Draft Minutes of the meeting on High Quality Video Conferencing

Transcription

1 Draft Minutes of the meeting on High Quality Video Conferencing 26 June 2001 University of Edinburgh, United Kingdom Valentino Cavalli, Issue 1 Attendees Name Organisation Country Rodrigo Castro RedIRIS Spain Valentino Cavalli (Secr) TERENA - Jose Maria Fontanillo RedIRIS Spain Brian Gilmore University of United Kingdom Edinburgh George Howat University of United Kingdom Edinburgh Steven Jack University of United Kingdom Glasgow Bart Kerver SURFnet The Netherlands Victor Reijs SURFnet & HEAnet The Netherlands & Ireland Harri Salminen (via CSC/FUNET Finland conference) Benoit Schmid University of Geneva Switzerland Jim Sheach University of United Kingdom Edinburgh Egon Verharen (Chair) SURFnet The Netherlands Apologies Name Organisation Country Bob Riddle Internet2 USA 1. Welcome and Introduction Egon Verharen, SURFnet

2 Egon welcomed the participants and briefed them about the purpose of the meeting. The primary objective was to exchange information about experiences with high quality tools and services, as well as to identify problems and common solutions in deploying high quality services. Possible outcomes of the meeting could be the creation of a group and the definition of some joint activity. Egon remarked that TERENA is available to support international collaboration on digital, even though it would not be carried out like it was in the task force TF-STREAM, but rather in the form of focused projects with clear commitment by the participating organizations. 2. Presentation on the SMVC experience George Howat, University of Edinburgh, George presented the Scottish Metropolitan Video Conferencing Network, SMVCN. Since early 90s in Scotland they started deploying by initially providing H.320 service at 2Mbps. George said that unfortunately the experience was disastrous because the quality for the end user was very low, and at that time there was no possibility to control it. On the other hand users had very high expectations and requirements, and were discouraged from using the service. The main quality issues were audio, echo cancellation and stability of the environment. The SMVCN was established in 1996 with the main goal of ensuring service stability, user-friendly environment and better quality. George remarked that one advantage for the customers is that the service provided in Scotland is free at point of delivery. To maintain continue level of Quality Assurance, tests are repeated every three months and/or whenever complains are received from the customers. The SMVCN is a Studio-based network which uses CellStack (CSV) M-JPEG/ATM codecs and gateways to H.320, H.323, H.261 (Mbone, pervasive in higher education). The gateways are provided by putting the codecs back-to-back. The SMVCN provides Multipoint based on duplicate stream pointto-multipoint signal. In 1999 one third of all conferences were multipoint, the ratio is even higher now. Data from show that 50% of the users are connected via gateways. The Scottish service has many QoS features, including bandwidth reserved on ATM network, booking system control request, VBR signaling, PNNI. However, low quality is also appropriate in some cases, George mentioned a study paper investigating the quality requirements of outreach, international, informal meetings, showing that QoS is not always needed. Another result of the study is that desktop needs integration with studio-based.

3 The Scottish experience is very successful, however it needs to be changed because the MAN is going to be re-procured before the end of July 2002 and there is no ATM support in SuperJanet4. In the future of the Scottish Higher Education Video Conferencing Service they would like to set up a two-front process with H.323 on the one side and high quality for the more demanding community on the other side, but over IP networks. There are good and bad things involved in the change. The advantages are that this would allow the service to make use of standard-based equipment and to integrate it with other systems. The disadvantages will be related to proprietary CSV, limited interoperability, very poor scaling on 155 Mbps networks, plus other problems with latency and echo cancellation. Finally, George remarked that in migrating from ATM to IP one needs to take care of the QoS sensitivity of the applications. They tested Tandberg H.323, and involved in supplier (Cisco and Juniper) tests of ATM over IP, as well as studying PC based gateways for relaying ATM AAL5 over IP. Similar studies by Nobuaki Takahashi show that the packet-loss tolerance may vary from 1/50 for CellStack to 1/500 for MPEG-2 Distance and to 1/100,000 for ATM-IEEE1394 link unit. Egon mentioned a document about Digital Video over transatlantic links between the MIT and Japan. Information about the project is available at the following URLs: projectpage : relevant details : report : Reports/DV/ Egon said he would contact Internet2 and find out what results they got exactly in terms of packet-loss tolerance. Egon remarked that problems with lip-synchronization might still be an issue today, for instance, he said, in their room at SURFnet they project on the screen whereas audio comes from different equipment. Audio latency is another issue, and one has to consider how many millisecond is the limit depending on different kinds of interaction, like presentation, discussion, and so on. ACTION: Egon to provide information about experiments on Digital Video over transatlantic links.

4 ACTION: George to release the SMVCN draft document - DONE, online draft Study into Video Services in Scottish Higher Education. 3. HEAnet testing of High Quality Victor Reijs, SURFnet & HEAnet, Victor presented testing activities and plans at HEAnet. He said that H.323 is easy and they are certainly going to provide it but will also investigate in High Quality Video Conferencing. In the area, they had carried out experiments with Litton Codecs on intercontinental link between the National Medical Library in Washington and TCD Dublin at 1.5 to 15 Mbps, low-latency MPEG-2 codecs. Different, very expensive, boxes were needed for echo cancellation. Lot of things went wrong with the experiments: one-way packet loss was greater than 1% and really did not work, there were delay and delay variance problems and other related to connectors, high loads on the transatlantic link, mismatching ATM PVC configuration and so on. 'Remember that it is important to have on both sides the same standard (like PAL or NTSC). If they are different, communications is not possible. This can make communications between countries that have different encodings different (e.g. if with USA, one side will have to change, so that both side have the same encoding).' One main issue was that the boxes do not say anything about the network and good tools are needed for monitoring it and find out what is wrong. Even operational network managers were not able to detect packet drop. Another result is that H.323 degrades nicely, whereas these tools either work or not and therefore need some form of guaranteed QoS to be provided either by overprovisioning bandwidth or by implementing a premium IP service. Finally, Victor pointed out the importance of having the same standard (like PAL or NTSC) on both sides. If they are different, communication is not possible. This can make communications between countries that have different encodings different (e.g. if with USA, one side will have to change, so that both sides have the same encoding). Next step in Victor`s research is predicting/monitoring QoS. A few recommendations are that manufacturers should test the requirements of their application over (impaired) IP networks and define the perceived quality of applications. Good test/debugging tools should be provided for specific applications. Some research is carried out by the task force TF-NGN in defining the QoS metrics and test requirements and by the Internet2 QoS group, looking into applications and what they do on QoS networks.

5 4. Round of table presentations from other participants The Netherlands - Bart Kerver, SURFnet SURFnet are providing services and high quality streaming. Bart said he currently works on lower quality and MPEG-4 streaming. He mentioned that there are a few initiatives to evolve encoding formats into different standards. Bart is particularly interested in Virtual Reality. He is working with SARA in Amsterdam on a project for the CAVE, (called Remote Cave) a large project on high-quality virtual reality environment. The Virtual CAVE project has raised a lot of interest, and SURFnet have received two proposals for testing streaming software on that environment. Another interesting proposal was about testing high quality MPEG-1 between the Netherlands and the United States in the medical application area. The streaming activity regards content created by students. Bart said SURFnet plan to broadcast the content to their network. They are interested in getting experience with M- JPEG. Egon remarked that in the Netherlands there is higher demand for streaming than for. SURFnet has organized a number of events to introduce services to the research and education community. The last one in Amsterdam was very well attended but there was very poor follow up. Egon argued that one reason for the low response was related to the size of the country. On the other hand he remarked that there is lot of interest at the International level. Both work is done in the Internet2 Commons initiative and with several TERENA members on a European dialing plan and gatekeeper organisation. Egon mentioned that the Research Channel would like to broadcast an international 1-hour high-quality streaming to IP networks in some countries in Europe. Interest has been expressed by the Netherlands and the United Kingdom. SURFnet runs several services in collaboration with content providers in the Netherlands like KRO, NAA (Dutch Audiovisual Archive) and NOB. George lamented that in Scotland they do not have as good liaisons with content providers as SURFnet. Switzerland - Benoit Schmid, University of Geneva Benoit said they provide by using products based on ATM point-to-point connection and are now facing the problem of migrating to IP networks. Therefore they need to find alternative solutions in order to be able to provide good quality services to end-users. To this purpose they have done

6 several tests with various equipment. They had two Litton CamVision-2 on loan from TERENA but the tests resulted very badly, it also appeared that the boxes are too big and noisy. Tests with Vbrick MPEG-1 and MPEG-2 were not satisfactory too. Geneva were planning to try Minerva boxes like those used between Caltech and CERN, Benoit said that he got in contact with Minerva but did not received an answerd, he things that Minerva want to focus more on Cable-TV than on IP products. Other experiment plans include trying the Optivision MPEG2 boxes: Benoit was able to get in touch with Optivision, but at the time of the meeting was still waiting for a feedback from them. Additionally, he mentioned products for and surveillance provided by the Swiss company VisioWave. Finally Benoit said he was looking for feedback also on H.323 products. He found the Picturetel 850 rather disappointing, even though it looked to work fine on the LAN. George said he had heard very positive reports about Optivision on Ethernet. Egon remarked that the University of Hawaii has deployed Optivision boxes, and he was willing to ask them if there is some report that can be made publicly available. ACTION: Egon to contact David Lassner from the University of Hawaii about available public reports on Optivision. - DONE Spain - Rodrigo Castro, RedIRIS Rodrigo talked about a project recently started by RedIRIS and involving several universities in Spain to create a streaming service network as a facility to share educational content. The service would be implemented with Kasenna servers that were chosen because they provide good media management, (Oracle) database integration and assets customization. The server is provided on Linux, Solaris and Lynx; supported encoding formats include Real, Windows Media, QuickTime and MPEG-1. Moreover, RedIRIS are working on a document to standardize in their community, aiming at promoting the creation of a network of rooms on a guaranteed-service network infrastructure. The document focuses only on recommendations, RedIRIS does not plan to provide any central management as well as equipment in the project. Feedback from the participants pointed out the benefits of the centralized service provided in Scotland and the risks involved in leaving the management of the network service to the individual institutes. In addition George said that Ukerna and the Scottish network already published a recommendation paper and RedIRIS, but also other interested parties, could access that. He would provide further information on request.

7 Rodrigo said that one VRVS reflector is operational in Madrid since spring 2001 and that RedIRIS established some collaboration with CERN in improving the VRVS service. They found that integration between VRVS and H.323/Mbone was good and would continue to work on this. In addition, RedIRIS was planning to start a project on evaluation of solutions for Voice over IP. Finland - Harri Salminen, FUNET Harri said they have a lot of bandwidth available for the users in Finland and is provided as an operational service, however there is no central management/funding as in Scotland. The service is managed by a university consortium, but users are very distributed and they need to interoperate. FUNET has lot experience with H.323 but are now looking for other solutions available for IP networks. Harri mentioned tests carried out with the Litton boxes, which worked mostly fine, with the exceptions of some connection problems and some packet-loss in the International link. At FUNET they are now looking at Minerva VNP, Video Network Platform, boxes, VRVS, H.323. They are currently running some highquality streaming experiments with several equipment. Optibase MovieMaker was used only for one-way streaming. Harri said his group is interested in QoS reservation, but they need to define which kinds of classes are actually required. An open issue is also MPEG-2 interoperability. He recalled that the MPEG-2 forum, even though it seems to involve all manufacturers, still did not publish any result. United Kingdom - Steven Jack, University of Glasgow and Jim Sheach, University of Edinburgh Steven expressed the interest of the Glasgow University in both streaming and. Being a member of the SMVCN they share the common infrastructure and in addition provide remote campus services. Same as Edinburgh they are looking at migrating from ATM to IP networks. On the streaming side, Steven said they are running services based on Windows Media at the moment, but are looking at other solutions. Finally they are also interested in IP TV and Voice Over IP. Jim said he had been involved in resourcing conferences for Medical Radiology departments in Edinburgh, Dundee and Glasgow. This community require very high quality images and described the current SMVCN Cellstack system as "OK, but would like something better". He also described his work as part of the Video

8 Technology Advisory Service, funded by UKERNA which carries out product evaluations on H.320 and H.323 codecs, some work had also been done on MPEG systems. The reports are posted on the VTAS web site - Valentino Cavalli, TERENA Valentino briefly announced that the TF-STREAM task force was going to be closed down, however TERENA would continue to provide support for and streaming in the future, by promoting collaboration in the context of focused projects. In addition he recalled that TERENA owns two CAMvison-2 boxes that were donated by Litton/Carrier Access and said they were still available for testing, even for an indefinite time. 5. Definition of High Quality streaming and Every participant in the group was asked to define High Quality and streaming in terms of quality, encoding, latency and required bandwidth. The result is described in the following table. Edinburgh Low Quality High Quality / S-VHS, latency <50 msec MPEG-2 12 Mbps > CellStack 15 Mbps > vc and streaming for studio environment Very High Quality HDTV compressed 50 Mbps streaming / Desktop CIF 400+ Kbps / Glasgow / streaming / CIF 500+ Kbps RedIRIS MPEG-1 and MPEG-2, 2-4 Mbps, latency <50 msec / MPEG-2 12 Mbps> / streaming / MPEG-1 3Mbps> / SURFnet / H H MPEG-2 HDTV compressed 50 Mbps 4CIF + CD Audio 4 Mbps

9 latency <250 msec VR: HDTV * 4 (??) latency <10 msec streaming / MPEG-2 4Mbps> / HEAnet / MPEG-2 4Mbps> latency <50 msec streaming 22 Kbps CIF 800 Kbps> / FUNET / 576 lines (half D1) MPEG-2 2 Mbps> MPEG Mbps medium, MPEG-1 streaming / idem - full screen Real 800 Mbps> Geneva / MPEG Mbps latency <100 msec streaming / / / / 6. Open discussion and meeting wrap-up The open discussion started with an investigation into the need for information and reports about available Codecs. A number of products from different vendors were listed with the purpose of finding out who had experience or was able to access to information about them. The list included tools from the following manufacturers: Litton, Vbrick, Minerva, Optivision, VisioWave, Optibase, 2NetFX. All people who had tried the Litton CamVision2 codecs reported some negative experience. The Vbrick 3000 was not recommended too, mainly because of many artifact effects and poor lip-synchronisation with MPEG-1. There were some artifact effects also with MPEG-2, but lip-synchronisation was much better. However this codec was also buggy and had high latency. Egon said that people who had tried the Optibase MovieMaker Networking Edition were very enthusiastic and said that it should probably be

10 recommended, however he did not see a report yet and would ask people to provide some information about their experience. George remarked that in Scotland they want to look at High Quality working codecs only and they would probably try the Optivision first. A second topic for discussion was to identify critical issues to be addressed by manufacturers in their test reports. Those were: network - LAN, WAN, Point-to-point or multipoint, routers, multicast; latency, bandwidth; how packet drop is handled; framing structure; lip-synch; Codec type and interoperability; kind of supported encoding (PAL, NTSC); management/display tools; manipulation of the IP paramenters; how many incoming streams can be decoded; network management / scheduling tools etc; security; audio quality; audio spectrum of echo canceller 0-15 Khz; delay variance - ask buffer size. Before the meeting wrap-up the participants agreed on a number of areas where there is a clear need and interest for collaboration at the international level. These are: coordination of numbering plan for Europe - not limited to H.323; scheduling; firewalls. In addition the group felt the need for a system that can provide feedback about the quality of the artifacts that are sent by a participant in a conference. A participant should be able to self-test them before joining the conference to make sure that the perceived quality of the transmission is good. The group thought it was a good idea to start a common project to develop such a tool. The group agreed to follow-up with organising an informal workshop in some months from the current meeting. The minutes of this meeting would be drafted by Valentino and circulated inside the group with the aim of finalizing a document that would be distributed to the streaming list at TERENA. It was hoped that the further discussion would be beneficial to broadening the group.

11 7. List of actions 1. Egon to provide information about experiments on Digital Video over transatlantic links. 2. George to release the SMVCN draft document - DONE, online draft Study into Video Services in Scottish Higher Education. 3. Egon to contact David Lassner from the University of Hawaii about available public reports on Optivision - DONE.