Connection between the network and the customers premises is by synchronous
dataline. The type of dataline will depend on the speed and type of service
required.
The following types of connection are available:
Speed | Type | Interface |
2400 bps | analogue | v.24 |
9600 bps | analogue | v.24 |
48000 bps | kilostream | V.11 or V.35 |
64000 bps | kilostream | V.11 |
Customers Terminal Equipment must conform to Designation No 89/018S under the
Telecommunication Act 1984. (see NET2).
Customers equipment must conform to the electrical interface requirements of
the appropriate modem or NTU. In general the following interchange circuits
are used:
Configuration and Troubleshooting information
The physical link should remain permanently established, If the user does not
wish to make or receive calls this can be signalled by layers 2 and 3 of the
protocol (explained later on this document).
Therefore the following circuits should remain permanently ON: RTS, CTS, DSR
and DTR.
Transmit and Receive data circuits will continuously send FLAGS (binary value
= 01111110) when no frames are being transmitted.
Transmit and Receive Clock circuits, will be used as specified below.
In case of problems, the user should ensure that their equipment is transmitting the correct signals. If RFS, DSR and CD are OFF or clocks and flags are not being received then the dataline may be faulty.
¬es& = yTemporary notes for reviewers
I need to get Chris Wakely to check the modem information (or get a copy of the modem guides myself).
v.24 Interface
Standards:
Mechanical Characteristics: ISO 2110
Electrical Characteristics: V.28,ISO 7498
Functional Characteristics: V.24,RS232,X.21 bis
Procedural Characteristics: X.25 level 2
Maximum cable length between modem and computer: 15 Metres
103 - Transmitted data - From DTE
104 - Received Data - To DTE
105 - Request to send - The DTE should normally maintain this
circuit in the ON conditions.
106 - Ready for Sending - The DCE normally maintains this
circuit ON to signal that data can be
sent on 103.
107 - Data Set Ready - The DCE normally maintains this
circuit ON to signal that data can be
transmitted and received.
108 - CDSL/DTE - The DTE should maintain this circuit ON.
109 - Carrier Detect - The DTE should monitor this circuit and
received data should be ignored if 109
is OFF.
113/114 - TSET - Transmit Clock, options,
a) TSET derived from RSET - recommended
b) DTE independently generate - may be
possible on some modems
c) DCE independently generate TSET - may be
possible on some modems
115 - RSET - Receive clock, Provided by DCE.
&internal&=y
4.2 - rs449 Interface
Standards:
Mechanical Characteristics: ISO 4902,ISO 4903
Electrical Characteristics:
Functional Characteristics:
Procedural Characteristics:
Maximum cable length between modem and computer:
4.2 - V.35 Interface
Standards:
Mechanical Characteristics:
Electrical Characteristics:
Functional Characteristics:
Procedural Characteristics:
Maximum cable length between modem and computer:
4.3 - V.11 Interface
Standards:
Mechanical Characteristics:
Electrical Characteristics: V.11,X.27,RS-422A
Functional Characteristics: X.21
Procedural Characteristics:
Maximum cable length between modem and computer: