Wide-Area Ethernet Services Advancing with Reliability Guarantees

The Metro Ethernet Forum (MEF) recently announced the first round of network gear certified to comply with its Ethernet services requirements. Certifications showing carrier compliance with MEF Ethernet services requirements demonstrate service providers' commitment and adherence to Carrier Ethernet. This development should help drive down provisioning costs.

Conformance with MEF requirements benefits enterprises in two ways: It lowers the cost of Ethernet services by commoditizing hardware used by carriers, and it assures customers that carriers can deliver reliable Ethernet services that meet SLAs.

Carrier Ethernet describes wide-area Ethernet services used for LAN extension and high-speed connections within a metropolitan area, nationwide and internationally. Early Ethernet services provided only best-effort service; Carrier Ethernet offers SLA reliability in a low-cost, high-speed WAN that joins LANs transparently.

MEF standard conformance will pave the way for seamless interoperation among service providers, Ethernet services equipment and customers. E-NNI (External Node-to-Node Interface) promises to simplify Ethernet services interoperability, for example, and hasten implementation among carriers by standardizing the interconnect requirements. The E-NNI specification is being fast-tracked through the MEF, as is a conformance test spec similar to the MEF 9 and 14 specs.

Carrier Ethernet looks like an Ethernet switch port. The preferred last-mile media for Ethernet services is fiber because it provides the best price-performance. EVCs (Ethernet virtual circuits) handle the LAN extension over the WAN; they're composed of two or more UNIs (user network interfaces) connected over a point-to-point E-Line and a multipoint E-LAN (see diagram at left).

The Service Is The Network

Representatives from Verizon, Bell South and other carriers say their customers don't want the unreliability of a best-effort Ethernet service. Customers from vertical industries--such as financial, manufacturing, retail and education--need predictable service levels for bandwidth, packet delivery, latency, jitter and loss.Carrier Ethernet costs 30 percent to 50 percent less than comparable WAN services. We expect the cost to drop further with increased competition and economies of scale within the carriers. Once the last mile has been run to the building, the service provider can easily provision up to the capacity of the last mile.

A potential benefit of Ethernet services is bandwidth-on-demand and class-of-service management. Smaller Ethernet services providers are leading the effort to offer rapid bandwidth reprovisioning. Yipes says it can implement provisioning changes within five minutes. XO Communications says it can implement changes within five days.

Your location will determine Ethernet service availability and competition. Availability depends on the existing fiber plant in the municipality. "About 12 percent of businesses have fiber coverage, and carriers are expanding coverage incrementally," says Dan O'Connell, Gartner's research director for enterprise network services and infrastructure. "Meanwhile, standardized Ethernet over copper and wireless are still being worked out."

More difficult to determine is whether a distributed enterprise can get all locations on Ethernet service from a single carrier. Some providers, such as Sprint, Verizon and Yipes, offer national and international Ethernet services, while smaller carriers, such as Optimum Lightpath and Qwest, offer only regional services for the most part.The MEF is bullish on the success of E-NNI, but Gartner's David Willis is bearish about it. "We had some interprovider peering using frame relay NNIs, and some companies built business models based on it in the late '90s. However, the current strategy for telcos is to go it alone; we're still waiting on MPLS interconnection between major players," he says.

The bottom line is that Ethernet services is enjoying a strong demand driven by promise of SLAs with Carrier Ethernet and simpler interconnections. More enterprises are running time-sensitive applications like database transactions and VoIP that need high throughput and predictable performance over the wide area. Carrier Ethernet promises to deliver that. We expect the number of carriers offering national and international Ethernet services to grow, regardless of the outcome of E-NNI. However, carriers that extend their geographic reach with E-NNI could provision Ethernet services more quickly and less expensively than carriers that insist on controlling the connection end-to-end, which may become a market differentiator.

Mike Fratto is an nwc senior technology editor based in our Syracuse University Real-world Labs&Reg;. write to him at [email protected].