Protection for optical transport network with dual homed attachment circuits

Abstract

For protecting traffic on paths extending from a source client entity (CE) to a destination client entity (CE) via an optical transport network and attachment circuits at ingress (A,B) and egress (C,D) nodes, there are multiple paths within the OTN network, and the attachment circuits are dual homed. By sending () an indication of operational status of the dual homed attachment circuits within overhead associated with the traffic and sent with the traffic through the network, a selection can be made () of which of the provided paths and attachment circuits to use for the traffic, based on the indicated operational status, and on OTN fault detection, to protect against a fault in the attachment circuit or in the OTN network. Thus protection can extend across the edge nodes without the complexity and delays involved in interworking of separate protection schemes and without a control plane.