Extreme Networks WM-4T1i - Manual (Page 23)

WM-4T1i Module Installation and User Guide 2-9
Monitoring T1 Physical Link
The remote line mode reflects the received signal back to the near-end. The remote
payload mode reflects the data and regenerates the framing information back to the
near-end.
Figure 2-5: Remote line loopback mode
Remote Line Loopback Mode. When the local port is enabled for remote line
loopback mode, it sends a request to the remote end to enter the equivalent of network
line loopback mode. The signal transmitted to the remote end will be retransmitted as
received back to the local end.
Note: If the line is configured to use the ATT FDL standard, the remote end must
be configured to detect inband loopback requests for the remote end to enter
remote line loopback mode.
Figure 2-6: Remote payload loopback mode
Remote Payload Loopback Mode. When the local port is enabled for remote payload
loopback mode, it sends a request to the remote end to enter the equivalent of network
payload loopback mode. When the remote end enters loopback mode, the framer at the
XM_014
Remote T1 Port Local T1 Port
Framer
Data in
Data out
Data out
Data in
Framer
XM_015
Local T1 Port Remote T1 Port
Framer
Data in
Data out
Data out
Data in
Framer