1 This Recommendation defines the network-independent basic transport service applicable to Teletex and Group 4 facsimile terminals connected to the types of network mentioned in (a) above in terms of:
a) the transport services provided to the higher layer [the transport services are provided by the transport layer (layer 4) in association with the underlying services provided by the supporting layers 1 to 3];
b) the transport layer procedure (see § 5 below).
Note — The transport layer procedure for integrated services digital networks is for further study. The use of this transport procedure for other Telematic services and the use of other transport procedures is left for further study.
2 § 2 describes the transport service. § 3 describes the transport service implementation for different types of networks. § 4 outlines the guidelines for interworking between networks. § 5 specifies the transport layer procedure, and Annexes A and B provide associated state transition diagrams and tables respectively.