Adva aids Ethernet handoff

Adva Optical Networking introduced a new demarcation device designed to manage the interface between carrier networks.

The company says to think of its new FSP 150CM as two back-to-back versions of the demarcation gear that Adva sells today for the handoffs between carriers and their enterprise customers. It has 16 slots, each capable of supporting 1 or 2 gigabit Ethernet or 10 gigabit Ethernet.

Adva wants its equipment to help ease the time-intensive nature of network-to-network interfaces (NNIs), which require carriers to agree, one-on-one, on how to preserve or translate the attributes of their Ethernet services as they hand them off. Where carriers have different class of service designations, carriers typically agree on a lowest common denominator.

“As long as one carrier’s got three classes of service and the other carrier’s got two, those handoffs are going to take some engineering,” said Fred Ellefson, Adva’s vice president of global marketing.

Industry standards groups including the Metro Ethernet Forum have been working on specifications that would provide a common framework for these NNIs, thus codifying and streamlining the process. Its unknown when those specs will be complete, but Adva said the two major standards it based the new product on—the IEEE’s 802.1ag and the ITU’s y1731—are likely to see only minor changes at this point.

“At this point, they’re implementable,” Ellefson said.

In particular, wireless backhaul applications have a level of scale that grants more uniformity to the process, making an easier case for Adva to put some pre-standard gear on the market. While wireline carriers might hand off dozens of services to reach out-of-territory branches of their enterprise customers, wireless operators might need hundreds or thousands of handoffs to serve their cell towers. With that kind of scale, wireless operators can dictate the handoff process en masse rather than negotiate individual interconnections. “If I’m an Ethernet carrier, I’ll bend over backwards for that business,” Ellefson said.

North American wireless operators are trialing the 150CM now, Adva said.

The device is shared by the two carriers that use it, which Ellefson analogizes by pointing to the way carriers share the CSU/DSU devices that interface routers with T-1s.

Because carriers want to measure and monitor services end-to-end, even if handed off to another network, carriers terminating Ethernet services must share some performance information. For example, the 150CM allows the ability to loop back both individual VLANs and multiple VLANs. As carriers hand off the traffic they want looped back, they mark the packets with a code that triggers the loop back at a maintenance end point. But to get those loop-backs automatically and uniformly, carriers need to share the addresses of the maintenance points in their network. “I’m not sure we’re totally there yet,” Ellefson said.