The Geneva-based International Telecommunications Union (ITU) has approved a set of global industry standards for Ethernet that will extend its flexibility and simplicity to carrier networks. The standards outline a way for Ethernet – a widely used local area network (LAN) – to link any number of endpoints

in a wide area network

(WAN), or simply as a service delivery mechanism.

The news marks Ethernet’s progress from a LAN connectivity technology to a carrier-class service delivery technology. The ability to offer Ethernet services means that carriers will be able to offer considerably improved flexibility to customers through a much simpler and lower cost interface. It will allow users to specify exactly how much bandwidth they want between the 10Mbit/s and 1Gbit/s range currently offered. Further, the standards provide reduced operation complexity and improved scalability for carriers.

The work according to Peter Wery, chairman of the ITU Study Group responsible for the issue, is driven by common sense, “”Ethernet is the access interface of choice. Ninety-five per cent of LAN infrastructure is based on Ethernet. It’s quite simply the most logical next step to extend its reach beyond the enterprise.””

Wery adds, “”This new set of recommendations describes Ethernet in a way that allows it to be deployed in a carrier network, over ATM, MPLS, SDH etc. It’s important because it provides end-users, from small and medium sized enterprises upwards, and service providers with a simple, cost-effective and yet robust and scaleable solution. This is exactly what the market needs.””

The recommendations (ITU-T G.8010/Y.1306, G.8011/Y.1307, G.8012/Y.1308, G.8012.1/Y.1308.1, G.8021/Y.1341) allow enterprises to exist on one Ethernet based LAN across a number of locations without the need to interface with different technology? Frame Relay or ATM for example – between sites. So, the flexibility of Ethernet can be extended over the WAN – without the need for additional customer premises equipment, or indeed any additional equipment at the carrier end.

Ethernet Standards

ITU-T G.8021/Y.1341 – This recommendation specifies both the functional components and the methodology that should be used in order to specify Ethernet transport network functionality of network elements; it does not specify individual Ethernet transport network equipment as such.

ITU-T G.8011/Y.1307 – This document describes a framework for network-oriented characteristics of Ethernet services.

ITU-T G.8012/Y.1308 – This recommendation specifies the Ethernet UNI and the Ethernet over Transport NNI. The detailed requirements are specified in a number of ITU-T Recommendations, IEEE Standards and IETF RFC.

ITU-T G.8012.1/Y.1308.1 – This recommendation defines the transport architecture for carrying Ethernet characteristic information over dedicated-bandwidth, point-to-point connections, provided by SDH, ATM, PDH, MPLS, or OTN server layer networks. This type of service is referred to as Ethernet Private Line (EPL) service. The recommendation uses the modeling methodology described in ITU-T Rec. G.805 and G.809 and uses the functional components defined in the technology specific server layer network Recommendations.

ITU-T G.8010/Y.1306 – This recommendation was consented in October 2003 and is the first in the series of Ethernet and Ethernet over Transport related recommendations. It describes the functional architecture of Ethernet networks using the modeling methodology described in ITU-T recommendation G.805 and G.809. The Ethernet network functionality is described from a network level viewpoint, taking into account an Ethernet network layered structure, client characteristic information, client/server layer associations, networking topology, and layer network functionality providing Ethernet signal transmission, multiplexing, routing, supervision, performance assessment, and network survivability. The functional architecture of the server layer networks used by the Ethernet network is not within the scope of this recommendation. Such architectures are described in other ITU-T recommendations or IETF RFCs.

ITU-T G.8010/Y.1306 is based on the Ethernet specifications in IEEE Std. 802.1D-2003, IEEE Std. 802.1Q-2003, IEEE Std. 802.3-2002 and developments of provider bridged networks. Furthermore the architectural aspects of provider bridges currently being defined in IEEE P802.1ad task force are taken into account.

ITU-T G.8010/Y.1306 defines Ethernet maintenance entities, but the specific impact on the transport functions of connection monitoring in a connectionless layer network is not addressed. Ethernet network survivability is intended for inclusion in a future version.

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