CONTENTS

1 Scope
2 References
3 Terms and definitionsd
4 Abbreviations
5 General
5.1 Encapsulation function location
5.2 Basic features
5.3 Use of X.75 for PDN interconnection
5.4 Protocol stack on the local interface
6 Call Set-up procedures
6.1 General
6.2 Call set-up conditions
6.3 Coding of the call request packet
6.4 Reception of the incoming call packet
6.5 Coding of the call accepted packet
6.6 Reception of the call connected packet
6.7 Negotiation at call set-up
6.8 Call set-up collision
7 Call clearing procedures
8 Data Transfer procedure
8.1 Reception of PDU from the local interface
8.2 Encapsulation format
8.3 Data transfer on the X.25 virtual call on the network side
8.4 Flow control
9 Encapsulation of Frame Relay
9.1 General Principles
9.2 Procedures for Frame Relay permanent virtual circuit
9.3 Procedures for switched virtual call
9.4 FR frames transfer procedure
10 Encapsulation of IP datagrams
10.1 General Principles
10.2 Call set-up procedures
10.3 Call clearing procedures
10.4 IP datagrams transfer procedure
10.5 Flow control
Annex A Protocol Implementation Conformance Statement (PICS) proforma
A.1 Instructions for completing the PICS proforma
A.2 Identification
A.3 Claimed Conformance to standards
A.4 Call set-up procedures
A.5 Call clearing procedures
A.6 Data transfer procedures
A.7 Encapsulation of Frame Relay
A.8 Encapsulation of IP datagrams
A.9 Other information
Annex B Coding of clearing cause and diagnostic fields generated by an encapsulation function in clear request packet
Appendix I Application examples
I.1 Dynamic negotiation of the encapsulated protocol
I.2 X.25 DTE / X.36 DTE interworking for a given encapsulated protocol
I.3 X.25 DTE / X.36 DTE interworking for multi-protocol encapsulation
Appendix II Technical discussion
II.1 Mode of operation for the multi-PDU transfer
II.2 Flow control
II.3 Flow control for the FR case
Appendix III Protocol identification mechanism for data packets when the Q-bit is used