The Rapidly Changing Future of Videoconferencing
Systems
It's all about H.320 versus H.323
We knew as we involved ourselves in this project that the rate of
change in video technologies was increasing. In FY 2000, the industry has been moving from H.320 to H.323 standards. That change
doesn't sound like much, but it can make a world of difference if
you don't know what you're buying into. (Recall that H.320 systems
are the more traditional video-conferencing systems that run over
dial-up ISDN telephone lines or dedicated network connections, and
that H.323 is the up-and-coming IP-based (Internet) standard).
We purchased H.320 systems because:
- We felt the technology was more proven and we needed to start
out with some quick successes. The relatively high complexity of
ISDN services in a rural setting (where the telco's don't have much
experience with ISDN) led to a host of network failures. Some of
our own staff had to invest a great deal of time debugging network
failures involving at least four if not six or eight competing
network providers. Some staff felt the project was a low priority
activity so they ignored calls for technical help. These issues
completely killed the "early win" objective. Our faculties' early
experiences were filled with outages which have since been
eliminated, but the goal of some early and quick successes was
missed.
- Most of the world is still using H.320 systems so if we want to
bring in outside speakers, conduct hiring interviews, etc.,
then we need compatibility. This remains an admirable goal, so if
you're drawn to H.323 systems, plan for a means to connect to the
H.320 world out there (an H.323 gateway). Still, do NOT assume that
if you have H.320-compatible systems that you can schedule a video
conference with an outside site without testing your connections.
For busy support staff, this can take days to schedule, even weeks.
Look at our policy statements.
- We knew we could plan for both dial-up ISDN connections and
dedicated network connections. Technically this is true, and we
rely generally on our dedicated connections between Denison and
Kenyon for most of our work, but when the network connection fails,
our faculty have opted to end the session rather than re-establish
connections with the ISDN services. The process at its best takes 3
minutes in about four steps (touches on the touch screens), but at
its worst, simply can't be done without experienced technical
support.
We will buy into H.323 Internet-based systems in the future
because:
- While the networks are very similar, H.323 makes the video into
DATA and IP-based data is something our staffs work with each day.
The telcos are getting better at managing data connections as well.
For example, you can monitor data connectivity with more common
tools than you can video connections.
- Most vendors are now marketing H.323 video systems. Take a
look, for example, at Polycom's
Viewstations that were used in the recent Ohio Video Intranet
Conference at which the Ohio Learning
Network announced an ambitious plan to promote and support
video connectivity state-wide for higher education. For about
$8,000, one can set up a 30 frame per second H.323 classroom system
with controllable camera, codec (to digitize the analog video into
data) and a 36" monitor. (Don't forget that you'll need a 10 Mbps
ethernet port in the classroom).
- We will be able to connect our existing H.320 systems into the
dominant IP-based networks using $4,000 gateways (computers that
convert signals such as
RADvision's video interface units).
- Desktop video systems (cameras like VCON's Escort and Cruiser systems) will
enable our faculties and us to join in video sessions, to connect
visually to each other, and more. H.320 systems are too expensive
as desktop solutions. Consumer level desktop cameras (USB or
parallel port connections, under $150) simply don't have the
horsepower to join into "real" video conferences.
- ...and as other H.323 products come onto the market, some will
spark new ideas for uses in the academy.
Update
As of March, 2001, we've upgraded the facilities at Denison University and added some new capabilities. First, we bought a RADVision video interface unit (VIU) so that our Tandberg Educator 5000 system, with all its ease-of-use features, can connect with H.323 sites. We've also added a portable unit to our inventory: a PolyCom Viewstation SP (about $4,000). This system is capable of both H.323 and H.320 conenctions, but we're using it to move around the campus IP network for video conferencing where we need it. Finally, we bought some PolyCom ViaVideo desktop systems (USB connections, Windows 2000). Quite frankly, the video conference sessions that we've had so far over the commodity Internet have been excellent.
Further questions?
Please contact Scott E.
Siddall, Director, Mellon Program at Denison and Kenyon.
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