Download 11_Multicast_Applications

Multicast Applications
Bob Riddle – Technologist
27 September 2004
Internet2 Commons H.323 Site Coordinator Training
What’s different about Multicast?
What if your home telephone were multicast
instead of unicast?
• Anyone old enough to remember when your home phone was a
“party line”?
• Anyone old enough to remember TV before cable TV & satellite
TV?
– “Broadcast” to local area
– cable/satellite TV kind of like “multicast”, lets you tune to a nonlocal “broadcast” channel
Multicast – learn the language, acronyms, the
protocols
• IGMP (v1, v2, v3) PIM, MSDP, RP, BSR
• You can either become a network engineer or find some useful
tools
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Some useful tools …
See if you’re on a multicast-capable network
http://detective.internet2.edu
http://dast.nlanr.net/Projects/Beacon/
If Multicast Capable: Yes – things will
likely work just fine
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Do a little bit of network testing
Make sure you can get from here to
there without multicast
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Detective – E2E bandwidth test
Use old-fashion tools: ping, traceroute, ftp
Try a simple multicast application
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Vic, rat, sdr - http://www.openmash.org/
Listen to some multicast stream http://people.internet2.edu/~bdr/dvguide.html
If all this works for you – you’re ready
to run ConfXP, the AG, … whatever
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Is multicast a “good” thing?
Think about “bigvideo” streams:
• DV/IP: 30 mbps stream, for “broadcast” events the
unicast client/server model won’t scale on your
network
• HDTV Compressed with MPEG2 is about 20 mbps
It’s an alternative to the MCU
• Moves “session” management to the network layer
• You don’t need the investment in an MCU
• You (most likely) will need a “bridge”
(http://if.anu.edu.au/SW/rcbridge.html)
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Access Grid – Multicast Application
provide a sense of presence, of “being
there” where distributed people could
interact as if they were sharing the same
“room”.
using readily available collaboration
technology that was affordable
integrate with existing security services
and available network capabilities
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Access Grid – Multicast Application

support platforms that your faculty,
researchers, students were comfortable
using
1. Windows XP/2000
2. Linux variants (RedHat, Slackware, Fedora, Debian,
…)
3. Mac OS X (in the future)

support existing environments to allow
people to collaborate where they are
1. Room – Shared Display, Multiple Video Streams, Single
Audio Stream
2. Desktop – Desktop Monitor, Multiple Video Streams, Single
Audio Stream
3. Laptop – Laptop Display, Single Video Stream, Single
Audio Stream
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AG looks something like this
•Large-format displays
•Multiple audio and video streams
•Shared applications (PowerPoint)
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http://www.accessgrid.org/community/nodes/nodes.html (over 200 nodes)
ConferenceXP – Microsoft Learning
Sciences & Technology Group
• “AG-like” Goals:
•
Single-machine architecture capable of scaling to handle large, group-togroup-to-group conference scenarios
•
Simple software installation and hardware configuration, No conference
session operator is required
•
Cameras, microphones and other peripherals are configured for a ‘best fit’
default configuration
•
Rich, immersive collaboration environments require that audio and video
streams are delivered with high quality and low latency
•
Collaboration venues provide the virtual equivalent of meeting and
gathering places
•
A simple, configurable archival system enables individual participants to
record and playback conferences
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ConferenceXP Architecture
ConferenceXP Application
Custom UI
RTDocuments UI
Audio/Video UI
Conference API
Custom
Capability Viewer
Capability Sender
RTDocuments
Capability Viewer
Capability Sender
RTDocuments API
Audio/Video
Capability Viewer
Capability Sender
DirectShow
Network Transport
Rtp API
IETF 1889 RFP Protocol
Multicast & Unicast UDP/IP
ConferenceXP Services
Venue
Reflector/Gateway
Archive/Playback
Diagnostics
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ConferenceXP Client
 Provides a high bandwidth, low latency audio and visual
capability
 Utilizes Windows Media High Quality Audio & Video
Codec's, DirectShow, and a custom low latency
networking stack (RTP).
 The ConferenceXP UI is integrated The Edge, an MSR
Learning Sciences and Technology project focused on
building a UI for learning web services
 The conferencing architecture supports:
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Full screen video at 30 fps, with 250 ms latency
FireWire cameras to enable high quality, efficient video capture
Five way conferencing < 2 Mb/s
Venue Service
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Provides the services necessary to create and manage
‘collaboration and learning venues’
Venue Service interfaces are exposed as Web Services
http://www.conferencexp.net
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DVTS: What if you could use your
HandiCam for Video Collaboration?
you could send & receive High Quality A/V
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It doesn’t require funny, expensive machines
It doesn’t require involve IP issues (royalties)
It doesn’t require funny, expensive cameras
It does require a network capable of 30 mpbs
all you need is a capable Network and …
• a DV capable camera (HandiCam, DVCAM, DVCPro) with
IEEE1394 (firewire) capability
• DV receiver (DV Player, TV) that is firewire capable
• Or an analog/digital converter(s) if using a non-firewire
capable camera/receiver
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DVTS: It looks like this:
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DVTS: How can I get started?
DVTS
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Software encoding/decoding using the PC
processor, NIC, etc.
Runs on number of platform, though
Windows XP has the best GUI and uses PC
monitor for display
Requires a firewire card if you are a
“sender” (and receiver for non-WinXP)
Provided by DVTS Consortium & WIDE
project http://www.sfc.wide.ad.jp/DVTS
CometDVIP
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Hardware implementation from Fujitsu Labs
Allows a “blackbox” like device to support
DV/IP
Current video conferencing tests have been
remarkable
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where does DV/IP live in the video
“neighborhood”?
H.323 – How is it different?
• Multicast use removes need for MCU
• Higher quality, lower latency a/v streams
Access Grid – can I use it with my AG?
• Current integration work underway (APAN/ANU)
MPEG2 – why not just use mpeg2?
• No “IP” encumbrance, Higher quality, lower latency a/v
streams
HDTV - why not just use HDTV?
• Lower latency than compressed (20mbps) HDTV stream
• Lower bandwidth than uncompressed HDTV stream
“Sweet spot” – if you have the bandwidth
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… in the wings … Pocket Video …
test, experiment, develop and integrate
various interactive video technology on
handheld devices over the Internet.
allow those who possess such devices to
participate in existing collaborative sessions,
such as AG, SIP, and VRVS conferencing.
exploit Handheld device capability in ways
that extend the research & teaching missions
of universities while taking advantage of
readily available and affordable technology.
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… in the wings … Pocket Video …
test, experiment, develop and integrate
various interactive video technology on
handheld devices over the Internet.
allow those who possess such devices to
participate in existing collaborative sessions,
such as AG, SIP, and VRVS conferencing.
exploit Handheld device capability in ways
that extend the research & teaching missions
of universities while taking advantage of
readily available and affordable technology.
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… in the wings … Pocket Video …
The following projects are currently proposed:
explore use of AG tools on iPaq using
Familiar Linux
• http://internet2.motlabs.com/ipaq/
• http://familiar.handhelds.org/
explore VRVS 3.0 on iPaq under WinCE
• http://www.vrvs.org/Documentation/pocketVRVSguide.html
explore Microsoft Portrait work done by
Microsoft Research
• http://research.microsoft.com/~jiangli/portrait/
explore Palm Pilot resources available to
support collaborative, interactive applications
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