This International Standardized Profile is applicable to interworking units concerned with operating in the Open Systems Interconnection (OSI) environment. It specifies a combination of OSI Base standards that collectively provide a Network Relay function for the connectionless-mode Network Service. This part of ISO/IEC ISP 10613 specifies media-dependent requirements which are applicable to an interworking unit attached to an ISO/IEC 9314 FDDI LAN subnetwork. The operation of an interworking unit may involve relaying from one subnetwork to another, and those subnetworks need not be of the saure type. This part of ISO/IEC ISP 10613 applies only to communication over those subnetworks which are FDDI LANs.