• United States
Neal Weinberg
Contributing writer, Foundry

Expand Accelerator 4000 and 4800

Aug 28, 20032 mins
Enterprise Applications

* The Reviewmeister continues to check out dedicated network compression devices

Expand’s Accelerator 4000 and 4800 models are similar products for different architectures. The Accelerator 4000 is a WAN-based product that connects directly to a router’s serial ports. The Accelerator 4800 is a LAN-based product that connects to the network through a 10/100 Base-T Ethernet interface.

Both provide high-bandwidth dataflow (up to 6M bit/sec in the 4800 and up to 2M bit/sec in the 4000 model) and strong performance, but with a cost to be paid in terms of setup and administration complexity.

Expand refers to its performance boost as “acceleration” rather than simple compression. The results obtained are based on traffic stream compression, header compression, data caching and error recovery.

While Expand’s systems produced good results when deployed with default compression, performance improved considerably after experimentation with various error-correction features. For packet aggregation to have a significant effect, we had to adjust timing values.

The default performance of the unit was quite good, especially in testing with voice-over-IP traffic. Typical compression of VoIP traffic using devices in this review resulted in a 20% to 25% reduction rate – Expand’s WAN accelerators compressed that traffic by 5% to 10% more. The TCP and UDP traffic tests showed good levels of compression. Expand also did well with the QoS test, performing on par with the other systems tested.

Expand’s Accelerators provide encryption and compression to traffic, act as authentication servers, and support numerous router- and application-specific protocols. They do not, however, support the basic security functionality of Secure Shell (SSH), a significant lack in a system that provides other security features.

The administration command-line interface will be familiar to anyone who knows Cisco’s IOS, and the Web-based GUI provides plenty of performance graphs, charts and tables, although the GUI was neither as polished nor as easy to navigate as those found on other systems tested.

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