Routers/Switches /

Port pricing doesn't tell the entire story

By CHARLES BRUNO
Network World, 05/08/00

Ask switch makers for the price/performance of a Gigabit Ethernet or a Fast Ethernet switch, and chances are they'll spit back an attractive cost per port that doesn't really tell you the whole price/performance tale.

Of the Fast Ethernet switches tested since the inception of the SwitchMetric program, Nortel Networks' BayStack 70-16T and D-Link's DES-3225G, both unmanaged switches, posted the lowest per-port cost among devices tested in the SwitchMetric tests at $62 per port.

However, such a number doesn't begin to convey the actual impact the switch has on delivering service because it doesn't factor in performance. Compare those per-port prices to the BayStack 70-16T's $633 cost/gigabit rate and DES-3225G's $663 cost/gigabit rate and you begin to understand the true cost of computing each product.

The 10-to-1 cost differential ratio between the per-port pricing and cost/gigabit pricing holds true for full-functional Fast Ethernet switches we tested as well. If we went solely on per-port pricing, Intel's NetStructure 460T, with a $66 per-port price, would be the hands-down leader among Fast Ethernet switches tested. But with a cost/gigabit of $1,053, the NetStructure 460T ranks about sixth among Fast Ethernet switches tested in terms of cost/gigabit performance.

Most Fast Ethernet switches tested offer per-port prices between $91 and $99, but the SwitchMetric average cost per gigabit of throughput was $1,468. That shows the disparity between the SwitchMetric cost/gigabit, which conveys the cost associated with a switch's throughput and the Fast Ethernet per-port prices. It does not factor in performance, but simply looks at the number of ports offered.

Nortel's BayStack 350-24T, the cost/gigabit leader among managed Fast Ethernet switches tested at $927, posted a per-port price of $91.

What's interesting here is that Hewlett-Packard posted a lower per-port cost for its ProCurve Switch 4000M than Nortel's BayStack 350-24T, yet the Nortel switch is a better buy at $927 cost/gigabit vs. $956 for the HP device.

"It just goes to show that the per-port price does not indicate the actual performance of the switch," says Greg Kilmartin, an engineer with The Tolly Group who oversaw the SwitchMetric testing. "It's better to have a metric that looks at cost in relation to the performance of the switch."

In the Gigabit Ethernet market, the spread between per-port prices and cost/gigabit was much less dramatic than the Fast Ethernet side. The numbers are more in line with each other in the Gigabit Ethernet switch market because generally there are fewer Gigabit Ethernet ports on every switch. The Fast Ethernet feeder switches that use a greater number of ports (usually 32 or 64) carry a lower per-port cost.

What is interesting is to look at the relative cost of Fast Ethernet per-port cost vs. Gigabit Ethernet per-port cost and the corresponding SwitchMetric cost/gigabit ratings. If you look at the top six Fast Ethernet switches, excluding the two unmanaged devices, you have an average of about $94 to $95 per port and a cost/gigabit throughput of close to $1,000. On the Gigabit Ethernet side, the average cost/gigabit throughput of the top four chassis switches is about $1,130, while the per-port price is $1,114.

So while you pay slightly more on a cost/gigabit throughput basis for the Gigabit Ethernet switches, you're getting a full gigabit per port vs. just 100 megabits of throughput per port with the Fast Ethernet switches. Although on a cost/gigabit basis, the Fast Ethernet switches are just $130 less than the Gigabit Ethernet cost/gigabit throughput prices. This comparison shows that the Gigabit Ethernet switches are the better buy.

Of the SwitchMetric participants tested at Layer 2, Foundry's FastIron II Plus GC emerged as the per-port leader ($925 per port) and also the cost/gigabit leader at $938. NBase-Xyplex's OptiSwitch 800F, the cost/gigabit leader among chassis-based switches that support fiber-optic connections, offered a per-port price of $1,044 vs. a cost/gigabit price of $1,058.