AREN

1
Experiences with Unicast/Multicast Tutorials and
International Classes at the University of
Alabama in Huntsville Robert L. Middleton,
P.E. Senior Research Engineer University of
Alabama in Huntsville Richard T. Bagwell Senior
Network Engineer Alabama Research and Education
Network
2
Background

• The Huntsville based National Center for
  Childrens Advocacy wanted an Internet based
  replacement for their Satellite based Tutorials
• UAH Internet based streaming video and
  synchronized PowerPoint slide approach viewed as
  probable replacement.

3
Requirements

• High quality Video and Audio
• Multiple formats of Video
• Mixture of pre-recorded and live video to enable
  remote site Q/A session
• No new equipment at remote sites
• Pre-scheduled start and stop times
• Delivery to a large number of paying sites
• Security

4
Approach

• Simultaneous Multicast and Unicast from our
  server over both Internet 2 and Internet
• Microsofts Producer enabled recording and
  placing video/text material on a timeline.
• Internet Explorer and Windowsmedia Player free
  downloads for remote sites
• Windowsmedia Server capable of all desired
  features

5
Network configuration

• Both UAH and AREN Networks needed some upgrading
  to accommodate Multicast
• Current streaming video server with MS
  Windowsmedia Sever software OK
• Extensive testing of Multicast/Unicast to remote
  sites performed

6
Tutorial Delivery

• Lobby site had countdown clock and test video for
  last pre-check
• Remote sites joined either a multicast or unicast
  Lobby site 15 Min. prior to start.
• Start to finish of tutorial (2.5 Hrs), including
  Live q/A session, remote sites were on
  autopilot and required no attention, as on TV.

7
Demonstration Tutorials

• National Childrens Advocacy Center Tutorial 2
  (October 24, 2002).
• Joint Class with French Engineering School ESTACA
  (February 2003)

8
A Few Technical Issues with Producer Multicast
Deployment

• Multicast Group address space
• Software Version/Compatibility Issues
• Campus Networking Challenges
• Inter-domain Multicast Magic

9
Multicast Address Space

• Microsoft Producer uses randomly assigned
  Multicast group addresses
• During initial testing, Microsoft defaults were
  used
• We began to worry that Producer was not
  reserving these addresses with any central
  authority
• The addresses could be overlapping with other
  applications (such as the legacy Mbone tools and
  Cisco IPTV) that can use SDR to reserve group
  addresses
• Although this overlap may not cause application
  problems, it could result in unwanted traffic.

10
GLOP Addressing

• RFC3180 GLOP Addressing in 233/8
• Current best practice is to use multicast address
  space that is derived from your AS number
• Provides a single /24 of multicast address space
  per AS
• UAH manages their GLOP addressing using their
  existing Unicast address inventory tool
• Dynamic assignments can be made via an extension
  to DHCP called MADCAP RFC2730 in the future

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UAHs GLOP Space
UAH Autonomous System Number 10364
10364d 00101000 01111100b 00101000b
40d 01111100b 124d AS 10364 ?
233.40.124.0/24
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Troubleshooting IP Multicast Functionality of
Microsoft Producer

• Problems Encountered
• Client Software Version Issues
• Campus Multicast Complications
• Wide Area Inter-domain Multicast Problems

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Client Software Issues

• Producer relies on Internet Explorer (IE) and
  Windows Media
• Only foolproof configuration Clients running
  XPpro operating system with updated Windows Media
  and IE
• Good but spotty results with Win2K and Win98SE
  machines with updated Windows Media and IE
• Use of XP was encouraged in testing since its
  used removed at least one possible problem from
  our troubleshooting list

14
Campus Multicast Complications

• UAH campus infrastructure upgrade (ATM to GigE)
  coincided with our multicast testing
• Initially had to disable mls for multicast on
  campus 6509 Layer3 switch/router.
• Testers outside Alabama often were unaware if IP
  Multicast was enabled on their local networks
• Initial troubleshooting tool was Cisco IPTV
• attempting to view NASA clips from OR
• Best tool found Internet2 Detective

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Internet2 Detective

• http//detective.internet2.net/
• Test connection to Abilene
• Test if subnet is Multicast Capable
• Dont need to call campus IT folks

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Wide Area Inter-domain MulticastTroubleshooting

• IP Multicast on Abilene currently relies on a
  combination of three protocols
• PIM-SM, MBGP, MSDP
• Problems were encountered when BGP used
  non-multicast capable links for traffic between
  UAH and AREN NOC
• Solved by judicious use of BGP filtering
• The BGP issue was a direct result of topology of
  network in Alabama

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Alabama Logical Network Topology(GCG and AREN)
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Inter-domain Multicast Troubleshooting Tools

• The most useful tool for troubleshooting Router
  show commands
• We had direct access to AREN, UAH, and GCG
  routers.
• Abilene routers accessed trough the Abilene Core
  Node Router Proxy
• http//www.abilene.iu.edu/tools.html

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Most Common TroubleshootingCommands for Cisco
Routers
Router show ip mroute
provides a look at the Multicast routing
table Router show ip msdp peer
shows peer state, traffic, and filters Router
show ip msdp sa-cache shows the
service advertisement cache and allows
you to confirm msdp is correctly
advertising sources. Router show ip bgp
neighbor Confirms multicast routes are
active
(and tons of other
stuff) Router debug ip pim 233.40.124.1
Confirm PIM domain config is joining correctly
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Summary and Conclusions

• High quality Education and Training can be
  delivered to Internet 2 (and extensions)
  connected Schools in both live and asynchronous
  formats via Unicast/Multicast
• Campus LAN Traffic inhibits Multicast video
• Time zone differences encourage asynchronous
  Unicast delivery

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Summary Conclusions 2

• Many Universities who tested our NCAC Tutorials,
  could receive the Multicast material, but most
  elected the Unicast option.
• Homeland Defense communication needs may
  advance Multicast capabilities.
• For more info on UAH efforts, our Case Study is
  available from Microsofts website

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Closing Credits

• UAH Computer Network Services
• AREN
• NCAC
• Microsoft Producer and Windowsmedia Teams
• Dr. Robert Frederick (IPT Classes)
• Dr. Bill Kearns- Dir. USF-DMHC (pilot testing)
• Mr. James A Williamson Jr.- UAH Graduate Asst.