Organizational Unique Identifier

Description

The Organizational Unique Identifier (OUI) is a 24-bit number uniquely assigned to an organization by the IEEE Registration Authority. It forms the first half of a 48-bit MAC address. Within the 3GPP ecosystem, specifically for Edge Computing (EC) as defined from Release 12 onwards, the OUI is leveraged beyond its traditional networking role. It serves as a foundational component for constructing globally unique identifiers for Application Clients (ACs) and Application Servers (ASs) operating within the Edge Computing service architecture. These identifiers are crucial for service discovery procedures, allowing an AC to locate the appropriate AS providing a desired edge application. Furthermore, the OUI-based identifier is used in security contexts, such as within the TLS certificate for the EC service, to authenticate the AS. The integration of OUI into 3GPP standards provides a stable, well-understood, and globally administered namespace, preventing identifier collisions between different vendors and service providers in the distributed edge environment. Its use is specified in procedures for Edge Configuration and Service Discovery.

Purpose & Motivation

The OUI was incorporated into 3GPP standards to solve the fundamental problem of uniquely identifying entities in a decentralized, multi-vendor Edge Computing landscape. Prior to its adoption, 3GPP lacked a standardized, globally unique mechanism for identifying application-level entities outside the core network's traditional subscriber and network element identifiers. The motivation stemmed from the need for Edge Computing, where application servers from various providers must be discoverable and addressable by user equipment in a trusted manner. Using the pre-existing IEEE OUI scheme provided an immediate, robust solution without inventing a new, complex administration body. It addresses limitations of ad-hoc or locally-scoped naming systems by ensuring global uniqueness, which is essential for security (preventing spoofing) and for scalable service discovery across administrative and national boundaries.