AS 3622-1989

1 - AS 3622-1989 INFORMATION PROCESSING SYSTEMS-OPEN SYSTEMS INTERCONNECTION-INTERNAL ORGANIZATION OF THE NETWORK LAYER
4 - PREFACE
6 - Contents
7 - 0 Introduction
7 - 1 Scope and field of application
8 - 2 References
8 - 3 Definitions
8 - 3.1 Reference model definitions
8 - 3.2 Service conventions definitions
8 - 3.3 Network Layer architecture definitions
9 - 4 Abbreviations
9 - 5 Network Layer concepts and terminology
9 - 5.1 Real world objects and abstract elements
9 - 5.2 End Systems and intermediate systems
9 - 5.2.1 End system considerations
9 - 5.2.2 Intermediate system considerations
9 - 5.3 Real subnetworks and subnetworks
11 - 5.4 Relay systems and interworking units
11 - 5.5 Data transmission service and subnetwork service
11 - 5.6 Service types
11 - 6 Organization of the Network Layer
16 - 6.1 Factors which influence the Internal organization of the Network Layer
16 - 6.2 Description of the possible roles for a Network Layer protocol
17 - 6.3 Subnetwork access protocols
17 - 6.4 Subnetwork independent convergence protocols
17 - 6.5 Subnetwork dependent convergence protocols
17 - 6.5.1 Relationship of SNDCP to SNICP
17 - 6.5.2 Relationship of SNDCP to the OSI Network Service
17 - 6.6 Relaying and routeing
18 - 6.7 Single Network Layer protocol fulfilling all protocol roles
18 - 7 Application of the Network Layer internal organization
18 - 7.1 Interconnection of subnetworks supporting all elements of the OSI Network Service
18 - 7.2 Hop-by-hop harmonization
18 - 7.3 Use of an internetworking protocol approach
19 - 7.4 Combinations of approaches for interconnecting subnetworks
19 - 8 Interconnection scenarios
19 - 8.1 Single data-link/single subnetwork inter-connection
20 - 8.2 Interconnections involving subnetworks which support all elements of the Network Service
20 - 8.3 Interconnections involving multiple protocol combinations

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 participation, in the OSI environment, of other subnetworks that do not fully support the OSI Network Service. This Standard is identical to and has been reproduced from ISO 8648:1988.

This International Standard provides an architectural model of the OSI Network Layer as a framework tor OSI Network Layer standardization, allowing incorporation of existing networks within the OSI architecture.This framework encourages the design of real sub-networks that fully support the OSI Network Service whilst accommodating the participation, 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.It shall be used toa) provide a common set of concepts and terminology for use in Network Layer standards (such standards shall reference this International Standard);b) analyseNetworkLayer functionalityand classify Network Layer protocols;c) specify how "real networks" should be used in supporting or providing the OSI Network Service, in particular, in circumstances where multiple "real networks" are to be interconnected and used.The organization defined herein does not address Network Layer management; in particular it is not concerned with the relationships among Network Layer entities which may be required for Network Layer management purposes. In addition, this International Standard does not specify the operational requirementsfor relay functionsin intermediate systems, nor address how specific combinations of permitted functions might be practically and efficiently utilized.