The basic concepts of Operations, Administration, and Maintenance (OAM) and the functional roles in monitoring and diagnosing the behavior of telecommunications networks have been long term studied at the Layer 1&2 & Layer 3 levels. The current practice is that many technologies and layers have their own OAM protocols.
Today we see a large number of layer1/2/3 OAM protocols being well developed and some of them being successfully deployed, but how these OAM protocols in each layer can be applied to overlay networks(e.g.,NVO3,SFC,EVPN Overlay network) that use different various encapsulation protocols(e.g.,VXLAN, NVGRE, GENEVE) to provide better OAM visibility is still a challenging Issue.
When operating networks with more than one technology in the overlay network, maintenance and troubleshooting are achieved per technology and per layer, operation process can be very cumbersome since OAM is not defined to cross layer boundaries in the data plane. Another challenge is presented by use of different technologies at different part of the network and corresponding OAM on the same layer of adjacent network domains. Stitching different OAM using different encapsulation methods at the same layer of adjacent network domains is often not defined and left to proprietary solutions.
OAM-related discussions initially took place on the TIME mailing list. Because the TIME name was confusing, the TIME mailing list was closed and transitioned to LIME.
To see the collection of prior postings to the list, visit the Lime Archives: http://www.ietf.org/mail-archive/web/lime/current/maillist.html.