- 1. Videoconferencing update A. Flavell, Glasgow Univ. For
HEPSYSMAN meeting Apr 2003
- H.323/IP, vic/rat,unicast/multicast; H.320/ISDN;
Point-to-point, multipoint; data sharing (several offerings)
- JVCS services bundle (mostly studio-class)
- ESnet (DCS, ECS) services bundle (USA AUP)
- Access Grid (AG) (sketchy, this time)
- GDS Global dial(l)ing Scheme
3. 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!
4. 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...
5. 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)
- Booking system is much as before, but now includes
- 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.
6. 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
7. UK Campuses
- Various 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).
- N.B ESnet AUP requires USA participation in principle (some
special cases e.g DESY)
- Traditional offering: DCS bookable H.320/ISDN conferences.Also
- 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"
9. ESnet ECS
- Ad-hoc H.323-only conferences: NOW. Currently approves only
- Audio conferences: NOW (replaces old audio bridge
- 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
10. 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.
11. 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 enhanced and expanded: VRVS3.0
- Users must now register and assign a password
- Several dedicated communities.Users outside those communities
- 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
- ViaVideo users still need viavideo software version 2.2 NOT
13. 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
- 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.
- 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
- 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,
15. GDS: Global Dialling Scheme
- A world-wide dialling scheme for H.323 analogous to
international telephone dialling,
- JVCS-IP participates in the scheme and uses it itself, and I've
tested it successfully via the campus gatekeeper
- Example004401158215454 : 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
16. 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
17. 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
- 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.gC:Program
- Create entries on your start menu for the various configs.
18. 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 VRVSandwith ESnet ad-hoc
- Zydacrons are still in productive use, but we don't recommend
- Thus there is no concrete recommendation for group-sized
gear.Ask your campus support about calling-off from the JVCS-IP
19. 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
- ESnet H.323 saturation test (USA) showed that the vast majority
- It's looking as if GnomeMeeting might be accepted by ESnet
ad-hoc later, but for now only hardware codecs are approved (e.g
- Hardware codecs generally support only Windows OSes.
20. 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.
- 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.
22. The End