Alcatel switches stack up

Alcatel SA in December is scheduled to start offering stackable 10/100Mbps Ethernet switches that pack much of the punch of enterprise chassis-based boxes.

Alcatel lags behind 3Com Corp., Cisco Systems Inc. and Nortel Networks Corp. in getting into the “virtual chassis” switch market, but at the same time leapfrogs them in several respects – namely, improved failover capabilities and delivery of up to 4Gbps links between each switch in a stack.

“Alcatel is saying it can offer carrier-class availability in a bunch of stackables, which is an interesting concept,” says Stan Schatt, vice president with Giga Information Group Inc.

While the new OmniStack 6600 switches are not Alcatel’s first stackables, they are its most advanced. The 24- and 48-port devices, which start at roughly US$170 per port, are meant to act as virtual chassis switches in high-density enterprise wiring closets or backbones.

Texas A&M University, a large Alcatel network shop that has been testing beta versions, plans to deploy 6600s mostly at the LAN edge. The College Station school expects to use them in areas that support real-time traffic, such as offices with voice-over-IP (VoIP) and IP video applications, according to Willis Marti, associate director of the school’s Computer and IS Networking Group.

“We like stackables a lot more than chassis-based products in the [wiring] closet,” Marti says. “It’s easier to manage,” because switches in the stack can be added and removed without changing any configuration files or shutting down a larger chassis. He also says it is a plus that each switch cannot act as a single point of failure – each has its own power supply.

The only downside to the stackables, he says, is that with their 1.5U (2.62 inches) form they take up more room than Alcatel’s previous 1U (1.75 inches) OmniStack 6148 switches.

As many as eight OmniStack 6600s can be linked with dual Gigabit Ethernet connections in a “cascade” loop configuration, in which each switch is linked to an adjacent switch. This provides a virtual backplane of 4Gbps for each switch port in the stack when each connection runs in full-duplex mode.

A stack of OmniStack 6600 switches can be controlled as a single network device, with one IP address. The stack can be viewed and configured as one device through SNMP-based tools and Alcatel’s OmniVista switch management software, which is used to manage its OmniSwitch 7000 and 8000 series chassis products. The switches support Layer 3 switching and other features found in high-end wiring closet chassis products, such as Open Shortest Path First, 802.1X authentication and quality of service.

Each switch in the OmniStack 6600 stack can act as the equivalent of a supervisor, or management module, from the chassis switch world. This lets any of the switches take over as the control module for the virtual chassis, the company says.

The 6600s will compete with products such as Cisco’s fixed-configuration Catalyst 2900 and 3500 boxes, which can be combined into a chassis-like device through the use of Cisco’s GigaStack technology. Nortel can do the same with its BayStack boxes, and Allied Telesyn has a similar technology.

3Com is looking to re-establish itself at the high end of the enterprise network market with its Extendable Resilient Network technology, which links fixed-configured boxes with high-speed interconnects as an alternative to chassis switch products.

Giga’s Schatt says Alcatel’s differentiators include its ability to offer 4Gbps connections between switches in a stack versus closer to 1Gbps links from others.

Schatt says the 6600’s failover scheme is an improvement over competitors’ offerings. Most vendors’ stacked switches become unmanageable as a single device if the supervisor switch fails, whereas the OmniStack can fail over to a back-up switch for controlling the stack.

Regardless, Alcatel has a challenge ahead in trying to win share from Cisco, Nortel and 3Com, which lead the fixed-configuration switch market. Alcatel held only 1.8 per cent of the overall US$15 billion LAN switch market last year.