Yensy James Hall, Patrick Piemonte, and Matt Weyant

这是一篇技术报告。

VoD

1. Meas

  • 3 nodes(1 MAC after cable modem, 2 PC after university switch)
  • Wireshark
  • nineteen days, 64 GB

2. Analysis

  • - found geographical location: http://api.hostip.info/get_html.php?ip=
  • - could not find the location of 31% of the IP addresses which contributed 4.58% of the data

3. App behavior

  • - based on XULRunner, a Mozilla runtime package [11]
  • - CoreAVC H.264 codec from CoreCodec [8].
  • - signaling traffic is encrypted
  • - tracker.ops.theveniceproject.com
  • - supernode snode-1.lid.ops.theveniceproject.com
  • - negotiates a port number: highly likely that a modified STUN protocol was used, similar to what [4] and [5] observed in their analyses of Skype. UDP or TCP ports?
  • - UDP probe (30 bytes) for live detecting
  • - TCP and UDP port number 4166, be used in the Now For Friends edition [12]

4. Infrastructure

  • - servers on 5 sites, UK London[10], Netherland(Admin node, SN, Web server), Belgium(content servers), Los Angeles[9], California

5. Control it within a network’s boundary

  • - port 33333

6. Ctrl and Data traffic

  • - [2] use packet sizes to seperate control and data traffic
  • Packets under 200 bytes are considered control packets - 45%, and data packets are 1000 bytes or more - 55%.

7. Traffic

  • - 700 kbps down and 100-150kbps up
  • - rate H.264 : MPEG2 : MPEG4 = 1:2.5:1.75

8. Peer

  • - Geographic Locality
    • - experiment 1 fails to get a 1min head peer in local subnet
      • - is this real? only one experiment
      • - if real, need improve here
    • - experiment 2, in all 6918 peers in 23hr, 1:1:1 from UK,US,European.
      • Is peer distribution related by time zone? it is possible
  • - 6918 peers in 23hr
    • is big enough? what is it in PPLive? "relatively low user population"
  • - "correlation between geographical distance and amount of data was -0.013"
  • - Joost server provides 71.24% of the incoming data
    • - How long joost keep download data for sharing? in memory? monitoring the memory.
  • - BT Tit-Tac is inappropriate for joost and IPTV/IPVOD.

9. RTT

  • - RTT by data size is nonsense. it can not prove RTT is/is not an affect factor for joost peer selection.
  • - measure RTT by scriptroute’s ICMP and TCP ping
  • - home pc download mainly from Joost server. LAN pc download 52% from Joost server.
  • - RTT to joost server is 90-110ms, Hop count: 15-18
    • - Have new feature to select nearest joost server
  • - roughly 80% of university client peers are within 200ms but only 10% of home client peers are within the same threshold, other > 600ms.
    • so home pc always download from joost server
  • - meas Hop count by scriptroute’s ICMP and TCP traceroute
  • - "it is unlikely that Joost selects peers based on topological locality"

10. fairness:

  • - sent/receive = 1/2
  • - because server provide at least 2/3.

11. Refer

[3] J. Liang, R. Kumar, and K. W. Ross. The KaZaA Overlay: A Measurement Study. In Computer Networks Journal (Elsevier), 2005.

  • A comprehensive measurement study of KaZaA’s overlay structure is undertaken in [3]
  • looked in depth at the KaZaA and FastTrack overlay networks with both active probing and passive trace analysis.
  • The identification of peer-to-peer traffic
  • Techniques to analyze and characterize peer-topeer traffic and file-sharing workloads
  • The development of crawling systems for Gnutella, Napster, and KaZaA
  • A study of scalability issues in the Gnutella network
  • A study of the problem of search and replication strategies in unstructured peer-to-peer networks
  • A study about the advantages of designing unstructured peer-to-peer systems based on super peers

[2] K. Gummadi, R. Dunn, S. Saroiu, S. Gribble, H. Levy, and J. Zahorjan. Measurement, Modeling, and Analysis of a Peer-to-Peer File-Sharing Workload. In Proceedings of SOSP, 2003.

  • [2] discovered that KaZaA does not take advantage of locality to manage its overlay network and proposed performance improvements if KaZaA were localityaware.

[4] S. Guha, N. Daswani, and R. Jain. An Experimental Study of the Skype Peer-to-Peer VoIP System. In Proceedings of IPTPS, February 2006.

[5] S. Baset and H. Schulzrinne. An Analysis of the Skype Peer-to-Peer Internet Telephony Protocol, http://arxiv.org/abs/cs/0412017v1, 2004.

  • [4] and [5] examined Skype’s application behavior and supernode infrastructure.

[6] B. Cheng, X. Liu, Z. Zhang, and H. Jin. A Measurement Study of a Peer-to-Peer Video-on-Demand System. In Proceedings of IPTPS, February 2007.

  • [6] studied an on-demand P2P video system called GridCast. GridCast was deployed in China in 2006 to over twenty thousand users, hundreds of which were supported concurrently.

Misc

  • [7] V. Paxson. Strategies for Sound Internet Measurement. In Proceedings of ACM SIGCOMM Internet Measurement Conference’04, Taormina, Italy, November 2004.
  • [1] S. Ali, A. Mathur, and H. Zhang. Measurement of Commercial Peer-To-Peer Live Video Streaming. In Workshop in Recent Advances in Peer-to-Peer Streaming, August 2006.
  • http://developer.mozilla.org/en/docs/XULRunner
  • http://www.joostteam.com