ISO/IEC 8802-2:1998

Overview

ISO/IEC 8802-2:1998 (also published as IEEE Std 802.2:1998) defines the Logical Link Control (LLC) sublayer for Local and Metropolitan Area Networks (LANs/MANs). Part of the ISO/IEC 8802 family, this standard specifies the functions, services, protocol data unit (PDU) structure and bit-oriented procedures that implement the top sublayer of the data link layer in the OSI model. It describes how LLC interfaces with the network layer, the Medium Access Control (MAC) sublayer, and LLC management functions.

Key topics and technical requirements

• LLC services and primitives: Specifies the service behavior required between LLC and the network layer, and between LLC and MAC.
• PDU structure and bit-oriented procedures: Defines the format and exchange rules for LLC PDUs using bit-oriented control mechanisms.
• Three operation types:
  • Unacknowledged connectionless operation - exchange of PDUs without establishing a data link connection.
  • Acknowledged connection-oriented operation - establishment of a data link connection before exchanging information-bearing PDUs.
  • Unacknowledged connectionless with duplex capability - PDUs exchanged without a connection, with simultaneous send/request-return behavior permitted.
• Interfacing requirements: Specifies logical interfaces to the MAC sublayer and to network-layer service access points.
• Management and conformance: Includes management object definitions and conformance-related supplements incorporated in the 1998 edition.

Practical applications

• Implementation of protocol stacks for network devices (switches, bridges, routers, NICs) that need standardized LLC behavior.
• Development of interoperable LAN/MAN software and firmware where consistent data link services are required across different MAC technologies.
• Test and certification in conformance labs to ensure devices meet LLC protocol and PDU handling expectations.
• Reference for network architects and engineers designing multi-protocol network environments that rely on standardized data link services.

Who uses this standard

• Network equipment manufacturers and firmware developers (NICs, switches, bridges)
• Protocol implementers and embedded systems engineers
• Test labs and certification bodies
• Standards bodies and technical architects developing interoperable LAN/MAN solutions

Related standards

• ISO/IEC 8802 family (e.g., 8802-3, 8802-5, 8802-11) and IEEE 802 series - MAC and physical layer access methods referenced by ISO/IEC 8802-2.
• ISO/IEC 15802 series (LAN/MAN management and MAC service definitions) for related management and MAC service specifications.

Keywords: ISO/IEC 8802-2, IEEE 802.2, Logical Link Control, LLC, LAN, MAN, data link layer, MAC, PDUs, OSI model.