s covers the verification of the connectivity of data links, together with dynamic determination of the mapping between local and remote interface IDs. If link verification is not supported, these mappings must be provided by configuration. Link property correlation This is confirmation between neighboring nodes that the mappings between local and remote interface IDs and the aggregation of multiple data links into traffic- engineering links are consistent. Fault management Lightpaths typically traverse multiple data links going from ingress to egress. When this lightpath fails, LMP provides a way to localize which data link has failed. Authentication This provides cryptographic confirmation of the identity of the neighboring node. 8.6.1 Control Channel Management Control channel management is concerned with the negotiation and main- tenance of the LMP session itself. LMP Hello messages are used to confirm that the session is still running. Parameter negotiation is necessary to agree on values for per-session parameters such as Hello timeout periods, supported protocol levels, and support for optional protocol features: Control channel selection This is not currently within the scope of LMP, but nevertheless is an important requirement for LMP to work. LMP peers must know to use the same control channel(s) when they exchange LMP messages. Chapter 8 Parameter negotiation This enables a pair of LMP nodes to converge on a mutually acceptable set of configuration parameters. The protocol exchange involves three messages (Config, ConfigAck, and ConfigNack), each of which can contain a variable number of subobjects describing particular parameters (such as timeout values and support for optional protocol elements). The results of the parameter negotiation process are an agreement on timeout intervals for control channel maintenance and an agreement on the supported set of LMP capabilities. Control channel maintenance This involves an ongoing exchange of Hello messages between a pair of LMP nodes to confirm that the con