Switch start-up enhances aggregation

Hammerhead Systems last week enhanced its multiservice switch with software the company says will improve a customers' ability to aggregate Layer 2 services, such as Ethernet, as they migrate to Multi-protocol Label Switching.

Hammerhead's Layer 2.5 Aggregation Switch software for its HSX 6000 uses the pseudowire and Dry Martini techniques to merge Layer 2 operations and interworking methods with Layer 3 application awareness, the company says. Pseudowire emulates physical connections using a service ID label that defines the traffic type and QoS parameters; Dry Martini extends pseudowire to work over any infrastructure, such as SONET and ATM - not just MPLS.

Dry Martini is based on the IETF's Draft Martini specification for integrating Layer 2 services onto an MPLS core. (The martini wordplay is a bow to Luca Martini, the Level 3 engineer who conceived of a way to link legacy Layer 2 traffic, such as frame relay and ATM, to IP/MPLS backbones networks.)

Hammerhead says its HSX 6000 is in lab trials for pseudowire, Ethernet and Layer 2.5 aggregation applications, and that the company is driving the pseudowire Dry Martini technical drafts through the IETF for standardization.

The Layer 2.5 aggregation feature is particularly targeted at improving Ethernet aggregation for business and consumer broadband services. The HSX 6000 is based on an Ethernet service architecture, Hammerhead says, with support for native Gigabit Ethernet and Ethernet-over-SONET.

The HSX 6000 also can be used for three aggregation applications:

• High-density fan-in of traffic across a range of new and legacy service interfaces, media and speeds.

• Grooming and service-level details across a range of applications and protocols.

• Trunking across an ATM or MPLS backbone and control plane.

The HSX 6000 also features a service interworking capability for providers looking to roll out Ethernet services, such as point-to-point E-Line, to existing frame relay and ATM customers. Hammerhead's service interworking capability supports more than 1 million flows on one switch.

Layer 2/3 integration also is embodied in the switch's dual MPLS and ATM control planes. This is intended to provide native signaling and route control of MPLS paths and ATM virtual circuits.

Hammerhead's Layer 2.5 aggregation capabilities will compete with the multiservice edge aggregation features of switches from Lucent and Nortel, and routers from Cisco and Juniper. Traditional routers excel at IP packet forwarding, application awareness and processing of higher-order VPN services, but carry higher cost and complexity, and incomplete support for legacy services and deterministic QoS guarantees, Hammerhead says.

Layer 2 multiservice switches, meanwhile, offer the necessary Layer 2 operational attributes and QoS, but fail to effectively support the array of Ethernet services and IP application awareness, Hammerhead says.

Hammerhead says the Layer 2.5 Aggregation Switch software is included in the purchase of a HSX 6000 switch. It will be available in the first quarter of 2005.