1
Scope
2 References
3 Abbreviations
4 Reference configurations
4.1 Terminal adaptor reference model
4.2 Connection types
5 Line signals at S and T reference
points
5.1 Bit rate adaption of synchronous
data signalling rates up to 38.4 kbit/s
5.1.1 General approach
5.1.2 Adaption of V-series data signalling rates to the intermediate rates
5.1.3 Frame synchronization and additional signalling capacity
5.1.4 Adaption of intermediate rates to 64 kbit/s
5.2 Rate adaption of 48 and 56 kbit/s
synchronous user rates to 64 kbit/s
5.2.1 Frame synchronization
5.3 Adaption for asynchronous rates of up to 38
400 bit/s
5.3.1 General approach
5.3.2 Supported asynchronous user rates
5.3.3 Asynchronous-to-synchronous conversion (RA0)
5.3.4 Overspeed/underspeed
5.3.5 Break signal
5.3.6 Parity bits
5.4 Flow control for use with TAs
supporting asynchronous DTEs
5.4.1 Local flow control: between TA and DTE
5.4.2 End-to-end (TA-to-TA) flow control
5.4.3 Use of channel capacity
5.4.4 Requirements of a TA supporting flow control
6 Interchange circuits
6.1 Essential and optional interchange circuits
6.2 Timing arrangement
6.3 Circuit 106
6.4 Circuit 109
6.5 Electrical/mechanical
characteristics of interchange circuits
6.5.1 Basic ISDN user/network interface
6.5.2 TE2/TA (DTE/DCE) interface
6.6 Fault condition on interchange circuits
7 Operating sequence
7.1 TA duplex operation
7.1.1 Idle (or ready) state
7.1.2 Connect TA to line state
7.1.3 Data transfer state
7.1.4 Disconnect mode
7.1.5 Loss of frame synchronization
7.2 TA half-duplex operation
7.3 Automatic calling
8 Network-independent clocks
8.1 Measurement of phase differences
8.2 Positive/negative compensation
8.3 Encoding
9 In-band parameter exchange state
10 Testing facilities
Annex A – Reference configurations
A.1 Introduction
A.2 V.110 terminal adaptor reference model
A.3 Terminal adaption type
A.3.1 Terminal adaptor – Type A (TA-A)
A.3.2 Terminal adaptor – Type B (TA-B)
A.4 Types of end-to-end connection
Appendix I – In-band parameter exchange
I.1 Introduction
I.2 Definitions
I.3 Overview
I.4 Reference configuration
I.5 Procedures
I.5.1 General
I.5.2 Initiating the exchange
I.5.3 Parameter exchange
I.5.4 Re-synchronization to a new intermediate rate
I.5.5 Data transfer
I.5.6 Interworking with a TA not supporting IPE
I.5.7 Maintenance
I.5.8 Re-entering IPE from the data transfer state
I.5.9 Error protection and handling
I.6 Coding
I.6.1 General
I.6.2 Rate adaption version identification
I.6.3 Control
I.6.4 Parameters
I.6.5 Status
I.6.6 Maintenance
I.7 Timer values
I.7.1 Timer values for parameter exchange
I.7.2 Timer values for maintenance
I.8 State transition diagrams
I.8.1 General
Appendix II – V.25 bis
to Q.931 protocol mapping
II.1 General
II.2 Call origination
II.2.1 Call set-up
II.2.2 Call received from remote DTE/TA
II.3 Call clearing (Figures II.2 and
II.3)
II.3.1 DISCONNECT (from TA)
II.3.2 DISCONNECT (from exchange)
II.3.3 DISCONNECT (In-band between TAs)
II.3.4 RELEASE COMPLETE
II.3.5 Negative response to an incoming call
II.4 Direct call
II.4.1 Direct call DTE call set-up and clearing
II.4.2 Direct call DCE call set-up and clearing
II.5 Mapping of Q.931 causes to V.25 bis call failure indications and
responses
II.6 Additional information for handling of exception situations
II.6.1 Call collision
II.6.2 No channel available
II.6.3 Premature call
clearing