Web Site Stress Tests to Go

Avalanche 220 puts small networks through their paces.

Avalanche 220

Spirents Avalanche 220 is a compact appliance for field engineers who need a powerful Web-stressing device at hand to assess network performance of small-to-midsize sites. The 220 has a reasonable upfront cost and doesnt require much training, thanks to its intuitive Web-based management interfaces.
















  • PRO: Powerful real-world Web traffic generation in a compact form factor; easy to set up.
  • CON: Limited scalability.

• Ixias ELA

The latest Avalanche 220 capacity assessment appliance from Spirent Communications Inc. packs plenty of Web-stressing horsepower in a compact form factor, while keeping things simple.

The Avalanche 220 is a stripped-down, portable version of Spirents Avalanche 2200 Web-stressing appliance. The 220 is about the size of a small router, weighs less than 4 pounds and stands less than 1U (1.75 inches) high. However, the 220s small size doesnt mean it cant put out big numbers: The compact appliance can generate as many as 60,000 concurrent connections and 10,000 requests per second using HTTP 1.1 with persistence enabled.

Those are impressive numbers, considering that the larger 2200s performance starts at 10,000 requests per second. However, the 2200 can scale to more than 50,000 requests per second and includes some features that arent found in the 220, including protection from distributed-denial-of-service attacks, virtual LAN tagging and IP fragmentation support.

Nevertheless, the 220 has enough power to accurately stress test the performance of most small and midsize Web sites, while being small enough to travel with the field engineer.

The 220 is available now for $19,500 and runs WebAvalanche Version 5.0, the same software as the 2200.

In our tests, we quickly set up the 220 from a laptop using Microsoft Corp.s Internet Explorer. (Any Web browser will work.) The 220 uses the same management interface as the 2200 appliance, since both run the same software.

The feature that sets the 220 apart from its competitor, Ixias ELA (Enterprise Load Appliance), is its ability to create user profiles to simulate close-to-real-world traffic. For example, using the 220, we could create conditions such as browser emulations, Secure Sockets Layer parameters, URL traffic patterns, packet loss and link-speed limits.

Because it runs Version 5.0 of the Avalanche software stack, the 220 has most of the features found in the 2200, including support for popular streaming media protocols.

Large enterprise sites can use the 2200 for realistic assessment of their infrastructure while using the smaller 220 for branch offices. In addition, ISPs can use the 220 to fulfill service calls in the field by testing new rollouts or to meet customer service-level agreements.

In terms of competition, Ixia is the only other vendor we know of that makes a portable network traffic load generator. Companies looking for a portable appliance should look at Ixias ELA. However, the ELA—a portable computer with modular slots for attaching different network interfaces (from Fast Ethernet to Gigabit Ethernet)—is bulkier than the 220.

As a self-contained appliance, the 220 can scale only with software upgrades. This could limit its usefulness as networks improve in overall performance. The ELA is a more scalable and flexible system, but the 220 has the edge in ease of use and real-world testing schemes.

Technical Analyst Francis Chu can be reached at francis_chu@ziffdavis.com.