Ethernet Gains Determinism

They say necessity is the mother of invention; that certainly is the case with Ethernet. While carriers are intent on moving to Ethernet-based networks because of the lower cost basis, they are being prevented from moving forward until Ethernet can match the service levels end users have come to expect from frame relay and ATM services.

Ciena Corp.’s Core Director multiservice switch includes the new Ethernet Services Line Module.

To resolve this dilemma, a range of vendors at GLOBALCOMM announced solutions aimed at transforming Ethernet from a best-effort service to a deterministic transport mechanism.

“It’s not just based on transport anymore but on quality of service and deterministic performance and scale,” said Tom DiMicelli, Juniper Networks Inc.’s product marketing manager. “That’s an entirely new class of Ethernet products.”

To that end, Juniper announced new Ethernet service interface cards, available in the third quarter, for its M-series edge and T-series core routing platforms that feature QoS capabilities, so service providers can offer guaranteed SLAs for a variety of Ethernet services such as VLAN/transparent LAN, Layer 2 and 3 VPNs, VoIP and video over IP.

Ciena Corp. also has integrated a new Ethernet Services Line Module (ESLM) into its CoreDirector multiservice switch. Significantly, ESLM enables service providers to assign bandwidth profiles to each service so they can deliver a committed information rate, committed burst size, excess information rate or excess burst size.

“We have a traffic management component that controls how services come in and which ones get high priority,” said Vinay Rathore, Ciena’s director of service provider marketing. CoreDirector’s integration with ONCenter, Ciena’s network and services management system, enables automated point-and-click Ethernet service provisioning and management with the ability to enforce granular SLAs.

CoreDirector also brings rerouting capability to Ethernet and provides 100ms rerouting in the event of a disaster. “It’s not quite as fast as 50ms switching [standard with SONET], but it’s pretty damn fast,” Rathore said. “It’s more resiliency than you can get today on Ethernet services.”

Also at GLOBALCOMM, ADVA Optical Networking introduced its Etherjack Service Assurance technology, which enables carriers to offer, monitor and verify Ethernet SLAs across their own and leased infrastructures. “Now you can measure QoS. This should help get the Ethernet market moving forward,” said Fred Ellefson, vice president of Etherjack Alliances for ADVA, noting end-user customers who subscribe to frame relay and ATM services stick with them because of SLAs.

ADVA Optical Networking’s FSP 150CC

Etherjack Service Assurance monitors delay, delay variation, packet loss and network availability end-to-end across services on- and off-net. Because of its intelligent demarcation, Ellefson said one of the key applications for the FSP150CC is with carriers leasing access because it gives them greater visibility through the underlying carrier to the customer premises to determine quickly the responsibility for service-affecting problems.

The FSP150CC supports OAM at the link and service levels according to IEEE 802.3ah, and the emerging IEEE 802.1ag and ITU Y.1731 standards.

Foundry Networks Inc. also announced support for 802.3ah and 802.1ag in its new NetIron M2404 series of MPLS-enabled Metro Access switches, which seek to bring greater manageability and quality of service to carrier Ethernet services by extending MPLS functions like traffic engineering and fast reroute to the edge.

“A key requirement when you deliver services is to enforce SLAs end-to-end, not just in the core,” said Ken Cheng, vice president and general manager for Foundry Network’s service provider business unit. “Driving MPLS to the edge achieves end-to-end SLAs.”

Specifically, the M2404 creates an end-to-end MPLS tunnel for 50ms fast reroute, Cheng said. In addition, hierarchical QoS (or H-QoS) scheduling, inbound and outbound traffic policing and shaping features offer providers the ability to deliver advanced SLAs. “H-QoS is able to enforce QoS right where the customer connects, instead of deep into the network,” Cheng said, noting there are three levels of H-QoS — physical, VLAN and class of service. This means service providers can use one port to service multiple homes and within each home can deliver multiple services, Cheng said.

While extending MPLS to the edge is a popular approach for end-to-end management, Nortel is promoting a different notion it calls Provider Backbone Transport (PBT) technology, citing concerns that the more popular approach — MPLS from core to edge — doesn’t scale.

PBT is a point-to-point tunneling technology that enables service providers to specify the path that an Ethernet service should take across the network. It allows for QoS guarantees by reserving bandwidth for real-time services, and it provides for 50ms service recovery times should a connection fail. Together, these characteristics are designed to support live video and broadcast, multimedia, broadband data and voice services.

PBT is available today in Nortel’s Metro Ethernet Routing Switch 8600 and soon will be integrated into its Optical Multi-service Edge 6500 and other Ethernet-ready platforms.

For more about Ethernet, read our free eBook, "Ethernet Everywhere," sponsored by Zhone Technologies.