scope:

This International Standard provides an architectural model of the OSI Network Layer as a framework for OSI Network Layer standardization, allowing incorporation of existing networks within the OSI architecture. This framework encourages the design of real subnetworks that fully support the OSI Network Service whilst accommodating the participaton, in the OSI environment, of other subnetworks that do not fully support the OSI Network Service. This International Standard is intended for use both in the design and application of Network Layer protocols, operating between network-entities either in end systems providing the OSI Network Service, or in intermediate systems providing the routeing and relay functions.