Videoconferencing: recent User Experience A. Flavell, Glasgow University March 2001

A.Flavell, HTASC Equip(1): Room-based Dedicated room, providing H.320/ISDN, H.323/IP and/or ATM. Data sharing (T.120) sometimes available Costs GBP20,000+ Provided centrally in our University Has to be booked. Often clashes. Good quality, but out of our price range Not really considered further in this talk.

A.Flavell, HTASC Equip(2): ‘Business class’ PC-based system with dedicated hardware Costs start at GBP400 (ViaVideo), 1K (Zydacron OnWAN, or VCON equiv), plus PC and display. Supports H.323/IP and maybe H.320/ISDN2 Data sharing (T.120) available, usual Win/PC apps, unix windows via X server such as eXceed Good echo cancelling Full-screen video when desired Typically PC-on-a-trolley; group of 4-6 quite feasible

A.Flavell, HTASC Equip(3): ‘Cheap and cheerful’ PC with cheap video capture GBP (we chiefly use Videum/AV under Win/NT4). Linux also feasible (with vic/rat): we don’t - others do. Use either NetMeeting or vic/rat (VRVS) Data sharing (NM); whiteboard and chat (VRVS) Work done in CPU. Limited video window size Relatively poor audio, no echo cancelling (use headset, or use Polyspan Soundpoint/PC GBP75). Can afford to fit kit to many users’ PCs Suitable for one person, or group of 2-3 at most

A.Flavell, HTASC IP v. ISDN ISDN guarantees bandwidth, but expensive (ISDN2 = 128kb/s) IP cheap, but non-guaranteed bandwidth: typically we’ve been using 384kb/s. Some sites still only support ISDN, so availability of a gateway is very beneficial. The trend is definitely towards IP, though.

A.Flavell, HTASC H.323 v. vic/rat (Mbone/VRVS) Vic/rat developed for Mbone (multicast) use, but they also operate in unicast mode. Require only limited CPU resources. H.323 international standard. All the hallmarks of design by committee. Increasingly supported by industry. Good performance needs dedicated hardware, but software-based apps are catching up. Definite problems with firewalls. NetMeeting v3 is meant to be H.323, but some interworking problems are experienced.

A.Flavell, HTASC Scenario 1: H.323 pt-2-pt Between ‘business-class’ stations this works great; in practice, most of our use has been multipoint however Between NetMeetings, it works acceptably, and users are often doing it between their personal desktops (Glasgow-FNAL, Glasgow-CERN: not to DESY because of firewall) Netmeeting ’business class’ connections can be troublesome, we found. Can use an MCU as intermediary, but still not trouble-free.

A.Flavell, HTASC Scenario 2: H.323 multipoint RADVision H.323 MCU in Glasgow (comp.serv) ditto in videoconf. facility at UCL (London) Development Accord MCU at ESnet All work well with ‘business class’ gear T.120 data sharing ‘on top of’ MCU call RADVision works OK with NetMeeting, some suspicion of extra problems due to NM Some problems with NetMeeting, and especially when mixed (ESnet awaiting software fixes for NetMeeting)

A.Flavell, HTASC RADVision H.323 MCU usage RADVision can offer an informal option in which users define their own sessions by a session profile (e.g 61 = medium quality, max 5 users) and a chosen key, without further formality they all call 6142 and are connected together. Quite a number of meetings have been held on these MCUs in the last half-year or so. NetMeeting audio was found troublesome. In silent periods an intrusive motor-boating is often heard. Doesn’t happen if only ‘business class’ equipt is used.

A.Flavell, HTASC Scenario 3: mixed IP/ISDN The only real-user experience has been with ESnet Interim solution: Production (ISDN) Accord (so- called “DCS” service) is bridged via ‘room’ ESNET-TEST-1234 to the development Accord H.323 facility New pilot: both ISDN and IP are serviced on the dev. Accord, working towards new production system. Scheduled via WebCommander.

A.Flavell, HTASC ESnet... Usage: several sessions using ESNET-TEST- 1234, has become practically routine. Used by our CDF and ZEUS users. Tel Aviv also joined via H.323 for some meetings. Other sites (even US) interested in moving to H.323 to save call charges. Results are very good, except for high latency. Data sharing was not used in these meetings. New pilot system used quite a bit during testing, but not really by users yet. Latency reduced. Some worries about using NetMeeting.

A.Flavell, HTASC User reactions I’ve been trying in a small way to promote PC- based videoconferencing for quite a number of years: until recently, without much success. Within less than a year, usage of the one (now two) ‘business class’ stations, and of some half- dozen equipped desktop PCs has “taken off”, and users want more. Experience with the rollabout system and access to remote MCUs means that users see it as a real alternative to using the central room-based system.

A.Flavell, HTASC User reactions...(2) Despite the inferior quality, users value the ‘cheap and cheerful’ NetMeeting or VRVS from their own desktop thanks to its informality and the availability of data sharing to show their work. ‘Cheap and cheerful’ video is mainly for ‘presence’, rather than for showing information. One UK site keeps trying to use NetMeeting to interwork with ‘business class’ users, but this proves less satisfactory and brings complaints from other sites - as our own tests also showed.

A.Flavell, HTASC User reactions...(3) The basic Zydacron OnWAN Z350 kit can serve as a basis for enhancement as required, as it has external inputs for a better microphone, camera etc. Also a cordless keyboard/mouse can be recommended. The relatively inexpensive ViaVideo (as seen elsewhere) is self-contained and has no external inputs. Its advantage is that, being USB- connected, it can be easily moved from one PC (e.g desktop) to another (e.g laptop).

A.Flavell, HTASC User (non)-reactions New VRVS with H.323 interworking has been tried a bit by me but not by our users. Seems a good idea as a transition aid, if it works reliably MBone has been completely re-engineered in last couple of years and is now working well; but users aren’t exactly clamouring to use multicast. RealNetworks sessions have been well received, but we haven’t tried to initiate any ourselves. I’ve looked at OpenH323 and it looks promising, but not practically usable yet.

A.Flavell, HTASC Conclusions (1) Both ‘business class’ and ‘cheap and cheerful’ have useful roles to play PC videoconferencing seems to have taken-off in last half-year with our users Fragmentation is unfortunate (H.320/ISDN, H.323/IP, vic/rat, RealNetworks, Windows/Linux) but not of our making, and not really avoidable. VRVS has been and is useful from personal desktops. Until OpenH323 is ready, how else to interwork with linux etc. systems?

A.Flavell, HTASC Conclusions (2) We’ve been very pleased with our Zydacrons, but better camera and microphone would be nice Good audio is more important to users that good video - which often is only used for ‘presence’. Data sharing is an extremely useful tool, and often missing from room-based setups Other key components are MCUs, gateways and scheduling systems, but here we have been relying on services provided by others.