US Patent 9686167 Ingress node controlled path impairment protocol

An apparatus comprising a node configured to transmit operation, administration, and maintenance (OAM) connectivity frames, wherein the node adds an impairment notification indication to some, but not all of OAM connectivity frames transmitted by the node, wherein the impairment notification indication indicates the node's desire to receive notification of an impairment condition along the path. A network component comprising a receiver unit configured to receive multiprotocol label switching (MPLS) Ping frames, a circuit logic configured to add a downstream link impairment indication to responses to the MPLS-Ping frames, wherein the downstream link impairment indication comprises a type and a severity level for a path impairment condition, and a transmitter unit configured to transmit the responses to the transmitted MPLS-Ping frames.