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Multicast After 9/11/2001 NANOG 23

This article discusses the use of multicast technology to improve web performance during the aftermath of 9/11 attacks. It highlights the benefits of multicast over unicast streaming and the increase in multicast traffic due to high demand for news. The stability of multicast connectivity and the need for a more robust multicast mesh are also addressed.

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Multicast After 9/11/2001 NANOG 23

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  1. Multicast After 9/11/2001NANOG 23 Marshall Eubanks tme@multicasttech.com Rich Mavrogeanes rmavro@Vbrick.com Prashant Rajvaidya prash@cs.ucsb.edu

  2. Internet News “Melt-down”9/11/2001 Web Site Performance 9:00 AM to 10:00 AM Site % Users able to access ABCNews.com 0 % CNN.com 0 % NYTimes.com 0 % USAToday.com 18 % MSNBC.com 22 % (source: Keynote’s Business Performance / Interactive Week 9/17/2001)

  3. Internet News Performance 9/11/2001 • Of course, the “melt-down” was caused by the incredible demand for news after the attacks. • Unicast Streaming web sites suffered similar problems, at least from anecdotal evidence • By contrast, multicast performed well • Large Increase in traffic • Roughly 1 Gigabit per second saved at peak • Over time, the multicast peering mesh degraded, but this was NOT due to increased traffic

  4. Eyewitness Accounts “We had a large plasma screen in the iLabs {at Networld+Interop] intended to demonstrate high rate HDTV over I2. We came in Tuesday morning and were preparing for the first day of the show when word came in about the initial plane crash into the towers. Our I2 Lead, Roy Hockett was able to switch the stream to a CNN broadcast from UMich. We began attracting exhibitors to the display even before the showfloor opened. Once the attendees were on the floor, the crowd had grown to well over a hundred. “By this point, three things had happened. The crowds around the one display had grown so large as to constitute a fire hazard, all the major news web sites had completely melted down, and CNN was being multicast from several sources. We then started loading multicast tools on every PC in the NOC, from the one driving the large video wall to people's individual laptops. By 10:30 (about half an hour after the floor opened) we had at least 3 large displays as well as a number of normal monitors turned out towards the plexiglass walls. “Soon after, we had a good number of exhibitors come and ask how to get "the CNN viewer software". Jim Martin, <jrm@nortelnetworks.com> “More than 1,000 copies of StreamPlayerII, our multicast MPEG viewer, were downloaded or handed out on disk between 9/11 and 9/12. We normally average 20 to 100 per day.” Rich Mavrogeanes <rmavro@vbrick.com>

  5. Viewership • Sudden increase in Multicast traffic of at least 1000 group members • Mostly viewing VBrick’s television broadcast • Measured Viewership > 830 • But each measured point could have many individual viewers since they multicast locally • BANDWIDTH SAVED IN EXCESS OF 1 GIGABIT / SEC. VS UNICAST Crowds viewing the 9/11 multicasts at Networld+Interop

  6. Multicast Activityat FIX-West / Mantra Purple is # of group members ^ 9/11 attack Note that extra traffic seems to be mostly US - also not all multicast traffic is visible to Mantra Attack traffic spurt was so rapid and unusual that we first thought it was a MSDP storm ! from http://www.caida.org/tools/measurement/Mantra/session-mon/session-mon.html

  7. Multicast Receivers Week of 9/10 ^ 9/11 attack Two independent monitoring efforts on two coasts saw very similar audience bursts after the attacks

  8. Multicast Receivers in September ^ 9/11 attack ^ 9/11 attack

  9. Multicast Activity on 9/11 and after • Sudden increase in Mantra traffic of > 1000 group members • Most of these seem to be television viewers • Known TV viewership > 830 • Bandwidth saved approaches or exceeds 1 Gigabit / sec. • Performance as seen from MCT was good.

  10. The Stability of Multicast • How did Multicast Connectivity behave under the attack? • We (Multicast Technologies) monitor multicast connectivity as seen by MBGP from our AS. • There were no apparent problems on 9/11 • However, there were problems starting on 9/13 when the backup power for 25 Broadway went down. • Our connectivity suffered from this.

  11. Multicast Redundancy • We (Multicast Technologies) have 3 connections into the multicast enabled Internet. • Of the 4642 MBGP prefixes advertised to us recently, 28% had only one route ! Number Routes Number Prefixes % 1 1280 28 % 2 2445 53 % 3 917 20 % The Multicast Mesh Needs to be More Robust

  12. Multicast As the Generators Ran Out… < 25 Broadway Failure ^Attack ^ Alternate Access through AUCS

  13. Conclusions • Multicast Met a Real Need after the 9/11 attacks • Over 800 video users (at least) • ~ 1 Gigabit / sec of bandwidth saved (at least) • Multicast passed its baptism under fire • Availability when other sites were spotty at best • The Multicast mesh and peering need to be made more robust.

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