Using Loopbacks
181
OC3/STM-1 Loopbacks
The following loopbacks are available for the OC3/STM-1 interface:
Network LIne
—Loops the OC3/STM-1 received data back on the output side
after the digital data has been recovered.
Local Card
—Loops the transmit OC3/STM-1 output on the receive side; the
transmitted data will continue to go on the output.
Figure 139 illustrates the loopbacks for OC3/STM-1.
Figure 139
OC3/STM-1 Loopbacks
DS3 Loopbacks
The DS3 module supports the following loopbacks:
Local Card
—Loops the transmit DS3output on the receive side. All cells coming
from the DS3 card are looped through the backplane and back to the DS3 card.
The transmitted data will continue to go on the output.
Network Line
—Loops the DS3 received data back on the output side after the
digital data has been recovered.
Network Card
—Loops the DS3 received cell payload back toward the line output.
Figure 140 illustrates the DS3 loopback options.
Figure 140
DS3 UNI Loopback Options
Local Card
Payload
Network Line
Network Side
OC3 Interface
DS3 Interface
Network Side
Local Card
Network
Line
Network Card
Bus Side
