IC-4BRV Hardware Description
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5.4 Description
The IC-4BRV interface card provides four ISDN Basic Rate Interface ports, together allowing up to 8
ISDN B-channels to work in parallel.
5.5 Operating
Modes
The four ports can be used in three different modes, which are tabulated in Table 5-2 below.
•
An X in the ’NET’ column of the table means that the port performs network side signaling
and that the pin out corresponds to an ISDN NT. A ’NET’ port is connected to an ISDN
terminal, i.e. a telephone or a PBX.
•
An X in the ’USR’ column means that the port performs user side signaling and the pin out
corresponds to an ISDN terminal. The two ports (2, 3) have configurable pin outs.
•
An X in the ’HW Bypass’ column refers to the fallback mode.
The possible BRI port configurations are listed in Table 5-2 below.
Port
NET
USR
HW Bypass
BRI 0
X
BRI 1
X
X
BRI 2
X
X
X
BRI 3
X
X
Table 5-2: BRI Port Configurations
5.6 Hardware
Bypass
BRI 1 and BRI 2 can be used to provide an emergency service. If a power failure occurs a relay
connects these two interfaces with each other.
•
BRI 2 must be connected to the ISDN network if the bypass is active.
•
BRI 1 must be connected with a telephone terminal or PBX if the bypass is active.
Calls from an ISDN terminal are then automatically connected to the LE of the ISDN network. The
bypass may also be activated manually. See the Software Configuration Guide document. Figure 5-2
shows a typical fallback situation when the bypass is activated: the numbers in the boxes refer to the
IC-4BRV’s four BRI port numbers.
Hardware Installation Guide, Revision 3.11
