To view the Report card.
As in the first roundup, we tested remote-access servers capable of handling at least two T1 (48 channels, 46 for PRI) connections (four T1 were preferred) and able to negotiate PPP and IP/IPX. Access Beyond's AB4400 Remote Access Server, Advanced Computer Communications' Tigris Integrated Access Platform, Ascend Communications' MAX 4048, Bay Networks' Model 5399 Remote Access Concentrator, Cabletron Systems' CSX7000, Gandalf's Xpressway RLAN, General DataComm's SpectraComm RLN and Multi-Tech Systems' CommPlete Communication Server were tested.

With the exception of identifying the best and worst servers, rating the devices was difficult because each vendor offere d a little something different than the others. 3Com's AccessBuilder 5000, with superior performanc e, flexibility and accounting, retains its title from our first round of testing.

Not too far behind, Access Beyond's AB4400 and the Compaq Microcom Access Integrator share second place. The units from Shiva, Cisco and Bay Networks are close on their heels.

Access Beyond AB4400 Remote Access Server
Access Beyond's AB4400 is the top finisher in this roundup, tying for second place overall behind 3Com's AccessBuilder 5000. It offers high throughput, excellent diagnostic tools and easy-to-use management and installation features, and it works extremely well as a medium-sized solution when PPP connectivity is needed for remote users. However, the AB4400 isn't as flexible as the servers from 3Com or Microcom. It lacks LAN-to-LAN routing and Multilink PPP support, and it does not have as high a port density as some of the others.

On the outside, the AB4400 looks like a desktop PC. Inside the box, though, lies a mo dular architecture designed for custom configurations. It maximizes throughput by off-loading processing from the CPU to separate intelligent I/O boards. Routine PPP processing, for example, is handled on the port modules and packets flow through the device without processing from the CPU. This is a remote-access server that can push data from the WAN to the LAN with little degradation. IP and IPX transfer times rivaled those from Bay Networks' unit and--with the exception of ZIP file performance over IPX--blew away the rest of the pack.

Access Beyond's diagnostic tools were second to none, and only the Cisco AS5200 offered a higher level of detail in traces. Using the terminal screen, via telnet or through an RS-232 connection to the console port, you can dig deep into call tracing from Layer 1 up to Layer 3 of the protocol stack. This could be very beneficial for you when you're setting up the AB4400. Additionally, with the AB4400 we wer e able to verify the operation of our test bed from the server sid e by looking at the T1 A/B signaling bits up to the IP negotiations within PPP.

We did have initial problems setting up more than 16 calls connected simultaneously. Access Beyond located a limitation in the AB4400's hash table, which maintains the port IP addresses: It could hold only 16 addresses per Class B subnet. The code was recompiled, allowing for a larger range of addresses, and the connections ran well. Access Beyond states that this will be fixed and will appear in the next release of the code base.

Server installation and management of AB4400 is relatively straightforward. Both the GUI and the terminal interface are well-thought-out, and important functions are placed where they are needed.

To download an Adobe Acrobat .pdf format version of the Remote Access Servers features charts, click here.