1 Introduction
2
References
3
Definitions
4
Abbreviations
5
Line signals
5.1 Carrier frequency and modulation rate
5.2 Transmitted spectrum
5.3 Audio frames
5.4 Data-only coding
5.5 Audio plus data coding
5.6 Control segment encoding
5.7 Multiplexing/demultiplexing of data and control segments
6
Interfaces
6.1 DTE interface
6.2 Audio interface
7
Scrambler and descrambler
7.1 Scrambler/descrambler allocation
8
Operating procedures
8.1 Call establishment, capabilities exchange, and mode selection
procedures
8.2 V.25 automatic answering sequence
8.3 Symbol rate determination signal
8.4 Channel holding signal
8.5 Round trip delay estimating signals
8.6 Receiver conditioning signal
8.7 Rate signal
9
Start-up procedure
9.1 Call mode modem
9.2 Answer mode modem
10 Retrain procedure
10.1 Call mode modem
10.2 Answer mode modem
10.3 Operation of circuits 107 and 109 during retrain procedure
11 Rate renegotiating procedure
11.1 Initiating procedure
11.2 Responding procedure
12 Testing facilities