Configuring the T1 Physical Link
Local T1 Port
Data in
Data out
Framer
Figure 2-3: Network line loopback mode
Remote T1 Port
Framer
Data out
Data in
XM_012
Network Line Loopback Mode. When the local port is enabled for network line loopback mode, the received signal is sent back to the remote end without reframing the data. This mode primarily tests the integrity of the line from the remote side.
Local T1 Port
Data in
Data out
Framer
Figure 2-4: Network payload loopback mode
Remote T1 Port
Framer
Data out
Data in
XM_013
Network Payload Loopback Mode. When the local port is enabled for network payload mode, the framer removes the framing bits from the received signal and recovers the transmitted data. This same data is then reframed and transmitted back to the remote end. This mode tests the line and the local circuitry from the remote side.
Far-End Loopback Modes
The
•Remote Line
•Remote Payload
