1
Scope
2 References
3 Definitions
4 Abbreviations
5 Overview of this Recommendation
6 Description of signals and
messages
6.1 Escape Signal (ES)
6.2 Mode Request (MR)
6.3 Capabilities Request (CR)
6.4 Mode Select (MS)
6.5 Capabilities List (CL)
6.6 Capabilities List Request (CLR)
6.7 Acknowledge Message (ACK)
6.8 Negative Acknowledge Message (NAK)
7 Structure of signals and messages
7.1 Signals
7.1.1 Frequencies
7.1.2 Duration
7.1.3 Tolerances
7.1.4 Transmitted power levels
7.2 Messages
7.2.1 Transmitted power level
7.2.2 Format convention
7.2.3 Frame structure
7.2.4 Preamble
7.2.5 Flag sequence
7.2.6 Information field
7.2.7 Frame check sequence field
7.2.8 Transparency
7.2.9 Invalid frames
8 Information field coding format
8.1 General
8.2 Coding format for parameters in the I and S fields
8.2.1 Parameter classification
8.2.2 Order of transmission of parameters
8.2.3 Delimiting and parsing of data blocks
8.3 Identification field (I)
8.3.1 Message type
8.3.2 Revision number
8.3.3 Parameter field
8.4 Standard information field (S)
8.4.1 ACK and NAK messages
8.4.2 MS, CL, and CLR messages
8.5 Non-standard information field
(NS)
8.6 Information field length
9
V.8 bis transactions
9.1 Permitted V.8 bis transactions
9.2 Transactions permitted at any time
on the PSTN and on leased point-to-point circuits
9.2.1 Transactions with no a priori
knowledge of V.8 bis support
9.2.2 Transactions with a priori
knowledge of V.8 bis capability
9.3 Transactions permitted only upon
automatic answering of a PSTN call
9.4 Use of escape signals
9.5 Use of the Negative Acknowledge
Message (NAK)
9.6 State transition diagrams
9.7 Suppression of ACK(1) after an MS
message
9.8 Error recovery
9.9 Procedures for initiating a modem
start-up after a V.8 bis transaction
9.9.1 V.8 start-up following a V.8 bis
transaction
9.9.2 Shortened V.8 start-up following a V.8 bis transaction
9.9.3 V.25 start-up following a V.8 bis
transaction
9.10 Message segmentation
10 Operating procedures
10.1 Operating procedures when not
automatically answering on the PSTN and on leased point-to-point circuits
10.1.1 Initiating station (MR or CR initiation)
10.1.2 Initiating station (MS, CL or CLR)
10.1.3 Responding station
10.2 Operating procedures upon
automatic answering of a call on the PSTN
10.2.1 Calling station
10.2.2 Answering station (MRe or CRe initiation)
10.2.3 Answering station (MS, CL or CLR initiation)11 DTE-DCE interface
Appendix I - Recommendation
V.8 bis features
I.1 Introduction
I.2 Basic features of this
Recommendation
I.3 Selection of a desired
communication mode
I.4 Identification of common operating
modes
I.5 Automatic selection between
terminals
I.6 User-friendly switching from
telephony to data
I.7 Conferencing applications
I.8 Interworking considerations
I.9 Relationship between ITU-T V.8 and
V.8 bis
Appendix II - Examples
of V.8 bis transactions
Appendix III - Effect
of echo suppressors
III.1 Introduction
III.2 Operation of echo suppressors
III.3 Dual tone signal breakthrough of
echo suppressors
III.4 V.8 bis transactions 4, 5 and 6
III.5 Automatic answering together with
a voice recording device
III.5.1 Blocking of V.8 bis
initiating signals
III.5.2 Blocking of response to MRe and CRe by OGM
III.6 Optional status of provisions