Cisco boosts core LAN switch features

Catalyst 6000 gets 256G bit/sec switch fabric, management and Gigabit Ethernet modules.

By Jim Duffy
Network World, 09/25/00

SAN JOSE - Cisco last week unveiled enhancements to its Catalyst 6000 LAN-switching line designed to improve performance, protocol handling and network service delivery.

The hardware and software extensions are intended to help corporate customers and service providers build out their networks to securely access Web-enabled applications and content, and support changing traffic flows. The products include an upgraded switch management, or "supervisor," module; two new Gigabit Ethernet modules; and a new switch fabric module that utilizes Cisco's Express Forward (CEF) technology to improve packet and flow performance.

Cisco is also integrating a so-called Intrusion Detection System (IDS) module into the Catalyst 6000 family for secure access to applications and corporate information. The services aspect of the announcement addresses enhanced availability and quality of service (QoS).

The Catalyst 6000 is Cisco's strategic Layer 3 packet switch for the backbone and core of corporate networks and service provider hosting networks. It is the foundation of Cisco's infrastructure offerings for converged IP telephony networks, and it competes with Foundry Networks' BigIron, Extreme Networks' BlackDiamond, Enterasys Networks' SmartSwitch Router and Nortel Networks' Passport 8600 offerings.

The cornerstone of Cisco's new offerings is the integration of CEF in the Catalyst 6000 line. CEF is designed to accommodate the increasing numbers of short duration data flows associated with Web-based applications and interactive sessions.

CEF is intended to overcome the limitations of cache-based switch architectures - such as the current iteration of the Catalyst 6000 - which consumes CPU cycles to maintain route information in cache memory. CEF uses a so-called Forwarding Information Base to mirror the contents of the routing table and eliminate the need to maintain a route cache.

This enhances forwarding performance across multiple flow connections, Cisco says, because packets do not have to go to the supervisor modules to get forwarding instructions.

CEF is embodied in the new Supervisor Engine 2 and two 16-port Gigabit Ethernet modules for the Catalyst 6000. One of the new Gigabit Ethernet modules is targeted at data centers and scales up to 15 million packet/sec via a Distributed Forwarding Card daughter module that supports CEF.

The second Gigabit Ethernet module is intended for service providers and scales to 24 million packet/sec via CEF. It enables the Catalyst 6000 to support up to 112 nonblocking Gigabit Ethernet ports per system.

The new crossbar switch fabric module scales the Catalyst 6000's switch capacity to 256G bit/sec from 32G bit/sec in a bus-based backplane. The supervisor module and the switch fabric modules are redundant.

Current Catalyst 6000 modules and the new modules can operate in the same chassis, but distributed CEF-based switching is only supported on new modules.

On the software services front, high-availability enhancements include stateful failover and hitless software upgrades. Stateful failover mirrors the primary Supervisor Engine configuration on a redundant Supervisor Engine. Should a failure occur, stateful failover enables the redundant Supervisor Engine to recover without having to relearn Layer 2 or Layer 3 states.

Hitless software upgrades enable upgrades to new software while the switch remains active, eliminating the need to temporarily remove the switch from service.

Enhanced QoS services include burst protection for applications and specific user traffic, and "strict" priority queues for delay-sensitive traffic, such as voice or other high-priority applications.

For security, the IDS module supports TCP session termination and access control list configuration in the event a denial-of-service attack is detected. It also provides scalable traffic monitoring by load balancing across multiple modules, Cisco says.

The switching fabric module costs $7,495, the Supervisor 2 module $34,995, the 16-port Gigabit Ethernet module for enterprises $24,995 and the IDS module $14,995. These are available now. The Distributed Forwarding Card costs $11,995 and the 16-port Gigabit Ethernet module for service providers $41,995. These will be available in October.

Cisco: www.cisco.com