CONTENTS

1 Procedures for the exchange of PAD control information and user data
1.3 Call user data
1.4 User sequences
1.5 PAD messages
2 User data transfer
3 Procedures for the use of PAD messages
3.1 Procedures for reading, setting, and reading and setting of PAD parameters
3.2 Procedures for inviting the PAD to clear
3.3 Interrupt and discard procedures
3.4 Procedure for resets
3.5 Error handling procedures by the PAD
3.6 Procedures for inviting the PAD to reselect the called DTE
3.7 Procedures for support of MAP
4 Formats
4.1 Introduction
4.2 Call user data format (see Figure 1)
4.3 User sequence format
4.4 Control message format
Annex A Characteristics of virtual calls and Recommendation X.25 as related to the PAD representation of a start-stop mode DTE to a packet mode DTE
A.1 General interface characteristics
A.2 Interface procedures for virtual call control
A.3 Interface procedures for data transfer
A.4 Virtual call characteristics