Foundry Networks recently improved its ServerIronXL series of load-balancing application switches with new configuration options and twice the application switching performance.The ServerIronXL switch is intended for server farms, where it acts to balance traffic loads among the servers.One new configuration option is a 16-port 10\/100M bit\/sec model with two ports of Gigabit Ethernet over copper, while another sports the 16 copper-based Fast Ethernet ports and two ports of fiber-optic Gigabit Ethernet. Previous ServerIronXL models had 24 ports of Fast Ethernet and options for one or two ports of Gigabit.The switches get their doubled performance from a new operating system. Foundry says the operating system achieves that performance via new algorithms and optimized software.The ServerIronXL switches represent the low end of a larger family of load-balancing switches, a line that scales up to 112 Gigabit Ethernet ports and can support 10-Gigabit Ethernet.The switches can balance loads based on several factors, including application response time, link capacity, or which servers have the lowest number of connections. Foundry also says the switch has a content inspection engine to make switching decisions based on the content of packets. Plus, the switches can check the health of servers; this way, if a server is down, clients can be quickly redirected to available servers.ServerIronXL switches are shipping now, and they start at $9,000 for a 16-port 10\/100M bit\/sec system; adding two Gigabit ports brings the total to $11,000. This compares to a 24-port system, which starts at $15,000.