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OAM Enhanced to Enable Carrier Ethernet Designation

September 27, 2011
By Susan J. Campbell, TMCnet Contributing Editor

Ethernet offers to increase the speed of the network and streamline data traffic through optimized data flows. Interestingly, OAM (Operation, Administration and Maintenance) functionality was lacking in Ethernet until recently and kept the technology from its current description of Carrier Ethernet as it was not considered to be carrier class.

As highlighted in the white paper, “Ethernet OAM Understanding Ethernet Link, Connectivity and Service OAM”, Carrier Ethernet has now acquired two types of OAM, one of which was developed by the ITU and IEEE (News - Alert) 802.1, and the other by the EFM taskforce. As a full-featured OAM mechanism, the former can run end-to-end and includes traditional OAM elements, such as RDI, AIS and performance measurement.

The other OAM, developed by the EFM taskforce, is focused on continuity monitoring of a single link and is targeted at access applications. The former protects the service layer of the carrier Ethernet, while the latter protects the physical layer, creating a complimentary relationship. What is unclear, however, is why there is a need for two different standards.

OAM refers to the monitoring of network operation by network operators. It is a set of functions the user relies on to enable detection of network faults and measurement of network performance. It also monitors the distribution of fault-related information. OAM ensures that network operators can easily comply with QoS guarantees, identify anomalies in the carrier Ethernet before they escalate and isolate and bypass network defects. This enables operators to offer binding service-level agreements.

When OAM is not present in the network or the Carrier Ethernet, there are increased demands for resources for continuous manual intervention to identify failures. Localized faults demand expensive truck rolls for identification and human performance measurements. Such networks have lower availability, longer downtimes and are more expensive to maintain.

Operators rely on OAM for Carrier Ethernet to help detect and localize network faults, examine and report on network status, monitor the performance of the network and provision and configure user parameters. In the layered network, each layer needs its own OAM so that network operators, service providers and end-users can effectively monitor the status of each function and make corrections without impacting others.

Since the introduction of Carrier Ethernet, the situation with OAM has changed significantly. Such networks must be managed by service providers. To achieve carrier-class designation, Ethernet MANs must support automated defect detection and performance measurement. Parameter monitoring at the service level is also required to guarantee SLAs.

With the emergence of two new standards in OAM, Carrier Ethernet is enabled and supported for optimal network performance.

Susan J. Campbell is a contributing editor for TMCnet and has also written for To read more of Susan’s articles, please visit her columnist page.

Edited by Carrie Schmelkin
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