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You can set this option using Hayes command ATQ0;
-
Connect the SOPHO-LAM to the modem with the special cable described in appendix C.
3.2.
DATA COMMUNICATION OVER A DIGITAL ROUTE
Various types of Digital Trunk Units (DTUs) are used to connect ISPBX to the public network.
The different types are summarised in section
3.2.1. Data Terminal Connected to an ALC
A DTE can be connected to an ALC via a modem (see figure
to a Digital
Trunk.). The ALC samples and digitises the analogue signal from the modem
(modulated carrier) to a 64 kbps signal. The 64 kbps signal can be transferred to a DTU/DTX
via 2 Mbps links and the switching network. The DTU/DTX inserts the digitised signal into a
free timeslot in the digital trunk or tie-line. For full duplex communication the reversed path
must also be established.
V.24
MODEM
1
Modulated carrier.
2 Digitised modulated carrier in a 64kbps user channel.
2B+D, (DTU-BA or DTX-I) or 30B+D (other DTUs). B = user channel.
Figure 3-9 Analogue Connection to a Digital Trunk.
For an outgoing call the internal DTE must be allowed to dial the applicable trunk access code.
For an incoming call the external party must be allowed to dial the ALC-DNR. The connection
allowance between the compatibility value of the internal DTE and the compatibility value or
the trunk or tie-line must be set to allowed. The external DTE must use a compatible modem.
3.2.2.
Data Terminal Connected to a DLC/DTX
The data of an internal party is transferred between the DTE and a SOPHO-SET, SOPHO-
LAM or LAM via a V.24 or X.21 interface. The digital information is inserted in a user (B)
1
SN
IMP
DNR
64 kbps
CV
ALC
3.3. DIGITAL ROUTES
Figure 3-9 Analogue Connection
2
IMP
64 kbps
DTU/
DTX
Trunk
line
43
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