Cisco 2524 - Router - EN Overview page 5

Figure 1-5 4-Wire 56/64-kbps DSU/CSU WAN Module
4-WIRE
56K/64K
DSU/CSU
Figure 1-6 Fractional T1/T1 DSU/CSU WAN Module
MON
FTI/TI
DSU/CSU
IN
Captive
Monitor
screw
jack
LED
TX LB
CD
RX AL
Alarm
RJ-48S Carrier
LED
detect
LED
Receive
LED
JACK
OUT
NET
Carrier
RJ-48C
Overview of the Cisco 2524 and Cisco 2525 Routers 1-5
Captive
screw
Transmit
LED
Loopback
LED
TX LB
CD
RX AL
Alarm
LED
detect
LED
Receive
LED
Features
Captive
screw