Ethernet breaks free of its shackles

ITU-T has recently consented to Recommendations that pave the way for Ethernet over carrier networks. As operators begin to migrate to an IP infrastructure, Ethernet provides an obvious transport layer. The new Recommendations progress Ethernet from a LANconnectivity technology to a carrier class delivery mechanism.

Ethernet has been with us for 30 years-it's a robust technology that is relied upon by 95% of businesses to carry their internal data traffic. It's simply a logical progression to push it out into the wider network.

The new Recommendations make way for Ethernet over ATM, MPLS, SDH, etc. The ability to provide 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 10-Mbit/sec and 10-Gbit/sec range currently offered. Further, the standards provide reduced operation complexity and improved scalability for carriers.

The Recommendations allow enterprises to exist on one Ethernet-based LAN across a number of locations without the need to interface with a different technology (e.g., Frame Relay or ATM) 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. Following are the Recommendations:

  • ITU-T G.8021/Y.1341 specifies both the functional components and the methodology that should be used to specify Ethernet transport network functionality of network elements.
  • ITU-T G.8011/Y.1307 describes a framework for network-oriented characteristics of Ethernet services.
  • ITU-T G.8012/Y.1308 specifies the Ethernet user-to-network interface (UNI) and network-to-network interface (NNI).
  • ITU-T G.8011.1/Y.1307.1 defines the transport architecture for carrying Ethernet characteristic information over dedicated-bandwidth point-to-point connections provided by SDH, ATM, PDH, MPLS, or OTH (Optical Transport Hierarchy) server layer networks.

Paolo Rosa is the counsellor for ITU-T Study Group 15, the lead study group onaccess-network transport and optical technology. He can be reached at +41 22 730 5235 or

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