CONTENTS

1 Introduction
2 Circuit witched data transmission service
3 Packet switched data transmission services
3.1 Direct access to a packet switched data transmission service
3.2 Port access to a packet switched data transmission service (user classes of service 20-26 and 29)
3.3 Port access to a packet switched data transmission service (user classes of service 8-12, 26 and 30)
3.4 Additional capabilities provided by multicast service
4 Frame relay data transmission service
4.1 Direct access to a frame relay data transmission service
4.2 Port access to a frame relay data transmission service
5 Leased circuit data transmission service
Appendix I  Coding of optional user facilities
II.1 Introduction
II.2 Independent operation
II.3 Minimum relationship
II.4 Maximum relationship
II.5 Summary