Routers/Switches /

Switching shindig

Extreme to debut load-balancing, cache re- direction technologies.

By Jim Duffy
Network World, 05/08/00

LAS VEGAS - Extreme Networks this week will unveil software that will give customers more bang for the switching buck by adding cache redirection and load balancing.

The new switch software, making its debut at NetWorld+Interop 2000, enables Extreme's backbone, departmental and metropolitan-area switches to cache Web addresses and balance traffic loads between servers. The software also adds a key Internet routing protocol and traffic rate shaping capabilities to the switches.

With the new features, Extreme is actually playing catch-up to some of its competitors. Foundry Networks says it has been shipping similar capabilities for up to 18 months. And Cisco, the leading supplier of Internet routers, has been offering similar services for years.

The software, called ExtremeWare 6.1, is designed to run on Extreme's Summit and BlackDiamond workgroup and backbone switches, and recently announced Alpine switches for metropolitan-area networks that incorporate the company's latest-generation "Inferno" silicon. The company could have added these functions to its earlier "Summit" CPU-based switches, but performance would have been compromised, Extreme officials say.

The Web cache redirection capability will steer Layer 3 or Layer 4 traffic streams - not just Web traffic - to cache devices, Extreme says. Traffic with common destinations will be directed to the same cache device or devices.

Caching increases network efficiency by storing frequently accessed data closer to the end user.

For server load balancing, ExtremeWare 6.1 includes source code from partner company F5's Big-IP load-balancing technology. Extreme says its software can support wire-speed performance for a virtually unlimited number of sessions, and that new sessions can be added at wire speed.

ExtremeWare 6.1 also supports F5's 3-DNS global load-balancing technology, which uses local load-balancing data to gather metrics for global balancing decisions.

The software also supports Border Gateway Protocol 4 (BGP4), which will appeal to service providers offering Internet and other public and virtual private IP-based services. BGP4 is an interdomain protocol used on the Internet. It exchanges route information between BGP4 systems and is used by service providers to interconnect their separate networks.

Meanwhile, Extreme says the bidirectional rate shaping feature is vital for quality of service. The technology allows users to control traffic to and from a virtual LAN by differentiating traffic flows, and then defining maximum and minimum bandwidth for each flow on a per-port or per-queue basis.

IP flows are identified via Layer 1 through Layer 4 information and Differentiated Service bits. Diff-Serv information can be overwritten if data comes from an "untrusted" source, Extreme says.

In addition, 802.1p priority bits can be mapped to the rate shaping function, the company says.

The software also supports Random Early Detection for congestion control.

ExtremeWare is preinstalled on every Summit, BlackDiamond and Alpine switch. Version 6.1 is available now at no charge for customers with support contracts.