May 21, 2007 Update:  See the latest comments on my bridge here.

Please note this was originally written in May 2006 and versions have changed since then. See the comments section for TANDBERG’s response. – Note added March 2007.

First Things First
First before I write about some comparisons, let me describe my base assumptions and biases.

1. My use of videoconferencing is almost totally connecting with
“unmanaged” units, or places outside of my service area. These are
other schools that connect in a myriad of ways, and who don’t
particularly want to be registered to my gatekeeper, because I connect
to them only once or twice a year. Some connect through bridges
(Radvision, Polycom MGCs, old Accords, etc.), some connect directly,
some connect via IP, and some connect via ISDN. Read Across America, MysteryQuest, and other such projects and events are what we do with videoconferencing. Hence
I connect with a ton of unknown units all the time. And I expect that
to work consistently (with a test call ahead of time of course!).

2. As an educational service agency supporting videoconferencing, I
expect my MCU to be able to connect to anything. My goal with my MCU is
to provide services and connections to my districts that they could not
do on their own: multipoint events, IP/ISDN conversion, connections
they can’t make on their own.

And some background. I have 35 (soon to be 70) Polycom endpoints and a Tandberg
MPS (vJ3.0), gateway, gatekeeper and Tandberg Management Suite (TMS). The comparison is with my colleague Arnie Comer‘s
bridge: an Polycom MGC 100 and he supports 140 Tandberg endpoints. We both use our bridges as described above.

This comparison is not on all the features that either bridge can
do, but on the features necessary to support K12 videoconferencing as
described above.

Comparison

So I have come to the conclusion that the Polycom MCU is the
workhorse of videoconferencing, connecting all types of units together.
The Tandberg bridge seems to be heading towards a closed network model
with great wonderful fancy features for closed networks. But it does
not handle IP address dialing well at all and the company
doesn’t seem to be designing their systems to support IP address dialing.

Disclosure Statement: Polycom is sponsoring the BCISD Videoconference Program Database. They also link to my blog. However, they do not dictate, edit, or preapprove anything I write here.

A few weeks ago I followed with interest a Megaconference listserv discussion about LifeSize and it’s support of video protocols. Here is a comment by John S. Martin, from the JANET Videoconferencing Management Centre, University of Edinburgh.

When multipointing in a multi-user environment we have found several incompatibility issues which are only resolved when one, or all, of the connected codecs connected at H.261. This is the base standard for H.323 videoconferencing. Yes, a video protocol transcoded conference will overcome this issue, but this uses more resource on an MCU such as a Polycom MGC. I
have spoken to lifesize about this and apparently it was a commercial decision not to implement H.261, but something they may look at in the future, depending on demand.

I just find it bizarre that a company have developed a system which doesn’t connect to H.261/3/4 video protocols.

Usually I’m not thinking much about video protocols, but I was very interested in this conversation. The Megaconference listserv has many international higher ed technicians and I learn a lot just by reading the messages. It was intriguing because some people thought it didn’t matter. Why would a high definition VC product want to connect to a low end legacy product that could only do H.261?

This conversation concerned me, coming from a K12 VC environment where usually there is much less tech support. Some districts have a teacher who is responsible for the videoconferencing equipment, and that’s it! That teacher or media specialist expects the connection to work if it’s IP or ISDN and they usually don’t know anything about the video protocols. It’s enough to remember H.323 or H.320! As K12 endusers, we just want it to work! You want to be able to talk to someone, find out if they have videoconferencing, and have it work!

So I have a few thoughts and reflections based on this experience.

Learn From Others! If you participate in Megaconference or Megaconference Jr., stay on the listserv after the event is over! Even if the conversation seems like it’s way over your head! That’s how I felt when I first participated in Megaconference a few years ago. But I’ve stayed on the listserv and “lurked” and learned a lot about the technical back end details of videoconferencing that I wouldn’t have learned otherwise. Another good place to learn about technical details is the VTC Talk Forums.

Talking To Your Vendor. If you’re new to videoconferencing and are talking to your vendor, there are some things you should consider. Some of this advice is based on experiences with connecting to other schools for MysteryQuest, Read Across America, and similar projects. 9 times out of 10 your vendor will not have imagined these types of uses of videoconferencing and so may try to convince you otherwise.

1. You definitely need to be able to dial out to an IP address. And if possible, you need a way to get to ISDN sites as well. Not all of the providers have switched to IP yet. And some schools that you might want to connect to are also ISDN. Sometimes your educational service agency (ISD, BOCES, ESC, etc.) can provide this service for you. Or your vendor may have ideas of how you can get access to ISDN if needed. ISDN usage in K12 videoconferencing has diminished greatly in the last year or so, but if you truly want to be able to connect to anyone, you’ll need a way to convert to ISDN occasionally.

2. Second, you really need to be able to receive calls, preferably to an external IP address. There are a few content providers who prefer to call the school they are connecting to. There are also many great projects you can do with other schools. But if you partner up with a school that can only call out, and you can only call out, then you are stuck! This is a big problem in the Read Across America project and spin off projects that use the same format. There are new firewall traversal units coming out to help schools with the challenges of IP videoconferencing. However, sometimes these tools create an environment where you have to dial an extension to get to the right unit. Some schools connect through a bridge, and the bridge can’t dial an extension. All these things complicate projects that should be able to happen easily! So if at all possible, design your system so that you can receive calls to an external IP address. Otherwise, you may need your educational service agency to help you make connections with other schools.

3. Have as little as possible in between your VC unit and the rest of the world. In my experience with IP calls, the more “boxes” (firewalls, gateways, bridges, & stuff) are between two units, the lower the quality of the call. If you are in a consortium, design your system so you can make calls with or without the assistance of a central bridge. It’s good to be independent of that bridge if at all possible. I’m finding that my calls work better and have clearer pictures when connected directly. Some of the newer units can do beautiful H.264 calls that look great! But not all the bridges and gateways and stuff in between allow that protocol through.

H.323 has made videoconferencing cheaper and more accessible to schools, but it has also added a level of complexity to connections that is sometimes hard to navigate. But that’s the nature of the beast these days it seems.

Just ran across this interesting blog entry, Polycom Rocks…. A learning technologies conference in Australia gave away PVX software and a free webcam to the participants! What a great idea! Wish I had attended! I also heard recently that the state of California negotiated a statewide license for PVX software for education.

I’m very curious how these entities will be using their PVX software. It’s interesting how this top notch quality product blurs the lines between “room” videoconferencing and desktop videoconferencing with tiny web screens and tools like Skype & Festoon. With PVX and a little Logitech webcam you can get a full screen high quality H.323 videoconference that looks amazingly good!
While I have reservations about schools jumping into VC with PVX instead of a regular VC unit, I’ve recommended this to one of my tiny private schools that wouldn’t be able to do videoconferencing otherwise. It’s a bit of a stretch to use PVX with a room full of kids, but with a small class size of 15 or so, it’s almost manageable. The challenge is the microphone is designed for use by one person at a computer, so students have to come up closer to the computer to connect. Not ideal for projects like Read Across America and MysteryQuest, but doable.

On the other hand, the PVX solution is GREAT for meetings, quick conversations with colleagues, and for monitoring conferences from my office! Now in theory I can watch three conferences at a time with a VSX7000, a Viewstation, and PVX on my laptop.

I wonder what is next in the convergence of videoconference technologies!