Cisco to meld Ethernet, ATM Nets

Cisco this week will present enhancements to its high-end LAN switch that will let users more tightly integrate Ethernet and ATM environments into converged voice and data nets.

The new products for the Catalyst 8500 series switches are intended to tightly couple Layer 3 packet forwarding with ATM switching. This may help users build seamless multiservice backbones -- to include voice, video and data -- for WANs, and campus and metropolitan-area networks.

The products also address what until now has been a shortcoming in the Catalyst 8500 switches: segregated ATM and packet switching that allows users to deploy only one or the other.

With one platform that combines campus Layer 3 switching with ATM multiservice switching, the Catalyst 8500 will go up against Cabletron's SmartSwitch 9000, which has an integrated packet- and cell-switching matrix; 3Com's CoreBuilder 9000; and Fore's Hydra frame and cell switching platform.

The new products include the ATM Routing Module (ARM), daughtercards for managing access-control lists, and eight-port Gigabit Ethernet modules, according to sources.

Also on tap for the Catalyst 8500 line are its first OC-48 ATM modules, WAN interfaces that perform inverse multiplexing and ATM/Layer 3 switching uplinks for wiring closet switches, the sources say.

Cisco declined to comment on the upcoming product splash. The new gear is expected to ship by year-end.

The ARM is an integrated packet/cell switching backplane that performs Ethernet-to-ATM bridging and routing. It will support 64,000 routes and 64 LAN Emulation clients when it ships this quarter. It will support Multi-Protocol over ATM in the fourth quarter.

Catalyst 8500 users today have to install separate backplanes for packet and cell switching, a kludgy and expensive requirement for those looking to bridge Ethernet workgroups at the edge of an ATM core network.

Integrating packet and cell switching on a common backplane will not penalise 8500 users who were attempting this with separate backplanes, says Esmeralda Silva, an analyst at International Data Corp.

Cisco offers other packet-to-cell switching options with its Catalyst 5500 and LightStream 1010 switches, but those are older, lower-end and less functionally sophisticated offerings than the Catalyst 8500.

The Access Control List (ACL) daughtercards will fit onto existing Catalyst 8500 line cards.

The daughtercards filter IP and IPX data and read IP Precedence bits to determine quality of service (QoS).

In the fourth quarter, ACL hardware will be embedded into new Catalyst 8500 line cards that will determine QoS from Differentiated Services (Diff-Serv) code points, per-flow queuing and IP Type-of-Service (ToS) fields, in addition to IP Precedence.

Diff-Serv is an IETF standard for IP QoS. Per-flow queuing prioritises traffic based on packet flows, rather than individual packets.

IP ToS and IP Precedence are bits in the packets that can be set to establish priority.

The eight-port Gigabit Ethernet line cards are designed for wiring closet and server farm aggregation. They will increase the Gigabit Ethernet density of the 13-slot Catalyst 8540 from 16 ports to 64 ports.

This hits home with some users.

"We're definitely going to need those cards," says Stan Christensen, senior network engineer at PeopleSoft in Pleasanton, California.

"The 8540 for us is a core switch. Most everything that connects to it, we're moving to gigabit. Anything we can do to get more density on those would be great because you only get eight functional slots, which is really not a lot," he says.

For gigabit ATM, Cisco will roll out modules that support 2.5Gbit/sec OC-48 ports for the Catalyst 8500. This quarter, Cisco will unveil cards that sport four OC-12s along with one OC-48.

In the fourth quarter, Cisco will add dual-port OC-48 boards to the mix.

On the WAN side, this quarter and next Cisco will release eight-port T-1/E-1 ATM inverse multiplexing modules for the Catalyst 8500 line.

These modules will allow users to incrementally increase WAN bandwidth beyond T-1 when procuring a T-3 circuit would be too expensive.

The ATM uplinks for the Catalyst 8540 will emerge in the fourth quarter. They will support one OC-12 plus one Gigabit Ethernet port over single-mode or multimode fibre.

Cisco in the fourth quarter is also expected to expand the Layer 3 capabilities of the Catalyst 8540 with support for Jumbo Frames, the Common Open Policy Service (COPS) protocol and Intermediate System-to-Intermediate System, VINES and DECnet routing.

With a maximum size of 9Kbytes, Jumbo Frames were created to alleviate processor interrupts that occur when servers receive a Gigabit Ethernet packet.

COPS is an IETF standard for disseminating network security and QoS policies from a server to network devices.

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