Videoconferencing Picture Clears Up

FRAMINGHAM (03/13/2000) - Despite the growing list of benefits for end users, real-time videoconferencing still poses more issues than answers in the minds of network managers. Companies that purchased first- and even second- generation systems paid dearly and were rewarded with less-than-TV-quality video, complex user interfaces, low reliability and limited centralized network management capabilities.

But the good news is that the third- and fourth-generation H.320/H.323 videoconferencing systems we tested - all eight of which sell for $12,000 or less - address all these past usability issues. The systems offer improved video quality, provide standardized collaboration tools, and some manufacturers have added centralized management tools.

We divided the products into two categories: conferencing appliance products and collaborative computing systems. Conferencing appliances are typically composed of a set-top box coupled with a National Television Standard Code (NTSC) display for presentation and small group virtual meetings. Polycom Inc.'s ViewStation MP, VCON's MediaConnect 6000 (MC6000) and Sony Corp.'s Contact fall into this category.

Then there are PC-based products that emphasize collaboration, with remote collaborators appearing in one window on a portion of a VGA or RGB screen and the collaborative tools filling the remainder of the screen. The products in this category are VCON's MediaConnect 8000 (MC8000), VTEL's Galaxy 725, Intel's TeamStation, PictureTel's P550 and VTEL's SmartStation.

Polycom's ViewStation MP provided the best "talking head" experience, topping the field in ease of installation, configuration and use, and thereby earning the Network World World Class Award. VCON's MC8000 topped the collaborative computing category by virtue of its highquality PC components.

The most notable objection to using videoconferencing as a substitute for face-to-face meetings is lack of business-quality video and audio. Regardless of the user's level of expertise, jerky video, clipped audio, poor synchronization between lips and words, and echo from either side are serious drawbacks. We are happy to report that video quality has risen dramatically in the past 12 to 18 months.

One of the biggest factors influencing audio and video clarity is the input device. With the exception of two low-end systems, VTEL's SmartStation and PictureTel's P550, all the systems we tested have standardized on the Sony EVI D30/31 video camera. With high-quality optics and built-in pan, tilt and zoom capabilities, this camera yields an image output equivalent to a consumer camcorder.

Manufacturers' microphones varied widely. Polycom's was the best overall. VCON, VTEL and PictureTel all bundled Audio Technica unidirectional boundary microphones with their systems. These devices, commonly referred to as PZM microphones, match Polycom's standard in some areas. However, Polycom's superior echo cancellation and integrated mute button give it the overall edge in our tests.

VTEL's Galaxy 725 set the standard for audio integration with its three-input balanced XLR mixer. XLR is the acronym used for a Cannon 3 Pin connector. Other manufacturers supported single TA3 or 3.5mm (1/8-inch) connectors, which are more susceptible to interference and hum.

Using VHS-quality NTSC playback at 29.97 frame/sec as our benchmark, we found that all products provided acceptable business-quality video. For our tests we limited motion on the screen to moving lips, facial expressions and subtle body language, and the video frame rate exceeded 20 frame/sec at 256K-bps or higher.

Video produced by the two industry standard algorithms (H.263 or H.261) provides equivalent quality at 384K-bps, and the price/performance "sweet spot" for video and audio quality remains at 384K-bps over ISDN. Video quality at 384K-bps on an IP network was perceptibly lower than the equivalent data rate on ISDN, in terms of clarity and in lip synchronization with audio. This is due in part to IP's overhead requirements because headers are added to packets for transmission.

The codecs - PC add-on boards for video encoding and decoding - for the products we tested differed substantially along three video-quality axes: color, image clarity and refresh rate. In these three qualities, Polycom's ViewStation MP is unsurpassed. It failed to earn a 10 on our scorecard only because of image degradation on slightly loaded non-quality-of-service (QoS) IP networks.

Intel's TeamStation 5.0 and VCON's MC8000 also fared well in our video and audio quality tests. TeamStation's incoming video clarity was consistently well above average, although the spectral properties failed to match the skin tone of the subject, and video at the receiving end (if not used in a TeamStation-to-TeamStation configuration) was only of average quality.

The MC8000's video quality was above average when shown at its optimized quarter-screen size. However, on an NTSC video monitor, the quality deteriorated. We scored the quality high with the understanding that the MC8000's video is intended to support collaborative activities and is not to be used as a talking head small group system. In addition, the MC8000's video quality was arguably more tolerant of network congestion in an IP environment than other systems in the same conditions.

While the five remaining systems were adequate for talking head applications, they exhibited significant differences in autoadjusting echo cancellation for audio feedback, image clarity, lip synchronization and motion-induced artifacts.

PictureTel's P550 and VTEL's SmartStation received low grades in this category because they are based on codecs that are now 2 years old.

Interfacing with faces

While video and audio quality are important, you also need an inviting, predictable and responsive user interface. Polycom's ViewStation MP, whose on-screen interface and handheld remote control features look more like a video game than a complex telecommunications system, sets the industry standard.

While nothing matches this 2-year-old interface, other manufacturers have overhauled their old calling interfaces with generally good results.

VTEL's Galaxy 725 handheld remote control is very attractive. The black and steel-blue unit offers a thumb-friendly joy stick for controlling camera movements and displaying on-screen menus. On-screen images for navigation and system control are easy to read, though not always intuitively organized, considering it overlays higher-resolution VGA output on a NTSC monitor.

Sony's handheld baton is also high-quality, but the unit's interface is less than intuitive. Users may be intimidated by its many rows of small buttons and confusing commands. Sony's on-screen text menu is clear, but some common settings (as in selecting bonding or switching between ISDN and IP) typically require a reference to the manual.

Text and data entry is awkward on any handheld remote, so the Galaxy 725, Intel's TeamStation and both VCON units include infrared keyboard and mouse support. While these units provide wireless connectivity, we found the slower-than-normal response times exasperating.

The MC8000's complex, multi- window interface is best-suited for advanced users, but its icon-rich interface does make the system fully international.

By contrast, the TeamStation user interface is simple, intuitive and a significant improvement on past iterations. However, it doesn't let users access settings and adjust configurations to suit a particular application.

This increases system reliability, but it goes too far in some respects, as TeamStation eliminates basic user controls such as adding a number to the speed-dial directory.

Trailing the pack in this category is PictureTel's P550. Its user interface is reminiscent of the Windows 3.1 era, requiring separate menus to be closed and new ones opened for different functions. This is especially unfortunate given that it runs on a Windows NT platform, which is capable of many advanced capabilities.

Special features galore

End points must support a range of call configurations. Of the presentation systems, Polycom's ViewStation MP and Sony's Contact support multipoint conferences over ISDN as an option, with each point connected at 128K-bps - a useful feature when connecting satellite offices. The ViewStation also includes a two-port Ethernet interface - one for connecting the ViewStation to the corporate LAN or remote IP-based end points, the other to interface with a PC in the same room. Contact's serial interface lets you connect a computer to the system for presentation support.

We liked Contact's modular architecture. The base unit is upgradable through an expansion slot that we used to enable full 384K-bps H.320 support and, alternatively, to support IP-based conferencing. Contact's base also allows you to easily detach the EVI D30 camera head, lets you rack-mount the codec and permits potential upgrades to the video device.

VCON's MC6000 and MC8000, ViewStation and VTEL's Galaxy 725 support dual-camera inputs and dual-monitor configurations. We applaud that all the systems have the ability to take high-quality snapshots using either near- or far-end cameras and send the images to remote participants during the call.

Of the collaborative computing systems, the MC8000 stood out in the features department. The $10,995 bundle includes all necessary hardware and software for audio- and video-over-IP call control and an NT machine for enhanced collaboration. The MC8000 provides two unique features - bundled copies of Microsoft Office 2000 and Packet Assist network software for QoS and bandwidth management on IP networks. Packet Assist utilities include an automated adaptive bandwidth function that adjusts a session's video data rate in the event of network congestion.

For an additional $250 per seat, VCON provides software called Interactive Multicast. We did not test this feature, but VCON claims that with Interactive Multicast, an end point can be the source or recipient of an IP Multicast stream.

With such a range of features among the products tested, we wouldn't have been surprised to find call placement interoperability issues. We were pleasantly surprised at the level of interoperability among systems using H.320 protocol signaling for call establishment and management over ISDN, and even more surprised to discover H.323 interoperability over IP. With only a few minor exceptions, we were able to place and receive calls to and from all systems in the test bed.

Administration and system management

Due to their complexity, these products ship with some remote administration and system management tools. But all of these tools are certainly not created equal.

Polycom's ViewStation MP and VTEL's Galaxy 725 received exceptionally high system-management scores. The ViewStation is manageable across ISDN and IP, meaning that software upgrades, changes in settings or changes in address book entries are easily pushed from an administrator's system to any ViewStation over IP or ISDN. Polycom's Global Management System - a separate application available from the manufacturer - provides real-time activity monitoring, error reporting and remote call setup and tear-down of multiple ViewStations. With the Global Address module you can use a centralized address book of up to 50,000 addresses, providing up-to-date content for all end points.

VTEL's SmartVideoNet Manager, now in its second generation, uses SNMP to communicate requests, translate events, and record actions and errors on a centralized network management server. The console application supports real-time activity monitoring, error reporting and diagnostics, remote call setup and tear-down, and address book management for any VTEL SmartStation or Galaxy system in which the client-side SmartVideoNet agent is loaded.

Intel's TeamStation management console is a separate application that can only be run when the TeamStation user interface is closed. This discourages the average user from tampering with system settings. Should there be problems with disconnected cables or malfunctioning hardware, the real-time self-diagnostics help users troubleshoot most problems before calling a system administrator.

VCON's MC6000 and MC8000 have basic support of SNMP management on an IP network. Sony's Contact and PictureTel's P550 don't support remote management at all.

Most of the systems were generally stable. However, the TeamStation suffered from repeated application-level errors after receiving H.323 calls from unlike systems. We also found that as we connected and disconnected ISDN lines for testing, Sony's Contact required rebooting to "rediscover" its network connection. Conversely, we liked the fact that with the exception of removing the first Basic Rate Interface ISDN line, Polycom's ViewStation MP can continue to receive calls on IP without having all the lines for which it was originally configured physically connected to the unit.

We had only minor problems with the installation and setup of products as a whole. A novice could expect to have any of these systems up and running in less than 30 minutes. We gave the MC6000 the lowest score because its dual-monitor setup requirement was the least intuitive.

As far as documentation, VTEL's Galaxy 725 and VCON's MC 8000 set the bar for manuals that are highly visual, clearly written and exceptionally produced.

After our extensive testing, we were encouraged to see substantial progress in the past year in the areas of user interface design and IP video interoperability. For environments in which PC applications will never be used or shared, we believe set-top boxes are significantly more attractive. Whether you envision multimedia conferencing or are strictly planning to have talking heads on the screen, any introduction of video on an IP network should begin with a comprehensive review of all local- and wide-area infrastructure. We feel confident that any of the top four products rated here could satisfy your group videoconferencing needs for at least the next 18 months as enterprise data networks improve to support real-time applications.

Perey is president of Perey Research & Consulting, a Placerville, Calif., firm providing business development and market research services to multimedia network and business communication technology providers. She can be reached at cperey@perey.com.

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