so that apps can reserve end-to-end bandwidth Components of this architecture are Reservation protocol (e.g., RSVP) Admission control Routing protocol (e.g., QoS-aware) Packet classifier and route selection Packet scheduler (e.g., priority, deadline-based) 91

92 How to provide better support for Multimedia? (2/4) Concerns with IntServ: Scalability: signaling, maintaining per-flow router state difficult with thousands/millions of flows Flexible Service Models: IntServ has only two classes. Desire qualitative service classes E.g., Courier, ExpressPost, and normal mail E.g., First, business, and economy class Differentiated Services (DiffServ) approach: simple functions in network core, relatively complex functions at edge routers (or hosts) Don t define the service classes, just provide functional components to build service classes 92

Outline. QoS routing in ad-hoc networks. Real-time traffic support. Classification of QoS approaches. QoS design choices

Outline. QoS routing in ad-hoc networks. Real-time traffic support. Classification of QoS approaches. QoS design choices Outline QoS routing in ad-hoc networks QoS in ad-hoc networks Classifiction of QoS approaches Instantiation in IEEE 802.11 The MAC protocol (recap) DCF, PCF and QoS support IEEE 802.11e: EDCF, HCF Streaming

More information

Multimedia Networking

Multimedia Networking Multimedia Networking 1 Multimedia, Quality of Service (QoS): What is it? Multimedia applications: Network audio and video ( continuous media ) QoS Network provides application with level of performance

More information

Including location-based services, IoT, and increasing personalization... Service models and delivery architectures

Including location-based services, IoT, and increasing personalization... Service models and delivery architectures Outline Service landscape Example services Including location-based services, IoT, and increasing personalization... Service models and delivery architectures Client-server, p2p, one-to-many E.g., middleboxes/proxies,

More information

Digital Asset Management 5. Streaming multimedia

Digital Asset Management 5. Streaming multimedia Digital Asset Management 5. Streaming multimedia 2015-10-29 Keys of Streaming Media Algorithms (**) Standards (*****) Complete End-to-End systems (***) Research Frontiers(*) Streaming... Progressive streaming

More information

Chapter 7 Multimedia Networking

Chapter 7 Multimedia Networking Chapter 7 Multimedia Networking Principles Classify multimedia applications Identify the network services and the requirements the apps need Making the best of best effort service Mechanisms for providing

More information

Mohammad Hossein Manshaei 1393

Mohammad Hossein Manshaei 1393 Mohammad Hossein Manshaei manshaei@gmail.com 1393 Voice and Video over IP Slides derived from those available on the Web site of the book Computer Networking, by Kurose and Ross, PEARSON 2 Multimedia networking:

More information

MULTIMEDIA I CSC 249 APRIL 26, Multimedia Classes of Applications Services Evolution of protocols

MULTIMEDIA I CSC 249 APRIL 26, Multimedia Classes of Applications Services Evolution of protocols MULTIMEDIA I CSC 249 APRIL 26, 2018 Multimedia Classes of Applications Services Evolution of protocols Streaming from web server Content distribution networks VoIP Real time streaming protocol 1 video

More information

CS640: Introduction to Computer Networks. Application Classes. Application Classes (more) 11/20/2007

CS640: Introduction to Computer Networks. Application Classes. Application Classes (more) 11/20/2007 CS640: Introduction to Computer Networks Aditya Akella Lecture 21 - Multimedia Networking Application Classes Typically sensitive to delay, but can tolerate packet loss (would cause minor glitches that

More information

Streaming (Multi)media

Streaming (Multi)media Streaming (Multi)media Overview POTS, IN SIP, H.323 Circuit Switched Networks Packet Switched Networks 1 POTS, IN SIP, H.323 Circuit Switched Networks Packet Switched Networks Circuit Switching Connection-oriented

More information

Latency and Loss Requirements! Receiver-side Buffering! Dealing with Loss! Loss Recovery!

Latency and Loss Requirements! Receiver-side Buffering! Dealing with Loss! Loss Recovery! Cumulative data! Latency and Loss Requirements! Fundamental characteristics of multimedia applications:! Typically delay sensitive!! live audio < 150 msec end-to-end delay is not perceptible!! 150-400

More information

Lecture 9: Media over IP

Lecture 9: Media over IP Lecture 9: Media over IP These slides are adapted from the slides provided by the authors of the book (to the right), available from the publisher s website. Computer Networking: A Top Down Approach 5

More information

Computer Networks. Instructor: Niklas Carlsson

Computer Networks. Instructor: Niklas Carlsson Computer Networks Instructor: Niklas Carlsson Email: niklas.carlsson@liu.se Notes derived from Computer Networking: A Top Down Approach, by Jim Kurose and Keith Ross, Addison-Wesley. The slides are adapted

More information

Multimedia in the Internet

Multimedia in the Internet Protocols for multimedia in the Internet Andrea Bianco Telecommunication Network Group firstname.lastname@polito.it http://www.telematica.polito.it/ > 4 4 3 < 2 Applications and protocol stack DNS Telnet

More information

Video Streaming and Media Session Protocols

Video Streaming and Media Session Protocols Video Streaming and Media Session Protocols 1 Streaming Stored Multimedia Stored media streaming File containing digitized audio / video Stored at source Transmitted to client Streaming Client playout

More information

Quality of Service. Qos Mechanisms. EECS 122: Lecture 15

Quality of Service. Qos Mechanisms. EECS 122: Lecture 15 Quality of Service EECS 122: Lecture 15 Department of Electrical Engineering and Computer Sciences University of California Berkeley Qos Mechanisms Policing at the edge of the network controls the amount

More information

Today. March 7, 2006 EECS122 Lecture 15 (AKP) 4. D(t) Scheduling Discipline. March 7, 2006 EECS122 Lecture 15 (AKP) 5

Today. March 7, 2006 EECS122 Lecture 15 (AKP) 4. D(t) Scheduling Discipline. March 7, 2006 EECS122 Lecture 15 (AKP) 5 Today Quality of Service EECS 122: Lecture 15 Department of Electrical Engineering and Computer Sciences University of California Berkeley End to End QoS Network Layer: Multiple routers Intserv Diffserv

More information

Multimedia Applications: Streaming. Hamid R. Rabiee Mostafa Salehi, Fatemeh Dabiran, Hoda Ayatollahi Spring 2011

Multimedia Applications: Streaming. Hamid R. Rabiee Mostafa Salehi, Fatemeh Dabiran, Hoda Ayatollahi Spring 2011 Multimedia Applications: Streaming Hamid R. Rabiee Mostafa Salehi, Fatemeh Dabiran, Hoda Ayatollahi Spring 2011 Outline What is Streaming Technology? Issues in Video Streaming over the Internet Bandwidth

More information

Computer Networks. Wenzhong Li. Nanjing University

Computer Networks. Wenzhong Li. Nanjing University Computer Networks Wenzhong Li Nanjing University 1 Chapter 5. End-to-End Protocols Transport Services and Mechanisms User Datagram Protocol (UDP) Transmission Control Protocol (TCP) TCP Congestion Control

More information

The Transport Layer: User Datagram Protocol

The Transport Layer: User Datagram Protocol The Transport Layer: User Datagram Protocol CS7025: Network Technologies and Server Side Programming http://www.scss.tcd.ie/~luzs/t/cs7025/ Lecturer: Saturnino Luz April 4, 2011 The UDP All applications

More information

Multimedia Networking

Multimedia Networking CMPT765/408 08-1 Multimedia Networking 1 Overview Multimedia Networking The note is mainly based on Chapter 7, Computer Networking, A Top-Down Approach Featuring the Internet (4th edition), by J.F. Kurose

More information

Multimedia Applications. Classification of Applications. Transport and Network Layer

Multimedia Applications. Classification of Applications. Transport and Network Layer Chapter 2: Representation of Multimedia Data Chapter 3: Multimedia Systems Communication Aspects and Services Multimedia Applications and Communication Protocols Quality of Service and Resource Management

More information

in the Internet Andrea Bianco Telecommunication Network Group Application taxonomy

in the Internet Andrea Bianco Telecommunication Network Group  Application taxonomy Multimedia traffic support in the Internet Andrea Bianco Telecommunication Network Group firstname.lastname@polito.it http://www.telematica.polito.it/ Network Management and QoS Provisioning - 1 Application

More information

Chapter 7: Multimedia Networking

Chapter 7: Multimedia Networking Chapter 7: Multimedia Networking Multimedia and Quality of Service: What is it multimedia : network audio and video ( continuous media ) A note on the use of these ppt slides: We re making these slides

More information

CSC 4900 Computer Networks: Multimedia Applications

CSC 4900 Computer Networks: Multimedia Applications CSC 4900 Computer Networks: Multimedia Applications Professor Henry Carter Fall 2017 Last Time What is a VPN? What technology/protocol suite is generally used to implement them? How much protection does

More information

Mohammad Hossein Manshaei 1393

Mohammad Hossein Manshaei 1393 Mohammad Hossein Manshaei manshaei@gmail.com 1393 Voice and Video over IP Slides derived from those available on the Web site of the book Computer Networking, by Kurose and Ross, PEARSON 2 multimedia applications:

More information

Chapter 7 Multimedia Networking

Chapter 7 Multimedia Networking Chapter 7 Multimedia Networking A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify,

More information

Chapter 9. Multimedia Networking. Computer Networking: A Top Down Approach

Chapter 9. Multimedia Networking. Computer Networking: A Top Down Approach Chapter 9 Multimedia Networking A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the animations;

More information

CSCD 433/533 Advanced Networks Fall Lecture 14 RTSP and Transport Protocols/ RTP

CSCD 433/533 Advanced Networks Fall Lecture 14 RTSP and Transport Protocols/ RTP CSCD 433/533 Advanced Networks Fall 2012 Lecture 14 RTSP and Transport Protocols/ RTP 1 Topics Multimedia Player RTSP Review RTP Real Time Protocol Requirements for RTP RTP Details Applications that use

More information

File transfer. Internet Applications (FTP,WWW, ) Connections. Data connections

File transfer. Internet Applications (FTP,WWW,  ) Connections. Data connections File transfer Internet Applications (FTP,WWW, Email) File transfer protocol (FTP) is used to transfer files from one host to another Handles all sorts of data files Handles different conventions used in

More information

Multimedia networking: outline

Multimedia networking: outline Multimedia networking: outline 7.1 multimedia networking applications 7.2 streaming stored video 7.3 voice-over-ip 7.4 protocols for real-time conversational applications: RTP, SIP 7.5 network support

More information

Multimedia Networking

Multimedia Networking Multimedia Networking #2 Multimedia Networking Semester Ganjil 2012 PTIIK Universitas Brawijaya #2 Multimedia Applications 1 Schedule of Class Meeting 1. Introduction 2. Applications of MN 3. Requirements

More information

Chapter 7 Multimedia Networking

Chapter 7 Multimedia Networking Chapter 7 Multimedia Networking A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify,

More information

Multimedia Networking

Multimedia Networking Multimedia Networking Raj Jain Washington University in Saint Louis Saint Louis, MO 63130 Jain@wustl.edu Audio/Video recordings of this lecture are available on-line at: http://www.cse.wustl.edu/~jain/cse473-09/

More information

CS 218 F Nov 3 lecture: Streaming video/audio Adaptive encoding (eg, layered encoding) TCP friendliness. References:

CS 218 F Nov 3 lecture: Streaming video/audio Adaptive encoding (eg, layered encoding) TCP friendliness. References: CS 218 F 2003 Nov 3 lecture: Streaming video/audio Adaptive encoding (eg, layered encoding) TCP friendliness References: J. Padhye, V.Firoiu, D. Towsley, J. Kurose Modeling TCP Throughput: a Simple Model

More information

Tema 0: Transmisión de Datos Multimedia

Tema 0: Transmisión de Datos Multimedia Tema 0: Transmisión de Datos Multimedia Clases de aplicaciones multimedia Redes basadas en IP y QoS Computer Networking: A Top Down Approach Featuring the Internet, 3 rd edition. Jim Kurose, Keith Ross

More information

ITTC Communication Networks The University of Kansas EECS 780 Multimedia and Session Control

ITTC Communication Networks The University of Kansas EECS 780 Multimedia and Session Control Communication Networks The University of Kansas EECS 780 Multimedia and Session Control James P.G. Sterbenz Department of Electrical Engineering & Computer Science Information Technology & Telecommunications

More information

Chapter 9. Multimedia Networking. Computer Networking: A Top Down Approach

Chapter 9. Multimedia Networking. Computer Networking: A Top Down Approach Chapter 9 Multimedia Networking A note on the use of these Powerpoint slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the animations;

More information

Page 1. Outline / Computer Networking : 1 st Generation Commercial PC/Packet Video Technologies

Page 1. Outline / Computer Networking : 1 st Generation Commercial PC/Packet Video Technologies Outline 15-441/15-641 Computer Networking Lecture 18 Internet Video Delivery Peter Steenkiste Slides by Professor Hui Zhang Background Technologies: - HTTP download - Real-time streaming - HTTP streaming

More information

Internet Video Delivery. Professor Hui Zhang

Internet Video Delivery. Professor Hui Zhang 18-345 Internet Video Delivery Professor Hui Zhang 1 1990 2004: 1 st Generation Commercial PC/Packet Video Technologies Simple video playback, no support for rich app Not well integrated with Web browser

More information

Real-Time Control Protocol (RTCP)

Real-Time Control Protocol (RTCP) Real-Time Control Protocol (RTCP) works in conjunction with RTP each participant in RTP session periodically sends RTCP control packets to all other participants each RTCP packet contains sender and/or

More information

CS 457 Multimedia Applications. Fall 2014

CS 457 Multimedia Applications. Fall 2014 CS 457 Multimedia Applications Fall 2014 Topics Digital audio and video Sampling, quantizing, and compressing Multimedia applications Streaming audio and video for playback Live, interactive audio and

More information

Multimedia! 23/03/18. Part 3: Lecture 3! Content and multimedia! Internet traffic!

Multimedia! 23/03/18. Part 3: Lecture 3! Content and multimedia! Internet traffic! Part 3: Lecture 3 Content and multimedia Internet traffic Multimedia How can multimedia be transmitted? Interactive/real-time Streaming 1 Voice over IP Interactive multimedia Voice and multimedia sessions

More information

Part 3: Lecture 3! Content and multimedia!

Part 3: Lecture 3! Content and multimedia! Part 3: Lecture 3! Content and multimedia! Internet traffic! Multimedia! How can multimedia be transmitted?! Interactive/real-time! Streaming! Interactive multimedia! Voice over IP! Voice and multimedia

More information

Data Communications & Networks. Session 10 Main Theme Multimedia Networking. Dr. Jean-Claude Franchitti

Data Communications & Networks. Session 10 Main Theme Multimedia Networking. Dr. Jean-Claude Franchitti Data Communications & Networks Session 10 Main Theme Multimedia Networking Dr. Jean-Claude Franchitti New York University Computer Science Department Courant Institute of Mathematical Sciences Adapted

More information

Multimedia Networking

Multimedia Networking CE443 Computer Networks Multimedia Networking Behnam Momeni Computer Engineering Department Sharif University of Technology Acknowledgments: Lecture slides are from Computer networks course thought by

More information

Chapter 7 Multimedia Networking. Chapter 7 outline. Chapter 7: goals. Multimedia and Quality of Service: What is it? QoS

Chapter 7 Multimedia Networking. Chapter 7 outline. Chapter 7: goals. Multimedia and Quality of Service: What is it? QoS Chapter 7 Multimedia Networking Multimedia and Quality of Service: What is it? multimedia applications: network audio and video ( continuous media ) A note on the use of these ppt slides: We re making

More information

Real-Time Protocol (RTP)

Real-Time Protocol (RTP) Real-Time Protocol (RTP) Provides standard packet format for real-time application Typically runs over UDP Specifies header fields below Payload Type: 7 bits, providing 128 possible different types of

More information

55:054 Communication Networks 12/11/2008

55:054 Communication Networks 12/11/2008 Chapter 7 Multimedia Networking Multimedia and Quality of Service: What is it? multimedia applications: network audio and video ( continuous media ) All material copyright 1996-2007 J.F Kurose and K.W.

More information

Chapter 7 Multimedia Networking

Chapter 7 Multimedia Networking Chapter 7 Multimedia Networking Computer Networking: A Top Down Approach Featuring the Internet, 3 rd edition. Jim Kurose, Keith Ross Addison-Wesley, July 2004. 7: Multimedia Networking 7-1 Multimedia,

More information

Chapter 28. Multimedia

Chapter 28. Multimedia Chapter 28. Multimedia 28-1 Internet Audio/Video Streaming stored audio/video refers to on-demand requests for compressed audio/video files Streaming live audio/video refers to the broadcasting of radio

More information

RTP: A Transport Protocol for Real-Time Applications

RTP: A Transport Protocol for Real-Time Applications RTP: A Transport Protocol for Real-Time Applications Provides end-to-end delivery services for data with real-time characteristics, such as interactive audio and video. Those services include payload type

More information

Multimedia

Multimedia Multimedia Communications @CS.NCTU Lecture 11: Multimedia Networking Instructor: Kate Ching-Ju Lin ( 林靖茹 ) 2 Why Multimedia Networking Matters? Watching video over Internet Uploading user-generated content

More information

Chapter 7 + ATM/VC networks (3, 4, 5): Multimedia networking, QoS, Congestion control Course on Computer Communication and Networks, CTH/GU

Chapter 7 + ATM/VC networks (3, 4, 5): Multimedia networking, QoS, Congestion control Course on Computer Communication and Networks, CTH/GU Chapter 7 + ATM/VC networks (3, 4, 5): Multimedia networking, QoS, Congestion control Course on Computer Communication and Networks, CTH/GU The slides are adaptation of the slides made available by the

More information

4 rd class Department of Network College of IT- University of Babylon

4 rd class Department of Network College of IT- University of Babylon 1. INTRODUCTION We can divide audio and video services into three broad categories: streaming stored audio/video, streaming live audio/video, and interactive audio/video. Streaming means a user can listen

More information

Networking Applications

Networking Applications Networking Dr. Ayman A. Abdel-Hamid College of Computing and Information Technology Arab Academy for Science & Technology and Maritime Transport Multimedia Multimedia 1 Outline Audio and Video Services

More information

Chapter 7 Multimedia Networking

Chapter 7 Multimedia Networking Chapter 7 Multimedia Networking A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify,

More information

Content distribution networks

Content distribution networks Content distribution networks v challenge: how to stream content (selected from millions of videos) to hundreds of thousands of simultaneous users? v option 2: store/serve multiple copies of videos at

More information

Telematics 2 & Performance Evaluation

Telematics 2 & Performance Evaluation Telematics 2 & Performance Evaluation Chapter 1 Multimedia 1 Multimedia, Quality of Service: What is it? Multimedia applications: network audio and video ( continuous media ) QoS Network provides application

More information

Chapter 7 + ATM/VC networks (3, 4, 5): control Course on Computer Communication and Networks, CTH/GU

Chapter 7 + ATM/VC networks (3, 4, 5): control Course on Computer Communication and Networks, CTH/GU Chapter 7 + ATM/VC networks (3, 4, 5): Multimedia networking, QoS, Congestion control Course on Computer Communication and Networks, CTH/GU The slides are adaptation of the slides made available by the

More information

ETSF10 Internet Protocols Transport Layer Protocols

ETSF10 Internet Protocols Transport Layer Protocols ETSF10 Internet Protocols Transport Layer Protocols 2012, Part 2, Lecture 2.2 Kaan Bür, Jens Andersson Transport Layer Protocols Special Topic: Quality of Service (QoS) [ed.4 ch.24.1+5-6] [ed.5 ch.30.1-2]

More information

Lecture 14: Multimedia Communications

Lecture 14: Multimedia Communications Lecture 14: Multimedia Communications Prof. Shervin Shirmohammadi SITE, University of Ottawa Fall 2005 CEG 4183 14-1 Multimedia Characteristics Bandwidth Media has natural bitrate, not very flexible. Packet

More information

Multimedia networking: outline

Multimedia networking: outline Multimedia networking: outline 7.1 multimedia networking applications 7.2 streaming stored video 7.3 voice-over-ip 7.4 protocols for real-time conversational applications 7.5 network support for multimedia

More information

Week 7: Traffic Models and QoS

Week 7: Traffic Models and QoS Week 7: Traffic Models and QoS Acknowledgement: Some slides are adapted from Computer Networking: A Top Down Approach Featuring the Internet, 2 nd edition, J.F Kurose and K.W. Ross All Rights Reserved,

More information

Kommunikationssysteme [KS]

Kommunikationssysteme [KS] Kommunikationssysteme [KS] Dr.-Ing. Falko Dressler Computer Networks and Communication Systems Department of Computer Sciences University of Erlangen-Nürnberg http://www7.informatik.uni-erlangen.de/~dressler/

More information

Transport protocols Introduction

Transport protocols Introduction Transport protocols 12.1 Introduction All protocol suites have one or more transport protocols to mask the corresponding application protocols from the service provided by the different types of network

More information

Lecture 11. Transport Layer (cont d) Transport Layer 1

Lecture 11. Transport Layer (cont d) Transport Layer 1 Lecture 11 Transport Layer (cont d) Transport Layer 1 Agenda The Transport Layer (continue) Connection-oriented Transport (TCP) Flow Control Connection Management Congestion Control Introduction to the

More information

Multimedia Applications over Packet Networks

Multimedia Applications over Packet Networks Multimedia Networking and Quality of Service Mario Baldi Technical Univeristy of Torino Computer Engineering Department mario.baldi@polito.it +39 011 564 7067 staff.polito.it/mario.baldi Nota di Copyright

More information

Chapter 5 VoIP. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March Multmedia Networking

Chapter 5 VoIP. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March Multmedia Networking Chapter 5 VoIP Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 Multmedia Networking audio signal amplitude Multimedia: audio analog audio signal sampled

More information

Multimedia networking: outline

Multimedia networking: outline Computer Network Architectures and Multimedia Guy Leduc Chapter 4 Multimedia Applications & Transport Sections 9.1 to 9.4 from Computer Networking: A Top Down Approach, 7 th edition. Jim Kurose, Keith

More information

Chapter 7 Multimedia Networking

Chapter 7 Multimedia Networking Chapter 7 Multimedia Networking A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you see the animations;

More information

RTP. Prof. C. Noronha RTP. Real-Time Transport Protocol RFC 1889

RTP. Prof. C. Noronha RTP. Real-Time Transport Protocol RFC 1889 RTP Real-Time Transport Protocol RFC 1889 1 What is RTP? Primary objective: stream continuous media over a best-effort packet-switched network in an interoperable way. Protocol requirements: Payload Type

More information

CMSC 322 Computer Networks Applications and End-To- End

CMSC 322 Computer Networks Applications and End-To- End CMSC 322 Computer Networks Applications and End-To- End Professor Doug Szajda CMSC 332: Computer Networks Announcements Project 2 has been posted and is due Monday, February 8 (No extension!) Homework

More information

Real-time Services BUPT/QMUL

Real-time Services BUPT/QMUL Real-time Services BUPT/QMUL 2017-05-27 Agenda Real-time services over Internet Real-time transport protocols RTP (Real-time Transport Protocol) RTCP (RTP Control Protocol) Multimedia signaling protocols

More information

Internet Streaming Media. Reji Mathew NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2006

Internet Streaming Media. Reji Mathew NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2006 Internet Streaming Media Reji Mathew NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2006 Multimedia Streaming UDP preferred for streaming System Overview Protocol stack Protocols RTP + RTCP SDP RTSP SIP

More information

Introduction to Networked Multimedia An Introduction to RTP p. 3 A Brief History of Audio/Video Networking p. 4 Early Packet Voice and Video

Introduction to Networked Multimedia An Introduction to RTP p. 3 A Brief History of Audio/Video Networking p. 4 Early Packet Voice and Video Preface p. xi Acknowledgments p. xvii Introduction to Networked Multimedia An Introduction to RTP p. 3 A Brief History of Audio/Video Networking p. 4 Early Packet Voice and Video Experiments p. 4 Audio

More information

Multimedia Networking. Network Support for Multimedia Applications

Multimedia Networking. Network Support for Multimedia Applications Multimedia Networking Network Support for Multimedia Applications Protocols for Real Time Interactive Applications Differentiated Services (DiffServ) Per Connection Quality of Services Guarantees (IntServ)

More information

OSI Transport Layer. Network Fundamentals Chapter 4. Version Cisco Systems, Inc. All rights reserved. Cisco Public 1

OSI Transport Layer. Network Fundamentals Chapter 4. Version Cisco Systems, Inc. All rights reserved. Cisco Public 1 OSI Transport Layer Network Fundamentals Chapter 4 Version 4.0 1 Transport Layer Role and Services Transport layer is responsible for overall end-to-end transfer of application data 2 Transport Layer Role

More information

Multimedia Networking and Quality of Service

Multimedia Networking and Quality of Service Multimedia Networking and Quality of Service Mario Baldi Politecnico di Torino (Technical Univeristy of Torino) Department of Computer Engineering mario.baldi [at] polito.it +39 011 564 7067 staff.polito.it/mario.baldi

More information

Introduction to LAN/WAN. Application Layer 4

Introduction to LAN/WAN. Application Layer 4 Introduction to LAN/WAN Application Layer 4 Multimedia Multimedia: Audio + video Human ear: 20Hz 20kHz, Dogs hear higher freqs DAC converts audio waves to digital E.g PCM uses 8-bit samples 8000 times

More information

Multimedia Protocols. Foreleser: Carsten Griwodz Mai INF-3190: Multimedia Protocols

Multimedia Protocols. Foreleser: Carsten Griwodz Mai INF-3190: Multimedia Protocols Multimedia Protocols Foreleser: Carsten Griwodz Email: griff@ifi.uio.no 11. Mai 2006 1 INF-3190: Multimedia Protocols Media! Medium: "Thing in the middle! here: means to distribute and present information!

More information

Module objectives. Integrated services. Support for real-time applications. Real-time flows and the current Internet protocols

Module objectives. Integrated services. Support for real-time applications. Real-time flows and the current Internet protocols Integrated services Reading: S. Keshav, An Engineering Approach to Computer Networking, chapters 6, 9 and 4 Module objectives Learn and understand about: Support for real-time applications: network-layer

More information

Quality of Service (QoS)

Quality of Service (QoS) Quality of Service (QoS) A note on the use of these ppt slides: We re making these slides freely available to all (faculty, students, readers). They re in PowerPoint form so you can add, modify, and delete

More information

Multimedia: video ... frame i+1

Multimedia: video ... frame i+1 Multimedia: video video: sequence of images displayed at constant rate e.g. 24 images/sec digital image: array of pixels each pixel represented by bits coding: use redundancy within and between images

More information

CSC 401 Data and Computer Communications Networks

CSC 401 Data and Computer Communications Networks CSC 401 Data and Computer Communications Networks Application Layer Video Streaming, CDN and Sockets Sec 2.6 2.7 Prof. Lina Battestilli Fall 2017 Outline Application Layer (ch 2) 2.1 principles of network

More information

Multimedia Networking. Protocols for Real-Time Interactive Applications

Multimedia Networking. Protocols for Real-Time Interactive Applications Multimedia Networking Protocols for Real-Time Interactive Applications Real Time Protocol Real Time Control Protocol Session Initiation Protocol H.323 Real-Time Protocol (RTP) RTP is companion protocol

More information

Week-12 (Multimedia Networking)

Week-12 (Multimedia Networking) Computer Networks and Applications COMP 3331/COMP 9331 Week-12 (Multimedia Networking) 1 Multimedia: audio analog audio signal sampled at constant rate telephone: 8,000 samples/sec CD music: 44,100 samples/sec

More information

CS519: Computer Networks. Lecture 9: May 03, 2004 Media over Internet

CS519: Computer Networks. Lecture 9: May 03, 2004 Media over Internet : Computer Networks Lecture 9: May 03, 2004 Media over Internet Media over the Internet Media = Voice and Video Key characteristic of media: Realtime Which we ve chosen to define in terms of playback,

More information

Advanced Networking Technologies

Advanced Networking Technologies Advanced Networking Technologies Chapter 13 Caching Techniques for Streaming Media (Acknowledgement: These slides have been prepared by Dr.-Ing. Markus Hofmann) 1 What is Streaming? Streaming media refers

More information

Multimedia networked applications: standards, protocols and research trends

Multimedia networked applications: standards, protocols and research trends Multimedia networked applications: standards, protocols and research trends Maria Teresa Andrade FEUP / INESC Porto mandrade@fe.up.pt ; maria.andrade@inescporto.pt http://www.fe.up.pt/~mandrade/ ; http://www.inescporto.pt

More information

Transporting Voice by Using IP

Transporting Voice by Using IP Transporting Voice by Using IP Voice over UDP, not TCP Speech Small packets, 10 40 ms Occasional packet loss is not a catastrophe Delay-sensitive TCP: connection set-up, ack, retransmit delays 5 % packet

More information

Goal and A sample Network App

Goal and A sample Network App Application Layer Goal and A sample Network App Write programs that run on different end systems and communicate over a network. e.g., Web: Web server software communicates with browser software Little

More information

Real-time Services BUPT/QMUL

Real-time Services BUPT/QMUL Real-time Services BUPT/QMUL 2015-06-02 Agenda Real-time services over Internet Real-time transport protocols RTP (Real-time Transport Protocol) RTCP (RTP Control Protocol) Multimedia signaling protocols

More information

Cobalt Digital Inc Galen Drive Champaign, IL USA

Cobalt Digital Inc Galen Drive Champaign, IL USA Cobalt Digital White Paper IP Video Transport Protocols Knowing What To Use When and Why Cobalt Digital Inc. 2506 Galen Drive Champaign, IL 61821 USA 1-217-344-1243 www.cobaltdigital.com support@cobaltdigital.com

More information

CSC 4900 Computer Networks: End-to-End Design

CSC 4900 Computer Networks: End-to-End Design CSC 4900 Computer Networks: End-to-End Design Professor Henry Carter Fall 2017 Villanova University Department of Computing Sciences Review In the last two lectures, we discussed the fundamentals of networking

More information

Transporting audio-video. over the Internet

Transporting audio-video. over the Internet Transporting audio-video over the Internet Key requirements Bit rate requirements Audio requirements Video requirements Delay requirements Jitter Inter-media synchronization On compression... TCP, UDP

More information

Internet Streaming Media. Reji Mathew NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2007

Internet Streaming Media. Reji Mathew NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2007 Internet Streaming Media Reji Mathew NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2007 Multimedia Streaming UDP preferred for streaming System Overview Protocol stack Protocols RTP + RTCP SDP RTSP SIP

More information

Internet Streaming Media

Internet Streaming Media Multimedia Streaming Internet Streaming Media Reji Mathew NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2006 preferred for streaming System Overview Protocol stack Protocols + SDP SIP Encoder Side Issues

More information

Lec 17 Multimedia Transport: RTP, TCP/HTTP and QUIC

Lec 17 Multimedia Transport: RTP, TCP/HTTP and QUIC Multimedia Communication Lec 17 Multimedia Transport: RTP, TCP/HTTP and QUIC Zhu Li Course Web: http://l.web.umkc.edu/lizhu/teaching/2016sp.video-communication/main.html Z. Li, Multimedia Communciation,

More information

Popular protocols for serving media

Popular protocols for serving media Popular protocols for serving media Network transmission control RTP Realtime Transmission Protocol RTCP Realtime Transmission Control Protocol Session control Real-Time Streaming Protocol (RTSP) Session

More information

Introduction to the Application Layer. Computer Networks Term B14

Introduction to the Application Layer. Computer Networks Term B14 Introduction to the Application Layer Computer Networks Term B14 Intro to Application Layer Outline Current Application Layer Protocols Creating an Application Application Architectures Client-Server P2P

More information