Expand's experiences shows in its Accelerator devices

6910 and 6940 products are put through their paces.

Expand, in the WAN-optimization market for eight years, has improved its products relentlessly. The Accelerator 6910 and 6940 proved in testing to be effective WAN-traffic front-end processors.

Expand has been in the WAN-optimization market for eight years, longer than most vendors. The company has refined and improved its products relentlessly. The Accelerator 6910 and Accelerator 6940 devices Expand submitted for testing at our Alabama network lab were particularly effective WAN-traffic front-end processors. They were reliable, scalable and easy to configure.

Clear Choice Roundup logo

Expand Networks' considerable experience in reducing and prioritizing WAN traffic showed in the Accelerator 6910 and 6940 appliances. In our opinion, the 6910 is appropriate for smaller, regional data centers, while the 6940 is best suited for a central site that can handle aggregate traffic from several 6910 devices, for example. The 6910 appliance can easily shoulder a workload of 10Mbps and as many as 50 remote sites, while the higher-performing 6940 has a capacity of as much as 20Mbps and 200 remote sites.

Working together, the 6910 and 6940 units achieved an average bandwidth-increase factor of 6.2. They fared well with Citrix, Oracle and VoIP traffic, accelerating the related traffic by an average bandwidth-increase factor of 11.0. Impressively, they attained a blistering average bandwidth-increase factor of 22.6 for Web, e-mail (Exchange and Notes), FTP and file-sharing (Network File System and Common Internet File System) traffic.

Our analysis showed the units definitely would let us tell our telco to dial back a full T-1 link to a fractional 512Kbps link yet still enjoy the same throughput. This would typically save about $1,000 per month, per link.

Traffic shaping

The units we tested operated at or near wire speeds, introducing virtually no latency. The 6910's and 6940's traffic-shaping feature offers high, medium and low inbound and outbound congestion control. We prioritized Oracle, Web services and file-sharing traffic while relegating e-mail and HTTP traffic to the back of the queue and found that during busy times, our business-critical traffic zoomed through the links ahead of less-important data.


Expand Networks

Price:Model 6910 starts at $9,000; Model 6940 starts at $13,000.
Pros:Scalable; near zero latency operation.
Con:Needs clearer documentation.
The breakdown
Performance 30%5Scoring Key: 5: Exceptional4: Very good3: Average2: Below average1: Subpar or not available
Protocol support 20%4

Ease of use 20%

Scalability 20%4
Documentation/installation 10%3

Furthermore, both units have a transparency mode for MPLS traffic that lets a telco or service provider identify MPLS packets within a compressed, optimized datastream and give them higher priority.

Both units recognized and accelerated the HTTP, DNS, FTP and TCP protocols by providing anticipatory acknowledgments and larger TCP windows. The devices also contain application-specific discovery and acceleration technologies for more than 100 predefined data flows, including Citrix and VoIP. The devices are Remote Monitoring/RMON2-capable, and both integrate well with Cisco's NetFlow.

Accelerator 6910

The 6910 includes 2GB of RAM, and the 6940 has 4GB. Both devices use an especially quick 500GB hard drive. The 2U rack-mounted devices include dual, hot-swappable, auto-sensing power supplies. They have two 10/100 RJ-45 ports, along with a separate RJ-45 port for out-of-band management (the 6940 has a Gigabit Ethernet port for out-of-band management).

Both units have a serial RS-232 console port and USB port, and comply with RFC-2281 (Hot Standby Router Protocol) and RFC-2338 (Virtual Router Redundancy Protocol) failover standards. When we interrupted power to the units, they switched to an internal pass-through mode. The network traffic reverted to an uncompressed, non-prioritized state but otherwise suffered no ill effects.

We configured the 6910 and 6940 primarily through browser-based Web pages, which use SSL for privacy. The units' internal Web servers have an intuitive, easy-to-navigate interface.

Configuration was as simple as assigning the units an IP address and choosing such options as MPLS transparency. Web pages containing reports showed traffic statistics and device status information.

Accelerator 6940

Once you configure the 6910 or 6940, you probably won't need to pay much attention to them.

The documentation from Expand Networks was comprehensive, but its explanations and networking references could be clearer. Installing the appliances was easy and straightforward.

We heartily recommend Expand's WAN optimization tools if you want to boost performance and significantly reduce your telco data line charges in the process.

Learn more about this topic

Expand integrates WAN optimization features into one platform


Expand Networks adds WAFS support


Expand overhauls compression line


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