scope:

This Recommendation describes the telecommunication network as a transport network from the viewpoint of the information transfer capability. A telecommunication network is a complex network that can be described in a number of different ways depending on the particular purpose of the description.

This Recommendation provides a set of constructs (definitions and diagrammatic symbols) and the semantics that can be used to describe such a viewpoint. A transport network transfers user information from a sender at one location to a receiver at another location.

A transport network can also transfer various kinds of network control information, such as signalling, and operations and maintenance information for the control functional group.

This Recommendation describes the functional architecture of transport networks in a technology-independent way. The generic functional architecture of transport networks provides the basis for a harmonized set of functional architecture Recommendations for specific layer network technologies, including those that use connection-oriented circuit-switching (CO-CS) or connectionoriented packet-switching (CO-PS) and connectionless packet switching (CL-PS), as well as a corresponding set of Recommendations for management, performance analysis and equipment specifications.

This Recommendation specifies the architectural constructs that are required to describe a transport network. The theoretical material that was used as the basis for these definitions is provided in Annex A (concepts), Annex B (properties of systems) and Annex C (properties of communications).