Kun Wei weikun@caltech.edu
California Institute of Technology
Copyright © 2001-2003 by California Institute of Technology
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1. Introduction
1.1 About this document
1.2 What is VRVS?
1.3 VRVS-AG Bridge
1.4 Acknowledgments
2. Connection Setup Scenario 1 (with MBone Client)
2.1 What are the MBone tools?
2.2 Register within VRVS and download VRVS MBone package
2.3 Select Access Grid Virtual Venues
2.4 Setup MBone audio tool parameters (Optional)
2.5 Connect and Interact with Access Grid
2.6 Select View Mode
2.7 Useful Mbone Hints
3. Connection Setup Scenario 2 (with H.323 Client)
3.1 What is H.323?
3.2 Register with VRVS and Select Access Grid Virtual Venues
3.3 Connect and Interact with Access Grid
3.4 Select View Mode
3.5 Useful H.323 Hints
| Revision 1.0.0 | January 10, 2002 | |
| Draft based on VRVS 2.5 | ||
| Revision 1.0.2 | March 25, 2002 | |
|
Initial publication on AGDP. | ||
| Revision 2.0.0 | Novembenr 14, 2002 | |
| Darft based on VRVS 3.0. Improvements on Web interface connection, MBone video modes, H.323 audio bridge and other VRVS 3.0 related new features. | ||
This HOWTO provides information for users anywhere in the world to access Access Grid conveniently and easily with normal unicast Internet connection through VRVS-AG Bridge. The HOWTO applies to users who want to attend Access Grid ongoing sessions but cannot connect to an Access Grid Node, which needs high bandwidth (20Mbps minimal) and multicast network. The following table compares the basic connection requirements and expections.
| Access Grid | VRVS | Access Grid via VRVS | |
| Multicast Enabled Network | X | X | X |
| Unicast Network | X | X | |
| On-Site AG Node | X | X | X |
| Without AG Node | X | X | |
| High Quality Video | X | X | X |
| High Quality Audio | X | X | X |
| H.323 Protocol Support | X | X | |
| High (> 20Mbps) BandwidthNetwork | X | X | X |
| Normal (10Mbps) / Low (<1Mbps) Bandwidth Network | X | X |
The Virtual Room Videoconferencing System (http://www.vrvs.org) provides a low cost, bandwidth-efficient, extensible means of videoconferencing and remote collaboration over networks within the High Energy and Nuclear Physics communities. Recently VRVS also extends the service to othervarious academic/research areas.
Since it went into production service in early 1997, deployment of the Web-based system has expanded to include 7800 registered hosts running the VRVS software in more than 60 countries. A set of 50 "reflectors" interconnected using unicast tunnels and multicast manage the traffic flow at HENP labs and universities in the US, Europe, Asia, and South America. VRVS provides the versatile collaboration tools: MBone (VIC/RAT), H.323 (Polycom, NetMeeting, etc.), QuickTime, SIP, JMF, MPEG2, Desktop/Application sharing and Chat on various platforms.
Recent and ongoing developments include support for scalable peer-to-peer infrastructure, MPEG4 videoconferencing, shared collaborative environments, QoS over networks, etc. The goal is to support a set of new and essential requirements for rapid data exchange, and a high level of interactivity in large-scale scientific collaborations.
VRVS and the Access Grid group at MCS/Argonne National Laboratory have cooperated to build the first bridge between the Access Grid multicast cloud and outside unicast streams. MCS/Argonne National Laboratory generously provided the gateway machine on which the VRVS reflector performs the bridging and switching functionality. Recently another VRVS-AG Bridge was deployed at Internet2. More VRVS-AG Bridges will be deployed for dedicated Access Grid nodes per request.
Since the launch of VRVS-AG Bridge, many world-wide users have used it to connect to Access Grid conferences such as NSF Workshop, SC01 and GGF.
This document is derived from the documentation available on the VRVS website, and the VRVS/Access Grid Integration release notes. Many thanks to Professor Harvey Newman, Dr. Rick Wilkinson, Sarah Emery Bunn and the VRVS Team for reviewing this document and for their valuable suggestions.
Users who want to connect to Access Grid through VRVS with Mbone tools (which are used by VRVS and Access Grid for video/audio transmission) need to take the following steps:
The MBone video tool used by VRVS and the Access Grid is VIC. VIC is a tool that allows groups of users to transmit and receive video to/from each other over IP multicast. VRVS and the Access Grid use RAT for sending/receiving audio. RAT (Robust Audio Tool) is a multicast audio tool for conferencing and audio streaming over an IP network.
If you are not registered with VRVS yet, go to the VRVS website (http://www.vrvs.org), register your profile and install the software. The whole process will take less than 2 minutes. To fully compatible with Access Grid MBone tools, you need to install a VRVS package that includes RAT (MBone audio tool) version 4. You can get more information from http://www.vrvs.org/Documentation/.
Figure 1. Register with VRVS and Install MBone package
After login successfully, in the top panel select AccessGrid from Community, select the AG Virtual Venue and click ENTER icon. You can also select from the List of ongoing Meetings* by clicking the Access Grid icon or name.
* In other communities, only the real-time ongoing meetings are listed. Only in the Access Grid community, all the Access Grid Virtual Venues are listed here. To know the real-time ongoing meeting, you need to check AG Schedule.
Figure 2. Select and enter an Access Grid Virtual Venue.
For more information on Access Grid Virtual Venues, please refer to AGDP's other documentation (http://www.accessgrid.org/agdp/ ).
Now you are in the selected Access Grid Virtual Venue. Click the "CONNECT VIC & RAT4" button*, VRVS AG Bridge will load the VIC and RAT automatically. In case you only want to start MBone audio tool, check "audio only" before click the "CONNECT VIC & RAT4" button. Remember you should use RAT version 4.
* The label of this button reflects your current connection preference. You can select what you prefer to connect by clicking H.323 Client or Other Clients tab on connection applet.
Figure 3. Click CONNECT button to to launch MBone tools - VIC and RAT version 4
The following steps are optional. You can use the VRVS default audio setup without any problem. Only when you want to setup the MBone audio tool parameters to comply with AG audio setting, take the following steps. Click on "Options", select "Audio" from "Category" menu and set "Sample Rate:" to "16-KHz".
Figure 4. RAT Audio Sample Rate Setting
Select "Codecs" from the "Category" menu, and set "Codec" to "L16-16K-Mono".
Figure 5. RAT Codec Setting
Now you can fully interact with other nodes whether they are connected as normal Access Grid Nodes or via VRVS. Depending on the network bandwidth and video/audio hardware configuration, you may notice the qualitative and quatitative differences. Access Grid Nodes are built on high bandwidth mulitcast network with high quality (also expensive:) video/audio equipment. Without high bandwidth multicast network enabled and Access Grid Node access, you can connnect the Access Grid events via VRVS. The video/audio quality will depend on your local hardware configuration.
For more information on how to use MBone tools, please refer to AGDP (http://www.accessgrid.org/agdp/) or VRVS Documentation ( http://www.vrvs.org/Documentation/).
Figure 6. Snapshot of Access Grid Virtual Venue connecting with MBone
Once you are connected, you will first receive ALL the video and audio streams. To avoid overdriving your local machine, VIC will receive all the video streams for a few seconds, and switch to Selected Streams video mode. Only randomly selected 8 video streams will keep alive then. To change the default video mode, you can click the "Video Modes" tab on the connection applet.
Figure 7. Change Video Modes
With Mbone, you can select from three video modes:
Figure 8. Adjust VIC Transmission Parameters
"The H.323 standard provides a foundation for audio, video, and data communications across IP-based networks, including the Internet. H.323 is an umbrella recommendation from the International Telecommunications Union (ITU) that sets standards for multimedia communications over Local Area Networks (LANs) that do not provide a guaranteed Quality of Service (QoS). These networks dominate today’s corporate desktops and include packet-switched TCP/IP and IPX over Ethernet, Fast Ethernet and Token Ring network technologies. Therefore, the H.323 standards are important building blocks for a broad new range of collaborative, LAN-based applications for multimedia communications. It includes parts of H.225.0 - RAS, Q.931, H.245 RTP/RTCP and audio/video codecs, such as the audio codecs (G.711, G.723.1, G.728, etc.) and video codecs (H.261, H.263) that compress and decompress media streams. " -- http://www.protocols.com/pbook/h323.htm.
There are many H.323 protocol implementations around, such as Microsoft NetMeeting (http://www.microsoft.com/windows/netmeeting/), Polycom ViewStation / ViaVideo (http://www.polycom.com/), OpenH323 (http://www.openh323.org/ ), etc. The H.323 product will have better lip-sync, smooth switching and other useful features for IP-based videoconferencing.
To successfullyuse H.323 client to join Access Grid event, there are certainlimitations as description below.H.323 clientsalso need to make well maintainence on devices and have good strategy to participate the Access Grid event. For example, mute your microphone when you are not speaking, avoid local loopback echo, make a test before formal conference, etc.
Figure 9. H.323 Protocol
Users who want to connect to Access Grid through VRVS with H.323 clients need to take the following steps:
If you are not registered with VRVS yet, go to the VRVS website (http://www.vrvs.org) and register your profile.
Figure 10. Register with VRVS
After login successfully, in the top panel select AccessGrid from Community, select the AG Virtual Venue and click ENTER icon. You can also select from the List of ongoing Meetings* by clicking the Access Grid icon or name.
* In other communities, only the real-time ongoing meetings are listed. Only in the Access Grid community, all the Access Grid Virtual Venues are listed here. To know the real-time ongoing meeting, you need to check AG Schedule.
Figure 11. Select and enter an Access Grid Virtual Venue.
For more information on Access Grid Virtual Venues, please refer to AGDP's other documentation (http://www.accessgrid.org/agdp/ ).
Now you are in the selected AG Virutal Venue. Click "H.323" Client. Check "Use H.323" option. If the H.323 is attached to your own machine (e.g. Polycom ViaVideo, NetMetting), enter your own machine's IP address. You can get your current IP address by clicking "this machine" button. It is helpful in case you are not sure about your current IP address. Especially your machine is setup with DHCP and may change IP address dynamically.
Select bandwidth and frame rate based on your network connection. Please refer to VRVS FAQ on how to select H.323 bandwidth and frame rate.
If your H.323 is managed by gatekeeper, ask your H.323 gatekeeper administrator about gatekeeper address, alias and other information. Check "Gatekeeper" option, and provide gatekeeper's IP address. In this case, you can put alias in HostIP/Alias entry.
Figure 12. Set H.323 connection parameters
Now you are ready to join an Access Grid session with your H.323 client. Click "Main" tab on the connection applet. Click "CONNECT H.323" to connect the H.323 device. In case you only want to connect audio, check "audio only" before connecting. You will receive a call from VRVS H.323 Agent. Accept it.
Figure 13. Click CONNECT button to connect the H.323 device
Once you are connected you are receiving only one video stream by default. To change video mode, click "Video Modes" tab on the connection applet.
Figure 14. Change Video Modes
You can select from four different modes: