I See You. And You. And You.

 
 
By eweek  |  Posted 2001-05-21 Email Print this article Print
 
 
 
 
 
 
 

Need to conference with several sites at once? Here are two all-in-one solutions that can help out.

These days, point-to-point videoconferencing has become, well, a commodity. There are lots of products available that transmit video between two sites. But for the operation thats spread out all over the place and needs to confer among multiple sites simultaneously, the list of potential solutions rapidly dwindles. There are fewer products available, and successful solution implementations require more integration effort. Thats because as the contractor, youre dealing with a large number of factors that affect the delivery of packets between the sites.

Packet-based video transmission has varying bandwidth needs. For example, during our evaluation, we took a look at the bandwidth consumption on just one call in real time. For a stationary image with no audio, the nominal data rate was about 78Kbps. Then the person in the image (James, in this case) began to move and talk. We watched bandwidth jump to 320Kbps—and stay there. Once James stopped moving and speaking, the data rate fell back down below 80Kbps. Now multiply our results by three or four, and you can see some of the bandwidth challenges that youll be facing.

The units we looked at are crammed full of features. Both vendors have data sheets that one might drool over. Do you need all of the bells and whistles? Maybe, maybe not. But its nice to know that theyre there in case you do. At any rate, the extra features dont get in the way of the basic functions of the devices.

In fact, some of the features seem to be growing in popularity over the "traditional" videoconferencing functions. Andrew Davis of Wainhouse Research (www.wainhouse.com) sees considerable growth in multimedia networking infrastructure. He projects that gateway, gatekeeper and multipoint control unit equipment shipments alone will increase from $375 million in 2000 to more than $1.25 billion in 2005.

In a recent report, Davis concludes that the combination of audioconferencing and Web conferencing products—with a five-year compound annual growth rate (CAGR) of 30.7 percent—will outpace video-centric conferencing products, predicted to grow 21.9 percent annually. Audioconferencing will be spurred by intense growth in the Web conferencing market, with Web server products forecast to exceed 50 percent CAGR in terms of revenues, and more than 80 percent CAGR in terms of number of users.

And Perey Research & Consulting (www.perey.com) predicts strong demand for IP-based videoconferencing products over the next four years, forecasting nearly $1.5 billion in revenues by 2004. "Those who purchased videoconferencing products in 2000 indicated a nearly unanimous interest in having their video transmitted over packet-based [IP] infrastructure," said Christine Perey, president.

Our criteria was to find IP-based units that had built- in multipoint control unit (MCU) capability. Simply put, MCU capability permits a conference session among two or more parties, simultaneously. Sure, there are devices that perform just MCU functions, but we wanted to see what was available in the "all-in-one" form factor. We werent disappointed. The two units that we looked at (Polycoms ViewStation FX and Tandbergs 800) have a huge set of features in common.

Each is a fully featured room-oriented system—you wouldnt be deploying these devices to desktops unless your client is still enjoying a dot-com bonus. Both boxes implement many of their features in software, so its likely that the bells and whistles provided by one vendor will show up in the next vendors release. Its a "tit-for-tat" situation. Here are some of the differences between the units.

ViewStation FX Its amazing what Polycom packs into a very small footprint device. The ViewStation FX is heavy on the performance and collaboration feature front but effectively masks all the technology with an easy-to-use user interface.

While the FX comes standard with a 10/100 Ethernet connection, it pumps a lot of data through the pipe: a whopping 2Mbps. This becomes important as multisite conferences become more complex, with more moving images and people talking, not to mention presentations flying and being streamed hither and yon.

A built-in 10/100 hub in the unit allows for a second PC to be networked to the FX, which can be used for presentations and group collaboration. The base unit has no ISDN or V.35 capability; optional network interface boxes provide PRI T1 or V.35 interfaces.

Thats OK with us; we cant wait to get rid of ISDN. Unfortunately, the rest of the world doesnt quite feel the same way, so sometimes your customers might have a need to use ISDN to contact someone. The FX can do it, but itll just cost a little more.

Well sing strong praises for the ViewStation FXs user interface, or UI, which is heads and tails more intuitive than the menu system found on the Tandberg unit. Polycom clearly has spent a fair amount of time figuring out how to make the process of driving the FX as simple as possible. Case in point: the use of icons in the setup process, which make configuration less difficult. And during operation, the UI presents just a few choices to the user. Selecting the function is as simple as highlighting the icon and pressing the button in the middle of the arrow-key complex on the remote control. The remote control, too, deserves some mention—you can almost completely control the system with your thumb. Not quite, but almost. Buttons are different sizes and colors, so that you can, with some practice, begin to memorize where key functions are located.

Polycom has done a great deal of integration to make the ViewStation easy to use with popular PC presentation applications, specifically Microsofts PowerPoint. Its very simple to point your Web browser to the FX, select "view a presentation," from a list of presentations available in the FX, and start viewing. The setup on the other end, where a PC is "presenting" slides to the FX, is equally simple. Point the browser to the FX, choose "select a presentation," choose a presentation from the dialog box, and the FX takes it from there, loading thumbnails into its memory and setting up the necessary associations between the FX and the PC for the presentation.

Tandberg 800 If the FX was queen of speed and collaboration, the Tandberg 800 is king of connectivity. To begin with, the unit comes with an Ethernet connection, as well as three ISDN BRI interfaces. Our sentiments concerning ISDN notwithstanding, this is essential if even the glimmer of a thought of using this type (H.320) of communication is contemplated. The 800 also sports a V.35 interface as standard equipment, which is an option on the FX.

Continuing on with the connectivity theme, the 800 allows for up to five connections in a conference—you, three other video sessions, and a single ISDN audio phone call. And one of its bonuses is that the conference initiator doesnt have to do all the dialing. The 800 allows for other sites (up to the maximum) to "dial" in to the conference as it is progressing. You can bet that someone wont be ready at the other end, and the "phone" will keep ringing. Thats a huge timesaver for the person hosting the conference, even though both the 800 and the FX can create, store and dial conference groups with one key.

Another feature that Tandberg touts is its Duo Video feature, which sends an image (from a document camera, for example) to a second monitor at the other end(s) of the conference, if theyre equipped with the same Duo Video feature. Sounds good if youre connecting up to many conference rooms, but if youre meeting with people at their desks, the utility is lost on us.

Were also finding that its easy to get lost in the Tandberg 800s maze of menus. The system by which the 800 is configured is confusing and difficult to maneuver both in and around. Add a remote control that requires two hands to operate, and youve got a recipe for disaster. The Users Guide is quite clear and specific regarding the menu hierarchy, but this is still more difficult to operate than the ViewStation. Much more so.

Its not harder to get PCs, or any device that can output to an RS-232 port, hooked up to the 800. So while the Tandberg unit isnt as PowerPoint-friendly as the FX, you easily can route the output from, say, a Linux box to the 800. The RS-232 port also switch-hits as a T.120 communications port, a data port and a control port for the unit. Wed like to see more robust T.120 support. NetMeeting at 38.4K? Ouch. Theres also a VGA input port on the 800 for hooking up the laptop and using whatever presentation package you wish, just as long as youre comfortable with controlling the PC manually.

Rocky Road Ahead Making these boxes work is the easy part. Its sexy, even fun, but make no mistake: H.323 (IP) videoconferencing is a Pandoras box—open it and feel its wrath.

So whats the problem? Videoconferencing is a bandwidth hog and its real time, which wasnt an issue in the early days when ISDN ruled—providing guaranteed, dedicated bandwidth—but IP is a whole different story.

IP is shared and unless you keep a pipe the size of the Titanic open, your clients network will grind to a halt.

Chances are youll deploy videoconferencing where the network cant handle the load. This presents some serious opportunities, such as upgraded pipes or better yet, an entirely new IP network just for videoconferencing—not such a bad idea considering that a single, good-quality videoconference easily swallows up a minimum of 768Kbps (with full-duplex audio and video).

You must calculate the networks current bandwidth usage and how much videoconferencing will impact it. A videoconference that stays within the corporate network is one thing; connecting to sites out on the Internet is another because its impossible to control the pipe. But you can control other things.

Remote management is always a concern, especially when the only discernable interface is a television monitor with a remote control. Fortunately, each of these units come with Web-based administration and a plethora of diagnostic aids.

Besides throwing in more bandwidth, install a gatekeeper. It will grant or deny requests for bandwidth from H.323 end points based on bandwidth allocation limits set by you. That way, no videoconference can gobble more bandwidth beyond the predefined limits. Gatekeepers also perform address translation and perform admission control, controlling network access to the end points.

Another bandwidth-saving feature we used on both units is multicast streaming. This is especially useful when the recipients of a conference do not need to provide feedback or can do it by audio, such as a corporate town meeting.

Oh, and we hope you havent forgotten. Theres the firewall and network address translation (NAT) devices to be dealt with.

One reseller we spoke to, Peter McCutchen of GBH, which specializes in videoconferencing, says in most cases its better to put the videoconferencing equipment outside the firewall in the DMZ. It makes it easier to configure and doesnt open up any security holes.

H.323 videoconferencing uses port 1720 to establish the connection and then ports 3230 through 3235 to transmit the data. While there are H.323-aware firewalls, which will pass only H.323 traffic, most of them require opening those ports to all traffic. Not a severe security risk, but why take chances?

NATs are an entirely different matter, but equally as poignant. H.323 end points require a one-to-one connection. That means they need their own Internet routable IP address (unless all of the conferences take place within the clients network). These units can work with the NAT—the Polycom ViaVideo desktop units even auto-discover the outside IP address—but you must configure the NAT device to map the H.323 ports to the back-end device, which means for every end point behind the NAT there must be a unique Internet routable IP address. Another sticking point is that a unit configured to work with a NAT device cant also be used to conference within the network—its either one or the other.

Weve been primarily focusing on H.323, but legacy H.320 (ISDN) videoconferencing units are out there in droves and they need to interoperate with the IP-based units. The best way to do this is by deploying a gateway (not to be confused with the gatekeeper mentioned above). Gateways link H.323 conferences to H.320 end points, as well as to PSTN terminals (H.324).

When deploying videoconferencing, we like what McCutchen keeps in mind. "Its the client, stupid," he says. "Meetings are about people, not about technology."

Everything must work in harmony and all of the end points must be easy to use. In other words, make sure you put in client time to ensure theyre comfortable with the systems, rather than focusing solely on the technology.

 
 
 
 
 
 
 
 
 
 
 

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