1
Scope
2 Normative references
3 Definitions and conventions
4 Abbreviations
5 Terminal capabilities
5.1 Audio capabilities
5.2 Video capabilities
5.3 Transfer rate capabilities
5.4 Data capabilities
5.5 Terminals on restricted networks:
capability
5.6 Encryption and extension-BAS
capabilities
5.7 Null capability
6 Transmission
6.1 Transmission modes
6.2 Establishment of compatible modes
of operation
7 Frame structure
8 Basic sequences for in-channel
procedures
8.1 Capability exchange sequence A
8.2 Mode switching sequence B
8.3 Frame reinstatement sequence C
9 Mode initialization, dynamic mode
switching and Mode 0 forcing
9.1 Mode initialization procedure
9.2 Dynamic mode switching (see Figure
2)
9.3 Mode 0 forcing procedure
9.4 Mode mismatch recovery procedure
9.5 Procedure for influencing the mode
transmitted from remote endpoint
10 Recovery from fault conditions
10.1 Unexpected loss of synchronization
or frame alignment
10.2 Recovery from loss of
connection(s)
11 Network consideration: call connection, disconnection and call transfer
11.1 Call connection
11.2 Terminal disconnection
11.3 Call transfer
11.4 Conferencing
12 Procedure for activation and de-activation of data channels
12.1 General
12.2 Procedures applicable to all data
types
12.3 Equipment capable of operating
using protocol according to ITU-T Rec. T.120
12.4 Data equipment not conforming to
ITU-T Rec. T.120
12.5 Dummy data
13 Procedures for operation in restricted networks
13.1 Network aspects
13.2 Terminal-network configurations
and properties
13.3 Transmission formats
13.4 Procedures
14 Procedure for use of BAS-extension codes
15 Bit occupancy and the sequencing of BAS codes
16 Procedure for dealing with single/multiple channel interconnection
17 Procedure for use of encryption control signal channel
18 Transmission of network addresses
18.1 Address of initial connection
18.2 Addresses of additional
connections
19 Informative codes
19.1 Recommendation version identification
19.2 Manufacturer/type identification
Appendix I –
Initialization: Case of videophone to
ITU-T Rec. H.320, type Xb
Appendix II – Mode-0
forcing: Case of videophone to ITU-T
Rec. H.320, type Xb
Appendix III –
Example of use of message structure
III.1 Initial capability exchange,
including MBE-cap
III.2 Subsequent capability exchange,
including MBE capability message
III.3 Mode switch to non-standard mode
using MBE command
Appendix IV –
Examples of symmetrical and asymmetrical transmission modes
IV.1 Example of symmetrical
transmission mode
IV.2 Example of asymmetrical
transmission mode
IV.3 Example of unsymmetrical video
mode
Appendix V – Examples
relating to data transmissions
V.1 Transfer-rate 1B, audio at 48
kbit/s, no video or video off
V.2 Transfer-rate 1B, audio at 16
kbit/s, no video or video off
V.3 Transfer-rate 1B, audio at 16
kbit/s, video on
V.4 Transfer-rate 2B, audio at 48
kbit/s, video on
V.5 Transfer-rate 2B, audio at 16
kbit/s, video on
Appendix
VI – Hierarchical capability BAS codes
Appendix VII –
Interpretation of received audio capability BAS codes
Appendix VIII –
Examples of legal and illegal capability BAS sequences
Appendix IX
Appendix X – An
algorithm to determine whether an incoming bit
stream was encoded by m-law or A-law PCM
X.1 Basic determination algorithm
X.2 Possible
extensions and refinements