Historical
ISO/IEC 7809:1993
Information technology - Telecommunications and information exchange between systems - High-level data link control (HDLC) procedures - Classes of procedures
Describes the HDLC unbalanced classes of procedures, the HDLC balanced class of procedures, and the HDLC connectionless classes of procedures for synchronous or start/stop data transmission. The procedures use the HDLC frame structure defined in ISO/IEC 3309 and the HDLC elements of procedures described in ISO/IEC 4335.
International Organization for Standardization [iso]