New traffic optimization and application  acceleration devices combine the features of Layer 4-7 switching along with other technical hooks and tricks aimed at making corporate servers run faster.

New vendors and those that have re-invented themselves over the past few years are promoting appliances that add compression, caching, denial-of-service  attack mitigation and other features designed to make data center servers run more smoothly and securely.

Some observers say these appliances also consolidate, and even outperform, features of products from traditional vendors such as Cisco, F5 Networks, Foundry Networks, Nortel  and Radware.

NetScaler had been a large vendor among ISPs and carriers during the dot-com/telecom bubble, as its Layer 4-7 switches were used to front Web sites and server cages in large hosting centers. When its key markets collapsed, the company refocused on enterprise customers and re-engineered its products to provide more types of services appropriate for corporate data centers.

On the architecture front, NetScaler introduced its 9000 and 9300 series of appliances, which are based on Intel Xeon processors and resemble PCs more than ASCI-based application switches. The devices include a Layer 4-7 packet inspection engine, which can load balance and switch traffic to different servers based on high-level packet data.

Many tricks up its sleeve

With a hard drive and fast Intel-based performance, NetScaler says its boxes can support features such as server caching including static and dynamic database content, and application compression. This helps Web-based applications run more efficiently by streamlining data flows between clients and data centers.

The box can act as a Secure Sockets Layer acceleration appliance, offloading encryption duties from a server and acting as an SSL VPN  termination gateway.

Because its features run in software on the Intel processors, NetScaler says the device can do more than hardware-based Layer 4-7 switches.

Redline Networks is another new vendor in the data center box market. Like NetScaler, Redline sells a device that is based on Intel hardware that provides compression, multi-layer traffic routing, TCP offload and load balancing.

ChartOne, a chart management company in San Jose, started using Redline appliances more than a year ago when its PeopleSoft ERP servers were not performing well. The servers host about 150 clients on the electronic medical documents firm's LAN and across a WAN. They were receiving up to 300,000 transactions a month, says Henry Svenblad, CTO for ChartOne, "and our users, even on the LAN, were very unhappy." On the WAN, it took up to four hours to complete some simple transactions.