ITU-T Recommendations

This Recommendation defines the architecture requirements for a Data Communication Network (DCN) which may support distributed management communications related to the Telecommunication Management Network (TMN), distributed signalling communications related to the Automatic Switched Transport Network (ASTN), and other distributed communications (e.g., Orderwire or Voice Communications, Software Download). The DCN architecture considers networks that are IP-only, OSI-only, and mixed (i.e., support both IP and OSI). The interworking between parts of the DCN supporting IP-only, parts supporting OSI-only, and parts supporting both IP and OSI are also specified.Various applications (e.g., TMN, ASTN, etc.) require a packet-based communications network to transport information between various components. For example, the TMN requires a communications network, which is referred to as the Management Communication Network (MCN) to transport management messages between TMN components (e.g., NEF component and OSF component). ASTN requires a communication network which is referred to as the Signalling Communication Network (SCN) to transport signalling messages between ASTN components (e.g., CC components). This Recommendation specifies data communication functions that can be used to support one or more application's communication network.The data communication functions provided in the 11/2001 version of this Recommendation support connection-less network services. This revision of the Recommendation adds the support of connection-oriented network SCN services by including specific MPLS-based mechanism.This Recommendation forms part of a family of Recommendations covering transport networks.