available in its Metro Ethernet Networks portfolio, the new technology –
called Provider Backbone Transport (PBT) – is designed to allow service
providers to deliver the communication and entertainment services of the
future to consumers and companies across cities and countries.

Provider Backbone Transport transforms Ethernet technology, traditionally
restricted to small-scale, local networks, into a more reliable, scaleable and
deterministic technology making it suitable as the basis for fixed and mobile
carrier networks to deliver live video and broadcast, multimedia, broadband
data and voice services.

“Ethernet is a pervasive information transport technology due to its
simplicity and cost-effectiveness,” said Philippe Morin, president, Metro
Ethernet Networks Nortel. “Nortel is now improving Ethernet and putting its
simplicity and value at the heart of carrier networks.”
“As a technology developed for smaller, local networks, Ethernet has
lacked critical requirements that would enable service providers to take
advantage of its benefits across city and national networks. By determining
the specific performance of a network under any conditions and making it more
reliable, Nortel is helping service providers leverage the cost-efficiencies
of Ethernet to support crucial services like video, 3G mobility services, and
business connectivity services.”

Nortel is working with the support of some of the world’s largest service
providers and standards bodies to facilitate broad adoption of PBT as a metro
technology. A first-to-market version of PBT is already available in the
Nortel Metro Ethernet Routing Switch (MERS) 8600, with development also
underway to integrate the technology into the Nortel Optical Multiservice Edge
(OME) 6500 and other Ethernet-ready platforms.
“PBT has the potential to be a disruptive technology for service provider
metro networks,” said Stan Hubbard, senior analyst, Heavy Reading. “Its
promise of enabling more manageable and scalable Ethernet that is cost-
effective for metro network deployments makes it an attractive complement for
service providers with existing MPLS core networks.”

Traditional connectionless, best-effort Ethernet poses challenges for
service providers needing to guarantee service delivery and quality of service
(QoS) for real-time applications. PBT is a simple point-to-point tunneling
technology that adds determinism to Ethernet, enabling service providers to
specify the path that an Ethernet service should take across the network. PBT
allows for QoS guarantees by reserving bandwidth for real-time services, and
provides for 50 millisecond service recovery times should a connection fail –
matching the benchmarks set by today’s existing SONET and SDH optical
transport standards.
“Nortel has been working with several major service providers that are
very interested in the potential benefits of deploying PBT as a metro
networking technology,” said Morin. “PBT is designed to provide reliability
and determinism equal to SONET and SDH while retaining the cost and simplicity
of Ethernet – a combination ideal for a carrier network environment.”
PBT also helps resolve issues with Ethernet’s scalability, helping
conserve network resources that would otherwise be taken up by the constant
communications between large numbers of Ethernet devices in the network. In
addition, when PBT is paired with another pending Ethernet standard – Provider
Backbone Bridging (IEEE 802.1ah) – it is now possible for service providers to
scale Ethernet-based services to millions of users per metro area.