Paradyne 7511 User Manual

Testing4-37511-A2-GB20-00 June 1997Digital Loopback (DL) and Remote Loopback (RL)A Digital Loopback is an internal loopback that loops the signal received on thenetwork interface back to the network. This loopback can be initiated on a remoteDSU by initiating a Remote Loopback test, which sends the V.54 Loop Upcommand to the remote unit.Remote loopback in a multipoint environment is restricted to one tributary DSU ata time. The other tributary DSU must be turned off or otherwise disabled. ProcedureTo run a Digital Loopback or Remote Loopback:1. Select the DSU you wish to test using the A/B switch.2. Determine that no test is active by checking the TEST LED. If a test is active,wait for it to end, or press the Test Mode switch once to abort the test. TheTest Mode switch will not terminate a DTE- or network-initiated loopback.3. When the TEST LED is off, press the Test Mode switch— Two times for a Digital Loopback (DL) test— Three times for a Remote Digital Loopback (RL) testThe appropriate LED (DL or RL) lights up.4. Wait three seconds. The TEST LED lights up and the test begins.(If the TEST LED never lights up and the RL LED turns off, the V.54 Loop Upcommand was not acknowledged by the remote unit.)DSU CSUDTEInterfaceAggregateDTEPortDDSNetworkPort496-15160DSU Loopback