scope:

This Recommendation specifies mechanisms for operations, administration and maintenance (OAM) for multi-protocol label switching transport profiles (MPLS-TPs) that can be applied in packet transport networks (PTN). It defines mechanisms for user-plane OAM in MPLS-TP networks to meet the MPLS-TP OAM requirements defined in [IETF RFC 5860]. It also specifies the MPLS-TP OAM packet formats, syntax and semantics of MPLS-TP OAM packet fields.

The OAM mechanisms defined in this Recommendation assume common forwarding of the MPLS-TP user packets and MPLS-TP OAM packets. In transport networks, the OAM return path is always in-band.

The MPLS-TP OAM mechanisms described in this Recommendation are applicable in network scenarios, as described in Annex A, and apply to co-routed bidirectional point-to-point MPLS-TP connections. Unidirectional point-to-point and point-to-multipoint MPLS-TP connections will be addressed in a future version of this Recommendation.

This Recommendation provides a representation of the MPLS-TP technology using the methodologies that have been used for other transport technologies (e.g., synchronous digital hierarchy (SDH), optical transport network (OTN) and Ethernet).¹

¹ This ITU-T Recommendation is intended to be aligned with the IETF MPLS RFCs normatively referenced by this Recommendation.