Videoconferencing update

A. Flavell, Glasgow Univ.

For HEPSYSMAN meeting

Apr 2003

OverviewTechnologies

• H.323/IP, vic/rat, unicast/multicast; H.320/ISDN; Point-to-point, multipoint; data sharing (several offerings)

Services

• JVCS services bundle (mostly studio-class)

• UK campuses (sketchy...)

• ESnet (DCS, ECS) services bundle (USA AUP)

• VRVS services bundle

• Access Grid (AG) (sketchy, this time)

• GDS Global dial(l)ing Scheme

Kit, and client software

Technologies: protocols• H.323: industry standard for v.c. over IP, seeing

increasing deployment, from low-end up to studio class.

• Vic/rat: early apps from Mbone, still being used and developed by VRVS and by AccessGrid; unicast and multicast-capable.

• H.320/ISDN: the traditional v.c; is fading in our community, incurs per-use charges. Guaranteed bandwidth of ISDN was useful back when IP was congested – it's different now!

Technologies: contd.• All clients can make point to point calls without

additional help (but gatekeepers and directory servers may be useful; and you may need a gateway past a campus firewall)

• In general, multipoint calls require the use of an MCU (some higher-end clients can act as a mini MCU): MCUs are expensive and can be troublesome, not something you can buy and forget.

• Data sharing seems a most valuable service for our community, and seems as yet under-used: there are several offerings, maybe it's perceived as too complicated and confusing...

Services: JVCS• New H.323/IP service offering (piloted as

JIPVCS) is now in production as JVCS-IP.• JVCS = JVCSS (ISDN) + JVCS-IP (H.323)• http://www.jvcs.video.ja.net/docs/jvcsip.shtml • Booking system is much as before, but now

includes H.323/IP-based stations.• H.323 Kit was purchased centrally and deployed

to sites. This is 2Mb/s studio-quality kit. Kit includes local gatekeepers.

• Users with own kit (e.g Zydacron) may join via their campus v.c administration and gatekeeper.

JVCS continued• Kit must pass their QA tests. Our Zydacron was tested at

768k (with side-comments implying that anything less would be unwelcome) and was near their threshold of acceptability. It gets a fair bit of use – from a rather small user base as yet.

• Mixed messages about if and when desktops e.g ViaVideo will be accepted. But the service does include rate-matching, so this should be feasible if policy allows it.

JVCS also offers a quite separate data-sharing service, which they told me they're happy for anyone to use. This uses the data sharing component of Windows NetMeeting. See http://jvcsbook.ja.net/docs/datash/

UK CampusesVarious campuses have own v.c arrangements

additional to JVCS, but I have only limited details. Examples only:

• Glasgow has MCU facilities (heavily committed for teaching); also an H.323/ISDN gateway - permits H.323 clients to make or receive H.320/ISDN v.c and voice-only (phone) calls.

• UCL has an H.323 MCU, which Grid project users regularly make use of (by arrangement, of course).

ESnet• N.B ESnet AUP requires USA participation in

principle (some special cases e.g DESY)• Traditional offering: DCS bookable H.320/ISDN

conferences. Also voice-only conferences.• Experimental H.323 link (801234) was implemented

but died. Temporary arrangements now, until ECS bookable service operational: each H.323 user books a GUEST slot and uses ESnet ISDN gateway to call it from H.323.

• New offerings under the "ECS" banner, http://www.ecs.es.net/

ESnet ECS• Ad-hoc H.323-only conferences: NOW. Currently

approves only hardware-based codecs.• Audio conferences: NOW (replaces old audio bridge

service).• Data sharing: NOW – it works (via proprietary browser

applet, but claims to be T.120 compatible – details unclear)

• Integrated bookable H320/ISDN + H.323/IP sessions to replace DCS: new booking system being trialled now, actual service seems to be some months off yet.

Users of ECS services must in general register for use beforehand. Unregistered users cannot simply walk up and get service (there seem to have been some misunderstandings in the recent past.)

ESnet user experience• Our CDF users have used DCS successfully via H.323

gateway for a long time.

• They are also early adopters of the ECS ad-hoc H.323 facility and use it frequently.

• This with our Zydacron, or with ViaVideo (software version 2.2, NOT version 3.0).

• Also gets used from laptop on wireless LAN

• The ad hoc MCU does NOT have rate matching, and requires G.711 64k for audio: it works well from a colleague's home 256k cable connection, but from another member's nominal 128k cable it was pretty much unusable.

Note about DESY and ESnet• DESY manage their video room bookings via the

ESnet system• DESY/HH rooms are H.323-capable (the IP

addresses are on the room's DCS page)• Zeuthen (? I got mixed messages ?)• When booking for a point to point connection to

DESY, the DESY contact will book the room in the DCS booking system: take care not to reserve unnecessary H.320 MCU slots at ESnet (this has happened several times due to misunderstanding).

VRVS • VRVS enhanced and expanded: VRVS3.0• Users must now register and assign a password• Several dedicated communities. Users outside

those communities register in Universe• Service offerings as before: browser-based control

panel, vic/rat, H.323 etc., chat window, data sharing via VNC.

• Browser compatibility improved for a wider range of modern browsers.

• ViaVideo users still need viavideo software version 2.2 NOT 3.0

VRVS user experience• Experience with the new VRVS version seems pretty

good.• Chief problem with VRVS is folks using random PC

hardware. Every PC seems to come with a different audio card, webcam, different drivers, bringing new bugs and glitches.

• Using ViaVideo (v.v software version 2.2) gives more predictable results.

• Also, VRVS users tend to be occasional, and will tear-down their setup after use, then forget which plug goes where the next time. Reckon on at least 10 minutes – sometimes a lot more - for setup time before productive meeting starts, unless users are experienced, or willing to take time for a pre-test session.

AccessGrid• An ambitious continuous-presence studio-based

offering.• Based on IP multicast (this still causes some

problems at the edges. There exist multicast relays, but they don't seem ideal).

• Our users seem much more interested in the low-end desktop offerings that allow informal day to day contacts without having to book and go to a special room.

• So I haven't much to add to the previous report on this mode, sorry.

GDS: Global Dialling Scheme• A world-wide dialling scheme for H.323 analogous to

international telephone dialling, see http://www.jvcs.video.ja.net/docs/jvcsip.shtml#010 or http://www.unc.edu/video/videnet/faq/

• JVCS-IP participates in the scheme and uses it itself, and I've tested it successfully via the campus gatekeeper

• Example 004401158215454: 00 = international prefix, 44=GB/UK, 01158 is JVCS->Glasgow Univ., and 215454 is our Zydacron (while registered to the campus GK)

• ESnet doesn't use the scheme internally, but is connected to it and can call with appropriate prefix (I've tested this successfully also).

An apology (again)

• Videoconferencing options are complicated• This is not of my making: I'm doing my

best to show ways through the maze• Conferencing is working well for some

groups of users. And it's cheaper than the telephone, once you have the kit. So why not give it a try?

• Don't overlook the benefits of data sharing…

H.323 configuration Tip• We need to configure to different gatekeepers (campus,

ESnet, UCL) according to usage;• Each gatekeeper wants a different E.164 identity and/or

alias;• Damned nuisance to reconfigure via the client GUI every

time we need to change.• Take copies of the relevant configuration file for each

configuration, and write a script (batch file etc.) to plug the desired one into place and fire up the client software.

• The file is typically (also for Zydacron) called "Config.val" in the same folder as the installed application, e.g C:\Program Files\Polycom\Viavideo

• Create entries on your start menu for the various configs.

Kit and software• There are no new purchase recommendations this

time.• ViaVideo can be recommended as before: but use

software version 2.2: version 3 causes problems with VRVS and with ESnet ad-hoc H.323.

• Zydacrons are still in productive use, but we don't recommend purchase now.

• Thus there is no concrete recommendation for group-sized gear. Ask your campus support about calling-off from the JVCS-IP procurement contract? (Tandberg)

Purchase (2)• If only VRVS is required then anything which supports

vic/rat will do (webcam etc) but beware of kooky audio.

• For H.323, find out whether software codecs (e.g NetMeeting or GnomeMeeting) are acceptable to your MCU provider, or not. (Usually "not").

• ESnet H.323 saturation test (USA) showed that the vast majority use ViaVideo.

• It's looking as if GnomeMeeting might be accepted by ESnet ad-hoc later, but for now only hardware codecs are approved (e.g viavideo).

• Hardware codecs generally support only Windows OSes.

• ViaVideo security alert.

Purchase (3)• Software is either bundled, or comes free

from the service provider (VRVS package, ESnet data sharing applet, etc.) so there are no additional costs there.

• Audio kit is a weak spot with us. We use the inexpensive SoundPoint/PC, which is OK though its connectors are unreliable. Better audio kit would be nice – but rapidly gets very expensive. I don't personally have any recommendations, sorry.

Conclusions• Desktop videoconferencing is working for the community

and some (e.g in CDF) say we couldn't have survived without it.

• There are some glitches, unwanted complexity and duplication of service offerings, but these are not of our making.

• For studio work we still look to our central campus service. Some other groups have own investment in kit.

• I still feel that data-sharing is under-used, maybe because of the different service offerings and user perception of complexity, but I'd recommend taking another look.

The End