Summit48 is list-priced at $7,995 for Layer 2 support. For the pencil pushers, that's less than $167 per port for switched 10/100-Mbps Fast Ethernet. If you subtract the price of the two gigabit ports (about $1,500 each), it comes out to $104 per port--nothing short of phenomenal.

Extreme Networks is working hard to bridge the gap between switched 10-Mbps and switched 100-Mbps networking. Summit48 is a tremendous step in the right direction, and Extreme Networks hasn't forfeited performance in the process. This high-capacity, high-performance box will be challenging the likes of 3Com Corp. and Cisco Systems.

Flowing Down the Summit Summit48 has 48 fixed 10/100BASE-TX interfaces and four GBIC (Gigabit Interface Converter) Gigabit Ethernet modular connectors. Two of these gigabit connections can be active, while the other two are available for standby redundant connections. Because Extreme Networks uses modular GBIC interfaces, you can choose between 1000BASE-LX and 1000BASE-SX or upgrade later.

I tested Summit48's performance using three Netcom Smartbits chassis to generate wire speed Layer 2 traffic on all 50 ports. I used Netcom's Advanced Switch Tests 1.30 to generate traffic in a fully meshed pattern among all ports. Summit48 forwarded Layer 2 traffic between all 50 ports at wire speed without dropping a packet for packet sizes of 64, 128, 512 and 1,518 bytes. Altogether, Summit48 forwarded more than 10.1 million packets per second without errors.

Summit48's multiple queue-based QoS (quality of service) architecture resembles earlier Summit products. In the lab, I used Microsoft Corp.'s NetShow to stream real-time MPEG files through a combination of Summit2 and Summit48 chassis. The Summit2 products provided Layer 3 routing, while Summit48 provided Layer 2 edge connectivity. I started a 1.7-Mbps video stream on each of eight Pentium Pro workstations. The traffic passed from one Summit2 where the server was connected, through a second Summit2 to the Summit48 switch. Three subnet hops created a typical client/server network topology.

We tested it with and without the QoS enabled. Without the QoS enabled, I began to see glitches in the video. The video halted abruptly at rates over 98 percent. With two commands, I enabled QoS on the Summit switches. Summit48 intelligently discarded the packets with lower priority, preserving the video stream's quality even at 100 percent utilization.

Summit48 is highly suitable for mission-critical applications. The switch has an external connector for providing redundant power, and it can support two redundant Gigabit Ethernet uplinks. It also can use its two active gigabit links to perform load-balancing. If one of these links fails, the switch continues to function with a single link, adding another degree of resiliency.

Joel Conover can be reached at jconover@nwc.com.