Rear Panel; Isdn Connection; Figure 1-7. Express L128T S/T Rear Panel - ADTRAN Express L128T S User Manual

Chapter 1. Understanding ISDN and the Express L128T S/T

Rear Panel

The Express L128T S/T has one RJ-45 jack, labeled ISDN, on the rear
panel for network connection (see Figure 1-7). There are two sets of
switches on the back panel. The TO HUB/TO NIC switch allows the
Express L128T S/T to connect directly to a Network Interface Card
(NIC) or a HUB without the need for special cabling. The OFF/ON
switch block is for factory default, firmware downloading, S/T bus
termination, and A-LAW/µ-LAW Pots tone selection. With switch 1
in the up or OFF position, the L128T S/T will go immediately into a
download mode when power is enabled. Switch 1 must be in the
down or ON postition in order to boot up normally. Switch 2 in the up
or OFF position will force the entire configuration to be factory de-
faulted. Switch 3 must be up or in the OFF position to disable passive
bus (enable 100 π termination). Switch 4 must be up or in the OFF po-
sition to disable µ-Law (enable A-LAW).
TO TO
HUB NIC
1
OFF
ON
1 2 3 4
2 1 ISDN
POWER O 10 BASE T EIA232
1202070L3

Figure 1-7. Express L128T S/T Rear Panel

ISDN Connection

From the network, ISDN is delivered by a single 4-wire S/T interface
which is connected directly to the Express L128T S/T. 100 ohm termi-
nation resistors can be enabled for point-to-point application and dis-
abled for passive bus applications via a dip switch on the rear panel.
The Express L128T S/T has one RJ-45 jack, labeled ISDN, on the rear
panel for network connection (see Figure 1-7). ISDN basic rate service
divides a standard telephone line into three digital channels capable
of simultaneous voice and data transmission. The three channels are
comprised of two bearer (B) channels at 64 kbps and one Delta (D) or
Signalling channel at 16 kbps, known as 2B+D.
1-12 Express L128T S/T User Manual 61202070L3-20