RFC 926 December 1984 1 SCOPE AND FIELD OF APPLICATION This International Standard specifies a protocol which is used to provide the Connectionless-mode Network Service as described in ISO 8348/DAD1, Addendum to the Network Service Definition Covering Connectionless-mode Transmission. The protocol herein described relies upon the provision of a connectionless-mode subnetwork service. This Standard specifies: a) procedures for the connectionless transmission of data and control information from one network-entity to a peer network-entity; b) the encoding of the protocol data units used for the transmission of data and control information, comprising a variable-length protocol header format; c) procedures for the correct interpretation of protocol control information; and d) the functional requirements for implementations claiming conformance to the Standard. The procedures are defined in terms of: a) the interactions among peer network-entities through the exchange of protocol data units; b) the interactions between a network-entity and a Network Service user through the exchange of Network Service primitives; and c) the interactions between a network-entity and a subnetwork service provider through the exchange of subnetwork service primitives. ISO DIS 8473 (May 1984)