VPLS or PBT? Switch maker hammers out answer

Edge switch maker Hammerhead Systems this week announced enhancements to its HSX 6000 switch, including a “multiclass” implementation of VPLS and support for Provider Backbone Transport (PBT).

Virtual Private LAN Service is a multipoint-to-multipoint Ethernet LAN service that makes corporate offices in metro areas or across the country appear to be connected to the same LAN. It is based on MPLS technology, which service providers have made considerable investment in over the past decade to engineer traffic on their networks and found new VPN service offerings.

VPLS is one such recent new service.

PBT is marketed by proponents as a lower-cost, less-complex alternative to VPLS and MPLS for point-to-point Ethernet applications. There has been considerable FUD in the industry as to whether PBT can effectively replace MPLS and VPLS – indeed, PBT advocate Nortel has virtually eliminated itself from the VPLS equipment market -- but the technologies are largely aimed at different applications.

The debate is over, according to Hammerhead, now that its HSX 6000 switch supports both VPLS and PBT.

The company’s multiclass VPLS implementation enables as many as six classes of service from a single customer VLAN attachment. This, Hammerhead claims, provides hierarchical quality-of-service enforcement for segregating services and enabling service providers to match application requirements to service-pricing options.

The HSX 6000’s PBT Service Gateway software enables service providers to interwork PBT deployments with the MPLS and VPLS installed base. The feature can provide an “on-ramp” capability for service providers to introduce PBT in areas of their networks where previously it may not have been considered as an intended direction, Hammerhead says.

Service providers can have both technologies exist in their network, with customer traffic and applications seamlessly interworked between them as necessary, Hammerhead claims. Thus, carriers can deliver existing MPLS and VPLS-based services while having trials for PBT for future requirements.

VPLS will be available later this month on the HSX 6000, while the PBT Service Gateway will be available in the second half of this year.