Cisco re-ARMs Catalyst 8500

Cisco this week unveiled a new ATM routing engine for its Catalyst 8500 switch.

The ATM Router Module (ARM) II allows users to combine Layer 3 packet and cell switching on the same platform. ARM II supports a wider range of standard data encapsulation techniques than ARM I.

Specifically, the ARM II offers switched virtual circuit (SVC) support for RFC 1483, which provides for multiprotocol encapsulation over ATM, and support for RFC 1577, a method for transporting "classical IP over ATM."

These software enhancements are designed to simplify network configuration and management, Cisco says. They eliminate the need for a user to specify destination paths within and among networks, which makes the networks easier to scale and increases stability and availability, Cisco claims.

Other features in the ARM II are the integration of access control lists (ACL) with a capacity for up to 256,000 routing-table entries. Previously, these features were only available on other Catalyst 8540 modules, such as the two-port Gigabit Ethernet module.

Integrating ACLs onto the ARM II provides security features at the point where data first enter the network, Cisco says. The support for up to 256,000 routing-table entries adds room for future network services and ensures scalability, Cisco says.

But users may not actually realize increased scalability with ARM II, analysts note.

"The ARM II limits the overall scalability of the platform," notes Current Analysis in a recent report. "The ARM II installed in a (five-slot) Catalyst 8510 can only route one quarter of all the traffic the switch is capable of switching. Two ARM II modules installed in a (13-slot) Catalyst 8540 can only route one eighth of all the traffic the switch is capable of switching. While it addresses issues such as SVC based provisioning and route table size, it still limits the overall capacity of the chassis."

Cisco plans to add more features to the Catalyst 8500 line, including Multi-protocol Label Switching, VPN features, interworking of IP class of service with ATM quality of service, and enhanced voice capabilities. Cisco also will announce managed network service applications for the switch.

"(ARM II) addresses shortcomings of Cisco's previous ARM module while helping Cisco strategically reposition the 8500 from an enterprise device to a service provider/customer premise device," Current Analysis states in its report. "Few enterprises depend on ATM for backbone connectivity, but some impact will be perceived, as Managed Service Providers deliver enterprise connectivity using the platform."

The ARM II costs $24,995 and is available now.

Contact Edge Managing Editor Jim Duffy

Other recent articles by Duffy