Options increase for gigabit boxesFlexibility, higher port densities, and more bandwidth at the core of chassis-based routing switches
By Stephen Lawton
The launch this month of several chassis-based routing switches promises to provide IS managers with a plethora of network design and configuration choices.
Cisco Systems Inc., NEO Networks Inc., Packet Engines Inc., and NBase Communications are among the companies unveiling chassis-based systems at and before the NetWorld+Interop show in Las Vegas next week.
The four- to eight-slot chassis designs, most of which use the same blades as the vendors' larger models, give IS managers greater port concentration and interface options in the wiring closet while building on an existing infrastructure.
IS managers may want to consider the chassis-based systems over stackable models if they anticipate significant growth in the near term, according to Deborah Tate, an independent network designer and consultant in Plano, Texas.
Because users and network-attached equipment move frequently, the flexibility of a chassis can be significantly greater than that of fixed-configuration boxes, she added.
Today Cisco announced the Catalyst 8500 series multilayer switch. The two models, which are targeted at backbone environments, are Cisco's first IP/IPX-only routers and the company's initial entry into the emerging class of limited-protocol, gigabit-Ethernet routing switches, according to Alan Marcus, director of network design and technology at Cisco in San Jose, Calif.
The 8500 series marks a significant jump in performance compared with Cisco's current generation of routing switches. Whereas the 5500 model operates at about 180,000 packets per second (pps), the 8500 line can route about 21 million pps.
Also today, Packet Engines launched its PowerRail 5200 family of routing switches, including the PowerRail 2200 for wiring closets. And NEO Networks plans to unveil its StreamProcessor 1000, a smaller version of its StreamProcessor 2400 routing switch that is capable of serving as a backbone router or in a wiring closet, the company said.
The NBase MS 5000HD, expected to be announced at N+I, is aimed at wiring closets and the network edge to aggregate metropolitan-area network traffic.
If a slot in the chassis system fails, the time it takes to move a blade from one slot to another is significantly less than it takes to replace a box--and all the associated cables--with another one, she said. It also lets the IS manager schedule the repair or replacement of the chassis rather than have part of the network down for an extended period of time.
Chassis-based units can be less difficult to configure and manage in centralized network environments, such as buildings that have just one wiring closet per floor and a centralized server room.
Although noting that switch prices have been falling in recent months, Tate cautioned IS managers not to get caught in the "network future-proofing" trap of buying more chassis than they require. She suggested that IS managers opt for a chassis that is 50 percent populated at the outset; it would be an unnecessary expense, for example, to buy a 16-slot chassis if the IS manager only planned to install four blades initially.
In addition to being able to add blades to grow the network without buying new boxes, bandwidth also improves in a chassis-based system, said Quinn Snell, an assistant professor at Brigham Young University in Salt Lake City.
"Chassis-based switches eliminate the bandwidth bottlenecks of stacking multiple standalone routing switches," he noted. When connecting several standalone boxes together, he said, the network becomes limited to the cable connections instead of the chassis' backplane capacity.
Additionally, having a chassis that uses the same blades as others in the network can be a benefit, according to Snell.
For example, Catalyst 8510 blades can be used in 5500 series switches. Buying new blades for existing switch chassis, rather than buying a new router, can be easier to explain to those who approve expenditures, he said.
Snell, who is expecting the delivery this month of a Packet Engines PowerRail 5200, said part of his decision was based on having room to expand his system. He also anticipates adding the seven-slot PowerRail 2200 to the wiring closets to feed the core routing switch.
Despite the promises of chassis systems, compromise is sometimes required. Late last year, Corey Van Allen, systems manager at Primary Color Systems Inc., a prepress operation in Irvine, Calif., sought to purchase a chassis-based routing switch that would fit into his existing Cisco-based network and support a network of Apple Computer Inc. Macintosh desktops. At the time, Cisco's only routing switch was the Catalyst 5500, which lacked the backplane capacity and throughput Van Allen needed, so he considered other vendors' models.
Among Van Allen's reasons for wanting a chassis were its greater flexibility in network design options relative to a stackable switch as well as add-on capabilities after initial purchase. However, he could not get delivery of the chassis-based system he preferred, so he bought several fixed-configuration units from Foundry Networks Inc. Foundry is now offering chassis-based systems, and Van Allen said he plans to add a unit as his network grows.
Cisco's list price for the Catalyst 8510 chassis starts at $24,995.
NEO Networks' list price for the StreamProcessor 1000 chassis is $14,995. The units are due to ship by midyear.
The NBase MS 5000HD is priced at $2,495 for the chassis.
Packet Engines' PowerRail 5200 lists for $24,995, and the 2200 lists for $9,995.
For more information, contact Cisco Systems at (408) 526-4000, http://www.cisco.com;
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