Tune in to IP videoconferencing

Tired of traveling, but still feel you need face-to-face meetings with remote associates? Videoconferencing may be the answer, but make sure you ask some hard questions of the vendors who want to sell you equipment. Just as important as video and audio quality are management, a user-friendly interface, data-sharing capabilities and interoperability.

Today's workgroup systems are turnkey solutions that support the two most frequently used standards for business videoconferencing: H.320 for video over ISDN and H.323 for video over IP. Packaged with everything but the network, workgroup systems include a PC, preloaded software, camera, wireless keyboard, microphone, speakers and monitor and can be installed in conference rooms or on the desktop.

How we did it We examined each system utilizing ISDN and IP transport. We also studied each system in four different connection environments: point-to-point calls between other commonly used ISDN systems; multipoint calls through Multipoint Control Units; H.323 (IP) calls point-to-point to other IP based systems; and Internet calls placed through an IP to ISDN gateway. To evaluate audio quality, we installed the systems in multiple locations to simulate favorable and less favorable videoconferencing conditions. We tested the audio signal received at the far end as well as the output on the system end. In addition, we polled a group of veteran videoconferencers for their opinions of system audio quality. To test the user interface, we asked several technical and nontechnical users to try to place a call and manipulate some of the system's basic features. In our test environment, we established IP calls over 100M bit/sec dedicated, 10M bit/sec dedicated and 10M bit/sec shared connections to see how network traffic affects a video call.

Of the three workgroup systems we tested, Intel's TeamStation System 4.0 Update 2 scored the highest due to its consistently high video quality and data-sharing capabilities. VCon's MediaConnect 8000 Version 2.5.1 demonstrated the strongest audio quality and user interface, but the product's score was hurt by its laborious installation and poor documentation. Data sharing is problematic with VTel's WG500 Beta Release 5.0, which was more impressive in terms of features and functionality, LAN performance and installation. We reviewed VTel's beta version because IP video transport is missing from the version of WG500 that is currently shipping.

Seeing is believing

The most obvious advantage videoconferencing has over conference calling is the ability to see the people on the remote end; so video quality is important.

To measure video quality, we looked at five different criteria:

• Frame rate: maximum amount of full-screen images transmitted per second.

• Image clarity: a factor of the number of pixels defined per image.

• Lip sync: synchronization of voice transmission and lip movement.

• Delay: time it takes to deliver transmitted video and audio.

• Motion compensation: how well a system deals with excessive screen motion.

Intel TeamStation achieved impressive video quality over IP when a call was established between two Intel systems, but the product lost points for image clarity and motion compensation when connected to non-Intel systems. The best IP video quality came from the VTel WG500 beta release, which makes up for some of the WG500's ISDN's shortcomings. With VCon's MediaConnect, we experienced great difficulty establishing a call from or to either of the other systems. When we were able to connect, image quality ranged from poor to non-existent, with no image appearing at the far end.

As for ISDN, Intel's current version of TeamStation supports only low data-rate ISDN calls, but video quality was outstanding at 128K bit/ sec. Intel is planning to release a higher data-rate TeamStation in the fall. Over ISDN, the VTel WG500 was inconsistent in terms of video quality, displaying a significantly different image depending on the system to which we connected. The quality of VCon's MediaConnect over ISDN fell slightly below that of TeamStation at 128K bit/sec, particularly with image clarity. MediaConnect does support 384K bit/sec transmission speeds, at which it is superior to VTel's WG500.

We tested audio under both optimal and not-so-ideal videoconferencing conditions. Of the three systems, we found that MediaConnect projects the cleanest and best audio quality utilizing each algorithm. VTel WG500 finished a close second followed by TeamStation. MediaConnect was the most consistent in each of the environments on both ends of the call. Our biggest complaint with the WG500 is that the audio output was considerably lower than the other two systems, particularly in multipoint scenarios in which we put all three systems side by side in a four-way conference with a PictureTel Concorde. Intel's greatest fault occurred in conference rooms with less than optimal surroundings where the audio would actually fluctuate in strength. We found this to be extremely disruptive.

Cause and effect

While videoconference users would like to see video quality move closer to that of television, they'd also like equipment usability to move closer to that of the telephone. The best user interface enables simple operation while incorporating full-system manageability.

We liked the large, descriptive icons of Intel's TeamStation interface but found access to some features cumbersome. Selecting audio mode or bit rate for an IP call, for example, requires a user to shut down the video application and open a separate program.

The VTel WG500 interface was troubling for some of our novice users, who had trouble finding a toolbar hidden behind a VTel logo on the local video screen and also had difficulty distinguishing some icons. Simple functions such as muting local audio are buried inside the toolbar.

Of the three systems, VCon's MediaConnect has the best interface for both novice and experienced users. On-screen icons and pull-down menus can activate all system functions.

Data sharing prognosis

An intuitive interface becomes more important when you begin to take advantage of built-in collaboration features such as T.120-based data sharing. T.120 enables a virtual whiteboard, file transfer and application sharing. Each of the workgroup systems we tested came preloaded with Microsoft's NetMeeting software to enable data sharing.

Intel's TeamStation offers the best system for data sharing. Tools such as the document server, which allows users to preload documents in preparation for a conference, are useful in streamlining document sharing during a call.

VTel and VCon failed to incorporate NetMeeting seamlessly with the video application. Both systems require a base-level understanding of NetMeeting in order to use the data-sharing capabilities.

While T.120 is supposed to be a standard, we were unable to complete a point-to-point T.120 connection between any of the different vendors' systems. The video connections worked fine, but once we started data sharing, the systems either went berserk or totally locked up. Surprisingly, we were able to collaborate and use all data-sharing features when connected through a Lucent or VideoServer Multipoint Control Unit (MCU).

Interoperability

Each of the systems we reviewed works cleanly in a like-to-like environment. Unfortunately, this is unrealistic in today's video infrastructure. Most companies have invested in products from multiple vendors, and they need to communicate outside of the organization. Interoperability is crucial.

When attempting to connect via IP, the only problem we encountered with TeamStation was that it would not answer a call placed from the VTel WG500. The WG500, however, was able to answer Intel-initiated calls just fine. We had great difficulty establishing a successful H.323 call between VCon's MediaConnect and either the Intel or VTel systems. While the audio generally worked, the video we received was poor.

Conversely, VCon's MediaConnect was a clear winner in ISDN interoperability testing. We had no problems connecting to every system and MCU in our test bed, and MediaConnect maintained consistent video and audio quality levels. One real plus for MediaConnect was its ability to establish a connection through standards negotiation. Even when we specified an incompatible mode for systems on the far end, MediaConnect managed to make a connection.

The VTel WG500 and Intel TeamStation had considerable difficulty connecting to each other via ISDN, with the WG500 experiencing the worst problems. Often, the WG500 would freeze during negotiation and require rebooting.

On the ISDN front, TeamStation also suffered connectivity issues with legacy PictureTel 4000 coder/decoders and the PictureTel Live 200 desktop. Often we were unable to synch up on two-channel ISDN calls. We also experienced problems connecting to a PictureTel M8000 MCU. After we spoke with Intel tech support, we learned that TeamStation will not connect if the H.263 video algorithm is enabled (older versions of PictureTel do not support H.263). After disabling the H.263 option, the systems connected fine. Unfortunately, this is not a trouble-shooting step a novice user would ever consider.

Congestion and quality

Along with interoperability, another concern is how each call impacts the quality of service on a LAN/WAN, and conversely how traffic on the LAN/WAN affects a video call. We found that a single video call does not use up a great deal of bandwidth. The IP equivalent of a six-channel ISDN video call consumes approximately 700K bit/sec. In a 10M bit/sec pipe, this barely causes a ripple. It's when there are several simultaneous calls that video over IP becomes a burden.

In our tests, we were unable to significantly affect the quality of a call by loading our shared LAN with multiple applications. We were able to bog down the LAN so much that none of the endpoints could establish a connection, but once a call was up, video and audio quality remained steady.

Intel's TeamStation performed well with the bits allotted, but the user is limited to two options - 400K or 800K bit/sec. Intel's status screen is helpful but not as detailed as VTel's. We found the VTel WG500 used bandwidth most efficiently. Users can select how much bandwidth they want for a call, from 64K to 768K bit/sec. And with the System Monitor feature, users can identify exactly how efficiently the system is running.

VCon's MediaConnect provides the same bit rate options as the VTel but offers none of the call monitor options found in the other systems.

Features and functionality

All three systems use a wireless keyboard with built-in mouse control. All of the systems also use the same camera, a Sony EVI D30. With the VTel WG500, the camera controls can be managed easily using the mouse. MediaConnect and TeamStation require the use of push button controls to manipulate an on-screen compass.

We liked TeamStation's quick access to active call information, available by clicking the LED bars on the bottom of the screen; but the product could even be better if it included more information such as audio algorithm.

One terrific addition with the beta release of VTel WG500 is the System Monitor. All necessary information on an H.320, H.323 or T.120 call is just a mouse click away. We were impressed with the IP information, which includes a breakdown of data transmitted and received for audio and data. Another nice option is the slide meter, which adjusts video image quality.

VCon's MediaConnect includes some interesting additional features as well. There is a Frame Rate Monitor that shows the current video frame rate being sent and received, and a Conversation Parameters option lists all of the local and remote system video and audio capabilities. VCon also offers an economy mode that saves transmission charges by allowing calls to drop ISDN channels, all the way down to one channel, in the middle of a call.

Implementation

Each of the products claims easy installation, but only two deliver.

The VTel WG500 was the quickest and easiest to install thanks to a competent configuration wizard. It took us about 20 minutes to get the system up and running. We had to refer to the manual a couple of times; luckily, it was easy to follow.

TeamStation was not quite as quick or easy. Intel includes a poster with diagrams of the setup process, but we found the graphics confusing at times. We recommend color coding or labeling cables and inputs.

VCon's MediaConnect was by far the hardest to install. The manuals are hard to follow, and the icons on the back of the monitor are difficult to decipher. For example, it took us several hours to discern how to establish audio. We found the online help to be equally insufficient.

Of the systems we reviewed, Intel TeamStation rated best overall. Our novice users found it the easiest to use, and our veteran users felt it was the most complete videoconferencing system. We also give kudos to the VTel beta release for H.323 quality. Once some of the beta issues are resolved, we believe the VTel WG500 will be the best of the systems for IP conferencing.

RELATED LINKS

Scorecard and NetResults
Key findings and vendor contact info.

Detailed product spec sheets:
Intel TeamStation
MediaConnect
WG500

Nisenson is customer applications manager and former director of network engineering for Frontier Videoconferencing. He can be reached at kyle@ frontiervtc.com. Brian Patrick conducted testing for this review. A former Frontier Videoconferencing operator, Patrick is responsible for the Frontier Evaluation Lab.