Extreme Configuration

By Dave Greenfield  |  Posted 2008-08-18 Print this article Print

As a baseline, we selected extreme's BlackDiamond 8800. The Extreme configuration was less complicated because its range of options is narrower than Cisco's.

All configurations led with a pair of redundant 8806s in the core. The six-slot chassis were configured with dual 8800 Management Switch Modules for redundancy. There were 48 1000BaseX ports for downstream connectivity providing redundancy to all chassis. There were also four 10GBaseX ports providing for redundant connections to each hub. All connectors were included. Power was provided by three 700W/1,200W power supplies.

Extreme uses the BlackDiamond 8810 in the wiring closet. Each 8810 was equipped with the 8800 Management Switch Module and eight 1G-bps ports (1000BaseX) for upstream connectivity. Downstream, Extreme equipped the 8810 with 336 10/100/1000BaseT POE ports for a total of 4,032 10/100/1000 POE ports across 12 wiring closets. Power was provided by three 700W/1,200W power supplies.

Migration Costs

Overall, the price of the Cisco solution compared favorably with that of the Extreme solution, assuming IT had the foresight to deploy 10/100/1000 POE to the desktop at the outset with a Supervisor 32 module. Cisco's configuration ($109,000 overall; $325 per port) would have run 11 percent more than Extreme's configuration ($112,930 overall, $294 per port). Because the 6509-E options are so vast, however, there's also room for error. Had IT, for example, not deployed 1000BaseT POE to the desktop-but instead had chosen a mixed 10/100/1,000M-bps environment-costs would have been 14 percent higher.

Such a possibility didn't exist for Extreme because the company only offered 10/100/1000 POE modules. Having said that, organizations that purchased the 8810 in early 2006 would likely have chosen Extreme's G48P modules, which ran $7,000 more than the non-line-rate module introduced in August of that year.

The second Cisco configuration option in 2006 was the Supervisor 2, which was introduced in the fall of that year.

Companies that chose the Supervisor 2 would likely have done so at least in part to take advantage of its 256G-bps bus. In our scenario, the upshot would have been a $2.1 million overall expenditure in 2006, mainly because of the more expensive interface modules.

By the end of 2006, the Supervisor 2 would have been at end of life. A company that had chosen the Supervisor 2 would have had to migrate to a new switching matrix, most likely the Supervisor 720, in year three. The result would have been an additional $878,282 charge.

Wireless Ready?

The 6509-E's reliance on a 32-gig backplane means there's an average of 3.5G bps per slot, or just 72M bps per 1000BaseT port. Even if one assumes that there's closer to 4.5G bps per slot, then that still leaves only 104M bps per 1000BaseT port. If 802.11n rollouts mirror current wireless deployments, oversubscription numbers like those will likely not pose initial problems.

"I typically see an access point deployed every 75 feet," said Network Authority's Fistler. "In a hospital, we might see 20 to 30 of the 200 to 300 ports dedicated per closet for an access point."

Put another way, that translates into a little more than a gigabyte of traffic per slot, with another 2.5 to 3.5 gigabytes for the remaining 44 ports. In dense 802.11n environments-or in health care, graphic design or CAD/CAM environments-IT may want to carefully assess the capacity of its 6509-E.

Presumably, as organizations deploy 802.11n devices, Cisco will sell them a higher-speed Supervisor module. Ultimately, this means the introduction of a new Supervisor or selling the Supervisor 720 into the wiring closet, which would be a significant upgrade for most organizations.

Extreme officials wouldn't tell us the capacity of its switching interfaces. We know, though, that Extreme rate-limits its G48Pe modules by 2-to-1.

Extreme offers more expensive modules-for example, modules that the company claims will deliver line-rate performance across all 1000BaseT ports. This suggests that Extreme users will have sufficient capacity in their switch to accommodate 802.11n access points.


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