Service quality still in the ether

BEFORE THEY CAN DO SO, however, someone must determine what working together means. Someone must determine what service quality and performance mean. They have to get down to the basics of defining the attributes of an Ethernet service and by what metrics quality is determined. Today, that responsibility falls to the Metro Ethernet Forum and Iometrix, the company that runs the lab for the forum.

The MEF has a certification program for carrier Ethernet services. The actual certification is referred to as MEF 14-Abstract Test Suite for Traffic Management. This MEF certification ensures conformance to the MEF Quality of Service attributes. The first round of certification for Ethernet equipment was announced this summer at Globalcomm 2006 (see figure on page 30).

The MEF sees this certification as a major step toward making Ethernet truly carrier-class, in part because it provides clear, specifications-based guidelines for the formulation of SLAs. MEF 14 certification covers two sets of MEF Service Attributes: service performance and bandwidth profiles.

Service performance of Ethernet virtual circuits is determined by the following three attributes: frame delay, frame delay variation and frame loss ratio. Bandwidth profiles include four attributes: committed information rate, committed burst size, excess information rate and excess burst size. Together with MEF 9, it covers the complete set of carrier Ethernet service attributes defined in the core definitional technical document MEF 10.

The tricky part for the MEF, and Iometrix in particular, was determining the values of these attributes that translated to a level or performance that would support whatever services that service providers threw on their Ethernet networks.

“What the heck did we know when we started?” asked Bob Mandeville, president and founder of Iometrix. “We developed a formula that gave us a stable of values, then we tested 41 products and took the standard deviations, the averages and the mean deviations, etc. Turned out our original table was within microseconds of the standard deviation that we were actually measuring on the systems. We were very proud.”

The objective of the certification, Mandeville said, was to go through the list of attributes and one by one and raise the bar for Ethernet to a carrier-grade level. He said that through testing, it was determined that the equipment makers that brought their equipment to the process were for the most part ready for the challenge.

Next, the MEF will add metrics and certification for operations, maintenance and administration (OA&M) for Ethernet in the first mile (EFM.) “The program is taking it one piece at a time. We talked about performance, now the next step is management. It's a huge deal for service providers,” Mandeville said.

He added that multi-vendor element management systems don't speak to each other so a standard for management requirements is important.

Mirna Mekic, the product line manager at JDSU responsible for the Ethernet strategy of the company's portable test gear, said the MEF certification process was a work in progress. As a member of the MEF, she looks forward to the process move on to end user devices such as set top boxes and residential gateways.

“The MEF will have to account for those elements that are in the house as well,” Mekic said.

Mekic also would like to see OA&M for Ethernet get to the capability level of Sonet and synchronous digital hierarchy services where alarms can be reported in real time and data can be provided to build test cases that help predict errors and trouble before it happens. “That's really what will bring this word “carrier grade” to its real meaning,” she said.

MEF CERTIFIED

The Metro Ethernet Forum announced the first round of certification for carrier Ethernet in June during Globalcomm. Forty systems from 15 vendors were certified.

ACTELIS NETWORKS
ADVA OPTICAL NETWORKING
ALCATEL
ATRICA
CISCO SYSTEMS
EXTREME NETWORKS
FOUNDRY NETWORKS
FUJITSU COMMUNICATIONS
HATTERAS NETWORKS
LUCENT TECHNOLOGIES
MRV
SIEMENS
TELLABS
T-PACK
WORLDWIDE PACKETS

Source: Metro Ethernet Forum

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