• United States
by Steve Taylor and Joanie Wexler

MPLS-based meshed Ethernet services in the offing

Feb 26, 20042 mins

* Carriers investigate transparent LAN services over MPLS

Multi-point services that extend your Ethernet LAN into metro- and wide-area networks should be coming soon.

Service providers that offer IP VPN services over Multi-protocol Label Switching (MPLS) backbones have some relatively new technology available to them that enables them to deploy fully meshed transparent LAN services in the MAN and WAN. Carriers that use MPLS include AT&T, MCI, Equant, Infonet, Bell Canada and, increasingly, incumbent local-exchange carriers (ILEC).

According to the Cisco Web site, about 45 carriers worldwide are currently evaluating using Virtual Private LAN Service (VPLS) technology, which recently became available in Cisco gear, to deploy high-speed, multi-point Ethernet offerings. VPLS, an IETF Internet-Draft technology, is also supported in equipment from Juniper and Riverstone.

The IETF VPLS document, accessible at the first URL in the “Related Links” section, describes how carriers map your VLANs into a single “VPLS instance” across a single virtual or physical connection to give you multipoint transparent LAN services.

VPLS technology is more likely to be applied to service provider networks than enterprise networks. However, we mention it so that you know to investigate emerging VPLS-based services. All services in a VPLS appear to be on the same LAN, regardless of location.

For example, if you are interested in Ethernet-speed multipoint connectivity for delay-sensitive applications such as VoIP, such a service might interest you. Similarly, if you run protocols other than IP at Layer 3, a Layer 2 service would suit you better than an IP VPN. VPLS technology supports speeds to 10G bit/sec. What speeds will be available as subscriber services, of course, will be up to the carriers.

Note that there are Ethernet services available today from the carrier bigwigs, including AT&T, MCI, and Sprint. Most are based on SONET technology and involve the carrier configuring multiple point-to-point Ethernet connections to deliver the experience of a full mesh. VPLS, theoretically, should ease the provisioning of multipoint Ethernet services, thus boosting Ethernet service availability and, hopefully, rendering them less costly.