CONTENTS

�0���� Introduction��������� iii
�1���� Scope and field of application
�2���� References
�3���� Definitions
������� 3.1���� Terminology defined in other Recommendations
������� 3.2���� Terminology defined in this Recommendation
������� 3.3���� Graphical conventions
�4���� Abbreviations
�5���� Networks to be interconnected and data transmission services to be offered
������� 5.1���� Packet Switched Public Data Network (PSPDN)
������� 5.2���� Circuit Switched Public Data Network (CSPDN)
������� 5.3���� Frame Relay Public Data Network (FRPDN)
������� 5.4���� Integrated Services Digital Network (ISDN)
������� 5.5���� Public Switched Telephone Network (PSTN)
������� 5.6���� Common Channel Signalling Network (CCSN)
������� 5.7���� Public mobile systems
������� 5.8���� Private networks
�6���� Principles for interworking involving transmission capabilities only
������� 6.1���� Composition and decomposition of subnetworks
������� 6.2���� Categories of interworking
������� 6.3���� Categorization of subnetworks with respect to the support of the OSI-NS
������� 6.4���� Relationships with respect to management
������� 6.5���� Basic principles in relation with service indication parameters
�7���� Principles interworking involving both transmission and communication capabilities
������� 7.1���� Composition and decomposition of application relay systems
������� 7.2���� Categories of interworking
������� 7.3���� Identification of application relay system types
������� 7.4���� Relation between application IWF, networks and application relay system types
������� 7.5���� Interconnection of application relay system types
������� 7.6���� Use of application relay system types
������� 7.7���� Relationships with respect to management
������� 7.8���� Relationships with the Reference Model of OSI for ITU-T applications
������� 7.9���� Basic principles in relation with service indication parameters
�8���� Description of the different interworking conditions
������� 8.1���� General
������� 8.2���� Interworking via a non-OSI adapter between PSTN and PSPDN
������� 8.3���� Interworking involving ISDN for the provision of datatransmission services
Annex A � Basic categories of subnetworks
������� A.1���� Type I subnetwork
������� A.2���� Type II subnetwork
������� A.3���� Type III subnetwork
� ������A.4���� Type IV subnetwork
Annex B � Examples of subnetwork compositions
������� B.1���� Examples of Type I and Type II interconnection
������� B.2���� Type I � Type III interconnection
������� B.3���� Type II � Type III interconnection
������� B.4� ���Type IV � Type I interconnection