Multicast ApplicationsBob Riddle – Technologist

27 September 2004

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 non-

local “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

Some useful tools …

See if you’re on a multicast-capable networkhttp://detective.internet2.edu http://dast.nlanr.net/Projects/Beacon/

If Multicast Capable: Yes – things will likely work just fine

Do a little bit of network testing

Make sure you can get from here to there without multicast

• Detective – E2E bandwidth test• Use old-fashion tools: ping, traceroute, ftp

Try a simple multicast application• 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

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)

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

Access Grid – Multicast Application

support platforms that your faculty, researchers, students were comfortable using

1. Windows XP/20002. 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

AG looks something like this

•Large-format displays•Multiple audio and video streams•Shared applications (PowerPoint)

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-to-group-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

ConferenceXP Architecture

Conference API

ConferenceXP Application

Network Transport

RTDocuments API

Rtp API

Custom UI RTDocuments UI Audio/Video UI

DirectShow

RTDocumentsCapability ViewerCapability Sender

Audio/VideoCapability ViewerCapability Sender

CustomCapability ViewerCapability Sender

IETF 1889 RFP Protocol

Multicast & Unicast UDP/IP

ConferenceXP ServicesDiagnosticsArchive/PlaybackVenue Reflector/Gateway

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:• 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• Provides the services necessary to create and manage

‘collaboration and learning venues’• Venue Service interfaces are exposed as Web Services

http://www.conferencexp.net

DVTS: What if you could use your HandiCam for Video Collaboration?

you could send & receive High Quality A/V• 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

DVTS: It looks like this:

DVTS: How can I get started?

DVTS• 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• Hardware implementation from Fujitsu Labs• Allows a “blackbox” like device to support

DV/IP• Current video conferencing tests have been

remarkable

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

… 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.  

… 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.  

… 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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