Blueprint: Metro Ethernet

Metro battle: MPLS vs. Ethernet

MPLS has won the battle within core networks and has become the dominant internetworking technology. Some argued that MPLS should be extended to the network edge. Ethernet, the most successful networking technology ever developed, has won in the enterprise environment and is being extended to the metro. Will this success limit MPLS to the network core?

Sustaining the Ethernet Ecosystem: The Need for 100 Gigabit Ethernet

Ethernet's ubiquity and this inexorable demand for bandwidth are pushing the industry towards the next generation of Ethernet technology -- 100 Gigabit Ethernet. Vendors currently involved in developing the next generation of Ethernet anticipate it will be 2010 to 2012 before 100 GbE products are ready to ship. Here's the business case.

Metro Ethernet Will Require New OAM Tools

The advent of Ethernet as a Metropolitan and Wide-Area Networking technology has driven the need for a new set of Operations, Administration and Maintenance (OAM) protocols. Service provider networks are large and complex with a wide user-base, and they often involve different operators that must work together in order to provide end-to-end services to enterprise customers. Enterprises have managed Ethernet LANs primarily with protocols such as SNMP, ICMP echo (or IP Ping), and IP Traceroute. However, Ethernet in the service provider space is an entirely different ballgame.

VPLS Enables Ethernet Everywhere

The widespread adoption of MPLS in provider networks since the late 1990s has enabled many network benefits, such as traffic engineering, consolidation of multiple networks to a single IP/MPLS infrastructure, operationally efficient VPN services, increased resiliency, and better control of QoS parameters. In the coming years, VPN backbones of service providers may grow to immense sizes. This challenge requires requires an approach to service architecture that emphasizes scalability while preserving simplicity and resiliency. This is where VPLS enters the picture. VPLS delivers a multipoint-to-multipoint Ethernet service that can span multiple metro areas, and that provides connectivity between sites as if they were attached to the same Ethernet LAN.

Scaling Ethernet: QoS and Resiliency for the Metro

The mass rollout of Ethernet infrastructure has been predicted for some time, fueled by the promise of triple play, IP-video delivery, VoIP and other services adding to the service provider's revenue base. However, current service delivery for Ethernet at the edge won't cut it for a variety of reasons, including problems with scale, QoS and resilience. VPLS/MPLS, which is ideal for the core of the network, is costly and complex to extend to the customer premise, as the technology cannot easily handle video broadcasts, consists of an unwieldy point-to-point architecture and is costly to operate for the carrier when used in this way. Solving these scalability and manageability issues is now the focus of a new IEEE project approved in late 2004 known as 802.1ah. The new project, officially titled �Provider Backbone Bridges� will define an architecture and bridge protocols allowing interconnection of multiple VLAN-based networks to scale to over 1 million service connections.

As providers look to put an increasing number of services over an Ethernet infrastructure, addressing the scalability and manageability challenges will be key. The IEEE 802.1ah study group is a move in this direction and many vendors are now supporting this study group, which will meet again in March 2005 to move the standard process forward.

Building Large Metro Ethernets Requires MPLS

With continuous technology advances, service providers and end users are turning to Ethernet to enable a wide variety of next generation services. Whereas bridging has traditionally been used to extend Ethernet networks, carrier-grade networks will need to use MPLS for large-scale MPLS deployments.

Collapsing the Network Layers with Metro Ethernet

Traditionally, service providers have preferred a layered topology for their networks, relying on an access layer, an edge aggregation layer and a core aggregation layer. By leveraging high density Ethernet switches and routers that have robust resiliency features to guarantee availability, service providers can collapse the traditional multi-layer network topology, while differentiating their offerings to wield a competitive advantage in the marketplace.