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Server-Based MCUs
VideoServer Encounter NetServer
The VideoServer Encounter NetServer eight-port system we tested radiates an aura of good genes and muscle. Although its gatekeeper (GK) and multipoint conference server (MCS) systems can be managed via browser from anywhere on the network, conference operators will find a look and feel reminiscent of the software in VideoServer's successful H.320 bridge product.

The Encounter MCS doesn't support continuous presence, but its video-follows-voice switching is natural, consistent and effective. Perhaps the strongest feature that sets Encounter apart from its competition

is mixed-mode conferencing. Endpoints using G.711, G.723 or G.728 audio can interoperate within the same conference. Using Encounter NetGate software and an optional T1/PRI interface, you can bring ISDN-connected H.320 systems and voice-only phone calls into the conference as well. This can be very useful to operators who need to pull in a participant in transit.

It's obvious that new Encounter products have benefited from VideoServer's work with Intel to sort out compatibility issues with ProShares and TeamStations, and with Cisco Systems to understand LAN/WAN distribution issues, including multicast support.

For example, the built-in Encounter Gatekeeper has a zone addressing plan that allows prepending (e.g., 1-800-555-) and/or suffixing (e.g., @domain.com) so you can place local connections using only a four-digit phone number, or alphanumeric terminal ID; you can dial an endpoint owner's full phone number/terminal ID from a listing in the enterprise's main directory. The gatekeeper manager can resolve destination addresses by multicasting to other gatekeepers and checking alias name lookups, or performing Internet locater service (ILS) lookups for fully qualified domain names.

In tests with Encounter's built-in gatekeeper, we found that Intel ProShare 500, Zydacron Z350 and NetMeeting 3.01 are registered appropriately. When a PS 500 endpoint calls another ProShare, the session sets up with G.723 audio and H.261 CIF in both directions. However, a PS 500 calling a Z350 sets up with G.711 audio in both directions. This also happens when these endpoints make calls and there's no gatekeeper in the picture. The point is that the Encounter GK appears not to get in the way of endpoint capabilities exchanges.

We also confirmed that the Encounter MCS can work with an external third-party gatekeeper--in this case, the one built into RadVision's MCU-323. But we observed the Encounter MCS registering only one of its available conferences with RADVision. It's not clear which side was at fault. This may be an example of the fine-tuning the manufacturers will investigate at this fall's "interop" sessions.

Encounter NetServer, starts at $24,990 for eight user licenses, VideoServer, (800) 466-7845, (781) 229-2000; fax (781) 505-2101. www.videoserver.com