Verilink C100 (880-502893-001) Product Manual - Manual (Page 45)

LED Indicators and Diagnostics
6/15/99 C100 and C150 T1/FT1 CSU/DSU 4-5
Loopbacks and diagnostics LEDs
Loopbacks are labeled Local and Remote on the C100. On the C150
they are labeled LCL LOOPS and REM LOOPS. The C150 has DSX
loopback LEDs in addition to the C100 loopback LEDs. See the front
panel illustrations below.
Local Network
Interface (NI)
Loopback The Local Network Interface (NI) LOOPBACK LED is on solid when it
is selected by the Select push-button. When the Local NI LOOPBACK
LED blinks at a fast rate, the T-1 CSU/DSU has the Network Interface
looped back onto itself (see circled loop in
Figure 4-3 a.) and was
activated locally. When the Local NI Loopback LED blinks at a slow
rate the T-1 CSU/DSU has the Network Interface looped back to the
Network (see circled loop i
Figure 4-3 b.) and was activated by the
carrier provider or the remote unit. The color of this LED is red.
Illustrations of examples of the C150 follow those of the C100. These
example show PBXs connected by a DSX-1 line.
C100 examples
Figure 4-3 C100 T-1 CSU/DSU in Local NI Loopback
Pattern
Checker
Pattern
Checker
Pattern
Generator
Pattern
Generator
T-1 CSU
T-1 CSU
Channel
Channel
Remote T-1 CSU/DSU
Remote T-1 CSU/DSU
Pattern
Checker
Pattern
Checker
Pattern
Generator
Pattern
Generator
T-1 CSU
T-1 CSU
Channel
Channel
Local T-1 CSU/DSU
Local T-1 CSU/DSU
Bridge
Bridge
Bridge
Bridge
NI
NI
NI
NI
NETWORK
NETWORK
Figure 4-2b. T-1 CSU/DSU in Local NI Loopback (CSU Loopback from the Network):
Figure 4-2a:
Router Router
Router
Router