System information

BSR 64000 Configuration and Management Guide
14-20
Specifying the POS Loopback Mode Type
You can use POS loopback commands to isolate the fault on an end-to-end circuit,
especially when the circuit is down.
Table 14-8 describes the POS loopback mode command:
Follow these steps to specify the POS loopback mode:
1. To specify that the data transmitted out of the SONET framer device is directly
looped to the receive side of the SONET framer device, use the loop internal
command in Interface Configuration mode, as shown below:
MOT(config-if)#loop internal
2. To specify the line loopback mode, which is used to connect the received SONET
network signal directly to the transmitted SONET network signal, use the loop
line command in Interface Configuration mode, as shown below:
MOT(config-if)#loop line
3. To specify that the data transmitted out of the SONET transceiver device is
directly looped to the receive side of the SONET transceiver device, use the loop
txrx-line command in Interface Configuration mode as shown below:
MOT(config-if)#loop txrx-line
Table 14-8 SONET Signal Mode Command
Command Description Default Value
pos loop POS loopback mode type none internal, line,
txrx-line,
txpos-rxpos
Note: When configured in line loop mode, the BSR never receives data from
the network. Use the no loop command to clear any loopbacks.