Core Features Scale Summit
Extreme Networks Inc.s Summit 48si does an outstanding job of squeezing 48 ports of 10/100M-bps Ethernet, along with a host of features found in the companys core Alpine and Black Diamond switches, into a 1U (1.75-inch) chassis. With advanced security and traffic-shaping features combined with hot-swappable, dual power supplies and good throughput and frame-forwarding rates, it might soon be said that no one ever got fired for buying Extreme.Stacking aside, eWeek Labs tests showed that the Summit 48si, which shipped earlier this month, is an impressive performer and a formidable pack leader in the high-density wiring closet switch arena. Using performance testing gear from Spirent Communications Inc., we found that in most standard tests, the Summit 48si performed at wire speed, even with complex ACL (access control list) features turned on. The "i" in 48si signifies the chip set, which is also used in the Alpine and Black Diamond boxes and is the source of the Summit 48sis advanced traffic-handling features, including QOS (quality-of-service), multicast and security capabilities. IT managers should consider the Summit 48si for the wiring closet because it uses the same operating system as lower-end Summit switches, including the legacy Summit 48 (a now-bulky-looking 2U device), as well as the Alpine and Black Diamond switches. Network technicians, therefore, need training on only one switch operating system to configure and maintain the entire range of Extreme equipment. The Summit 48si that we tested, which has a dual power supply and full Layer 3 capabilitiesincluding advanced routing protocols, server load balancing and Web cache redirectionhas a hefty list price of $10,585. The basic Summit 48si without the dual power supply and Layer 3 upgrade lists for $5,795. This is comparable to Cisco Systems Inc.s Catalyst 3550 24- and 48-port switches. (For eWeek Labs March 11 review of the Catalyst 3550, go to www.eweek.com/links.) Ciscos 48-port device costs $5,795 with the basic software and $7,790 with extended support. Down to the Wire (Speed) We tested each configuration of the Summit 48si with three traffic loads: fixed packet lengths of 64 bytes and 1,518 bytes and one test with random packet lengths. We also used 10 IP addresses per flow so the Address Resolution Protocol table and IP forwarding buffer would get a workout that more closely simulated real life. As we expected, the Summit 48si performed at wire speed in a basic configuration that didnt use the devices QOS parameters or rate-shaping features. We were impressed when the device was able to match this same performance with ACLs turned on. This is notable because ACLs require a more extensive interrogation of the data packet, rather than simply forwarding it to the destination address, to ensure that it is from a permitted source. When we changed the test traffic to random frame sizes, we got interesting performance numbers from the Summit 48si; a Foundry Systems Inc. 4802, a 48-port stackable competitor; and a Cisco Catalyst 3550-24 (which uses the same chip set and software as the Catalyst 3550-48; we were unable to acquire the 48-port version in time for this review and adjusted the tests to accommodate the 3550-24s smaller number of ports). During this round of testing, none of the products performed at wire speed. Because engineers from Cisco and Foundry were not on-site to verify the configuration of their products, we will only say that at 88 percent of wire-speed throughput, the Summit 48si did best. Look for a roundup of 48-port switches in a later issue of eWeek. Finally, as in Extremes core switches, the Summit 48si includes eight hardware queues for segregated traffic handling. Therefore, IT managers will have the ability to apply traffic-throttling techniques starting in the wiring closet, should they ever encounter more than the two or three traffic types (such as data and voice over IP) now found on typical networks. This will offload the heavy processing from the core of the network. This sort of future-proofing is part of what makes Extreme an interesting company to watch for advanced switching trends. Senior Analyst Cameron Sturdevant can be contacted at cameron_sturdevant @ziffdavis.com.
The only factor approaching a shortcoming, which company officials consider a benefit, is that the device is not fully "stackable." This means two or more Summit 48si chassis cannot be cabled together and managed with a single IP address as a single unit. The Summit 48si almost dodges the stacking bullet with a compelling argument: With 48 ports, whats to stack?