Troubleshooting and Maintenance
5-18
9161-A2-GH30-20
September 1997
Payload Loopback
The Payload Loopback (PLB) loops the information received on the Network or
DSX-1 interface back to the network after it has passed through the receive and
transmit framing section of the device. Use PLB for determining whether the
problem is with the T1 facility or in the circuitry of the remote device.
496-15198
Network
Interface
DSX
Port
All 1s
PLB
DCE
Port 1
DCE
Port 2
All 1s
All
1s
Framer
The following tests cannot be running when a payload loopback test is initiated:
Line Loopback or Repeater Loopback on the same Network or DSX-1
interface
Send Pattern Test on the same Network or DSX-1 interface or any data port
assigned to this interface
Send Remote Line Loopback on the same Network or DSX-1 interface
Send V.54 or Send FT1 Loopback on any data port assigned to this Network
or DSX-1 interface
Data Channel Loopback on any data port assigned to the same Network or
DSX-1 interface
CAUTION:
Payload Loopback may affect the operation of the FDL, DDL, or EDL.
Any IP data being sent while this test is active will be disrupted. Also,
any performance statistics being sent over the EDL will be disrupted.