To drive the 5399s, you need a Windows NT or a Unix server that can host boot images, configuration files and other tools necessary for the proper boot-up and management of the server. When booting, the 5399s look to the 5000 management module and obtain their IP address and the n etwork address of the configuration server. The 5399 Remote Access Concentrator then contacts the configuration server and obtains other details. The information is stored as text files, which are created by hand or with the Q2Config management GUI. In the absence of a configuration server, the 5399 configures itself to factory defaults. We encountered a few problems when using the Q2Config GUI, such as an inability to configure the T1 ports. Bay Networks is aware of these problems and says it will address them in a future release.

In terms of performance, Bay Networks' server kept pace with the top winners, largely because of its multiprocessor architecture. Each card is populated with three Intel 486 DX2/33 processors: one main processor and two processors for I/O. The I/O processors have 4 MB of RAM--for both the code and memory buffering. The main CPU has 8 MB of RAM. These three cards provide more than adequate CPU power and memory to handle packet processing for the modems. In addition, performance is enhanced by two daughterboards that perform data compression, relieving other processors from that task.

Prepared for Failure Bay designed the 5399 for reliability, but all hardware eventually fails. To prepare for the inevitable, the 5399's modems are located on daughterboards (24 to a board). If a modem board needs to be replaced, simply pull the 5399 out of the rack and replace the daughterboard. New cards are automatically configured at boot time.

Since it gets its configuration information from a single location, configuring the 5399 was a snap. We wanted both of our 5399 units configured identically, so we made one configuration file and pointed the two 5399s at it. We were able to make configuration changes on the fly--but only to one 5399 at a time. Changes made after the unit is booted won't take hold until the next reboot. However, using the Q2Config utility, you can make changes to the server and the configuration file simultaneously. Port-level changes can be made on the fly.

General DataComm SpectraComm RLN
The SpectraComm RLN remote-access server is the result of a pairing between General DataComm and Attachmate Corp.; Attachmate's Remote LAN Node software has been redesigned to work seamlessly with General DataComm's hardware. We found the bundled management and accounting packages useful for organizations that don't have any accounting servers. The software provides an extensive set of utilities to manage both the server and your user base. But the SpectraComm hardware supports only 64 modems, making it less scalable than Bay's Model 5399, and more difficult to configure than Access Beyond's AB4400 or the 5399. And even though its performance was acceptable, the SpectraComm RLN still lagged the leaders.

The SpectraComm RLN runs on a Dell Computer Corp. OptiPlex GM5122 system and uses modem racks and a multiport serial adapter board from Equinox for asynchronous connectivity. The server manages call control, routing and server functionality while the Equinox modem racks handle data I/O. Although the SpectraComm RLN can accommodate a maximum of 64 modems, two Equinox racks (supporting a single T1 each) can be chained together for 48 modems. The remaining 16 modems, eight in each rack, can be attached to a multiport asynchronous board in the server.

Running on DOS, the SpectraComm server requires a sparse 8 MB of RAM, though the unit we tested shipped with 16 MB.

On the plus side, we particularly liked the range of authentication methods SpectraComm supports. It also allows seamless management of user authentication and profiles across multiple servers. Using a hierarchical approach, we were able to add servers to our domains and distribute management functions and authentication profiles from one central location.

Getting the Bugs Out General DataComm's unit also has some comprehensive debugging and tracing capabilities, though not as detailed as the AB4400's. For example, while debugging connectivity problems, we were able to track call setup and disconn ect. The RLN manager offers very detailed reporting for connection start and stop times, user names and the amount of data sent over the link. The log file can be viewed within the management GUI, or it can be imported into a spreadsheet for customized reports. While reviewing the reports, we were able to tell when calls ended prematurely (an event that occurs with all remote-access servers), how long they were up and who was logged in.

Configuring and managing the SpectraComm server is straightforward and flexible. Using a keyboard and monitor attached to the server, you can quickly move through important screens during the initial installation. You must manually define each port as a specific modem type--a task that in practice isn't as tedious as it sounds. You can move through each port with the cursor in the same relative position. Having a default configuration or allowing mode m grouping would make the configuration easier.