Layer 3, ATM coming to Cisco switches

Cisco Systems Inc. last month unveiled several key enhancements to its ATM switches designed to let users better integrate Layer 3 Ethernet networks with cell-based infrastructures.

The new products for the Catalyst 8500 and LightStream 1010 series switches are intended to tightly couple Layer 3 packet forwarding with ATM. This may help users build hybrid multiservice networks – combining voice, video and data – using frames and cells instead of one or the other.

The LAN and enterprise ATM markets are in decline. According to the Dell’Oro Group, the enterprise ATM switch market has contracted in five of the past seven quarters by an average of 10 per cent. In 1999, the worldwide market was US$776 million, down from US$1 billion in 1998, according to Dell’Oro. The market for Layer 3 Ethernet, meanwhile, exploded from US$620 million in 1998 to US$2 billion last year.

It therefore behoves vendors such as Cisco – which had a 25 per cent share of the enterprise ATM switch market in 1999, second to Marconi’s 30 per cent – to dress up their ATM switches with as much packet technology as possible to make them appealing to users curtailing their investments in ATM.

“Cisco’s trying to make the next step to what we’re calling next-generation networks, which is packet-switched,” says Eric Thompson, principal analyst at Dataquest in San Jose, Calif. “They’re just trying to fill out their product line so they can do packet-over-ATM and extend that out.”

On the competitive front, Marconi markets its ESX-3000 as an integrated Ethernet and ATM switch with a 20Gbps cell backplane. Nortel Networks Corp. has eight-port OC-3 and two-port OC-12 ATM modules for its Passport 8600 routing switch, but that product is positioned more as an Ethernet switch than an ATM one.

Enterasys’ SmartSwitch 9000 has an integrated packet- and cell-switching backplane, but the company is encouraging users to trade that switch for the new Matrix E7, a Layer 2 to Layer 4 frame/packet wiring closet switch that supports ATM uplinks. Enterasys also has the SmartSwitch 6500, which features a dual-bus backplane for integrating ATM and gigabit Ethernet.

Cisco’s new products for its five-slot Catalyst 8510 and LightStream 1010 switches include an ATM Routing Module (ARM) for routing between ATM and Layer 3 interfaces; software for the ARM that encapsulates IP-over-ATM; and access control list (ACL) daughtercards. Cisco is also adding inverse multiplexing ATM WAN interfaces to the 8510.

For the 13-slot Catalyst 8540 core switch, Cisco is unveiling OC-12c packet-over-SONET (POS) uplinks; dual-port gigabit Ethernet modules with pre-installed ACL hardware; and an OC-48c link that extends connectivity over longer distances.

The ARM is an integrated packet/cell switching backplane that performs Ethernet-to-ATM bridging and routing. It alleviates the previous requirement for users to install separate backplanes to bridge Ethernet workgroups at the edge of an ATM core network.

The ARM debuted last year for the 8540. That product supports 64,000 routes and 64 LAN Emulation clients.

The IP encapsulation over ATM software for the ARM is compliant with the Internet Engineering Task Force’s RFC 1483 specification. RFC 1483 defines how to encapsulate multiple protocols over ATM Adaptation Layer 5 (AAL-5). AAL-5 is a specification for adapting packets to ATM cells.

The ACL daughtercards are intended to let users extend router-type security and traffic control to the ATM switches.

The Inverse Multiplexing over ATM (IMA) module for the 8510 features eight T-1/E-1 ATM ports. It is designed to let users incrementally increase WAN bandwidth beyond T-1 when procuring a T-3 circuit would be too expensive.

The OC-12c POS uplink module for the 8540 is intended to help users scale their metropolitan area network and WAN infrastructures. In addition to an OC-12c POS link, the module features a gigabit Ethernet port, pre-installed ACL hardware and up to 256,000 routing table entries.

Cisco unveiled OC-12c ATM uplinks for the 8540 last year.

A pre-installed ACL daughtercard is also a feature of the new dual-port Gigabit Ethernet boards for the 8540. Previously, users had to purchase and install this daughtercard separately on the 8540’s switching and management engine to get router-like security on the switch. These gigabit Ethernet cards also support up to 256,000 routing table entries.

The “long-reach” OC-48c port adapter for the 8540 lets users connect sites up to 80 kilometers away at speeds of 2.5Gbps. The previous limit was 15 kilometres.

Pricing and availability of the new products was not available at press time. If the current ARM, ACL daughtercard and IMA modules announced last year for the 8540 are any indication, users can expect to pay US$25,000, US$4,000 and US$9,995, respectively.