Hello, As agreed on the last OGF, Jeroen and I have worked on the definitions of Adaptation, Adaptation Function and Adaptation Services. We propose four definitions to describe adaptation between network layers: Definitions: * Layer: A collection of Ports with common Characteristic Information (Characteristic Information is defined in ITU-T G800; we envision sublayers to be a separate layer too, but this is really up to technology-specific extensions). * AdaptationType: Abstract type describing the technology of embedding the data of one layer into the data of another layer. * AdaptationService: Adaptation capability in a topology or node. * Adaptation: Actual data transport function where data of one port is embedded in the data of another port. This can be a configured AdaptationService, or a static component. Properties: * AdaptationType is between two Layers (the client and server Layer) * AdaptationService is between two PortGroups (This is a new concept, see below) * Adaptation is between two Ports (the client and server Port) Context: * Adaptation and AdaptationService are part of a Topology or Node. * Adaptation can not be part of a cross-connect in a SwitchMatrix. * AdaptationService can not be part of a SwitchMatrixService. PortGroup concept: * PortGroup: a collection of zero or more Ports in a Node or a Topology. PortGroups can be used to describe between which Ports an Adaptation can be created from an AdapatationService, or similarly between which Ports a cross-connect can be made in a SwitchMatrix. Unidirectional: The above definitions for AdaptationService and Adaptation are for bidirectional adaptations (adaptation one direction and de-adaptation the other direction). We propose the following terms for unidirectional Adaptation and AdaptationService: * AdaptationSource: Embedding of data from a client port into a server port. ("adaptation") * AdaptationSink: Extraction of data out of a server port into a client port. ("de-adaptation") * AdaptationSourceService: AdaptationSource capability in a topology or node. * AdaptationSinkService: AdaptationSink capability in a topology or node. Regards, Freek and Jeroen