Recommendation X.212 DATA LINK SERVICE DEFINITION FOR OPEN SYSTEMS INTERCONNECTION FOR CCITT APPLICATIONS1 컴컴컴컴컴컴� 1 Recommendation X.212 and ISO 8886, Information processing systems - Data communications - Data link service definition, were developed in close collaboration and are technically aligned, except for the differences noted in Appendix I. 1. Appendix II to this Recommendation, which describes the relationship between connection-mode and connectionless-mode operation, is not present in ISO 8886. 2. Appendix III to this Recommendation, which defines a method for providing the OSI connection-mode data link service using X.25 LAPB compatible DTE procedures, is not present in ISO 8886. The addresses referred to in Table II/X.212 are DKSAP addresses. The connection-mode and connectionless-mode DLSs may both use the same DLSAP-addresses. Note - If the configuration allows any of these addresses to be known by the DLEntity on an a priori basis, then these DLSAP addresses need not explicitly be conveyed in the protocol. III.2 References In addition to the references identified in section 2 of this Recommendation the following references are applicable to this Appendix: Recommendation X.25 Interface between Data Terminal Equipment (DTE) and Data Circuit- terminating Equipment (DCE) for terminals operating in the packet mode and connected to public data networks by dedicated circuit. Recommendation X.75Packet-switched Signalling System between public networks providing data transmission services. ISO 7776 Information processing systems - Data Communications - high-level Data Link Control procedure - description of the X.25 LAPB-compatible DTE Data Link procedures.