How Fritz!Card Pci Works; Fritz!Card Pci On The Isdn Line - AVM FRITZ!Card PCI Installation Manual

How FRITZ!Card PCI Works

5 How FRITZ!Card PCI Works
This chapter provides basic information about FRITZ!Card PCI
on the ISDN line and the way an ISDN-Controller functions.

5.1 FRITZ!Card PCI on the ISDN Line

When your ISDN access is configured, the ISDN provider in-
stalls a network terminator (NT) first. An NT usually is
equipped with two ISDN sockets, each of which is an exter-
nal S interface.
0
In most cases an ISDN PBX with analog extensions is con-
nected to one ISDN socket of the NT and a digital terminal
device to the other: in this case, the ISDN-Controller. Analog
terminal devices such as telephones, answering machines
and G3 fax machines are connected to the PBX extensions.
The connected devices are addressed through distinct tele-
phone numbers. These telephone numbers are referred to in
the terminology of ISDN as Multiple Subscriber Numbers
(MSNs). Each ISDN line is equipped with several MSNs.
If a PBX is connected to one of the ISDN sockets and your
computer with FRITZ!Card PCI to the other, additional ISDN
sockets are required to connect any other ISDN terminal de-
vices like an ISDN telephone (see the gray area in the figure
below).
FRITZ!Card PCI – 5 How FRITZ!Card PCI Works 35