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Operating the DSU
Manual Backup
You can control each step of a backup attempt by following one of these procedures.
Placing a Backup Call
To place a backup call:
.Procedure
1.Go to the Bkup option set under the Confg branch and set Auto Bckup to Disab.
2.Select Bckup (Backup branch) to select a telephone number from the Backup Directory.
3.Select Dial, the Backup Dir screen is displayed identifying the Backup Directory indicator.
If the telephone number in the Backup Directory is the number you want to dial, go to Step 5.
4.Select another telephone number to call:
•Press the F1 key ( ↑ ) to increment the directory indicator (e.g., 1 to 2).
•Press the F2 key ( ↓) to decrement the indicator (e.g., 2 to 1).
5.Select Dial (F2); the DBM places the call.
6.Once the dialed call has been established, select !Cnnct to switch data to the dialed connection.
Manual Dial Backup Termination
•If in Standby mode, select Disc.
•If in Dial Backup mode, select DrBU.
Test Branch
The Test branch provides extensive testing capabilities for the DSU, the DDS circuit, the DBM, and the backup circuit. Most tests can be run simultaneously on the DSU and DBM. When the tributary DSU receives a test request from the control DSU, it aborts any locally initiated test in progress.
Running a test can affect your application data or may cause your application session to be dropped depending upon
Abort
The Abort selection allows you to abort a test that is running. The DSU cannot run any other test until the test in progress is aborted.
There are two types of selections to abort a test:
•Selective terminates whatever test is in progress at the local DSU.
•Subn (Subnetwork) only displays for the DBM branch. This selection terminates all tests running on the remote DSU or DBM.
After selecting either Selective or Subn, the test is terminated and the DCP displays the message Command Complete.
Device Test
The Device (Devic) Test uses a test pattern generator built into the DSU. When testing the DBM, the DBM must be in Idle mode, with no call in progress before running a Device Test.
NOTE
On
Loopback
The Loopback (Lpbk) branch displays four loopbacks:
•Local Loopback (LL) ± DSU only
•DTE Loopback (DTE)
•Digital Loopback (DL)
•Remote Digital Loopback (RL) ± DBM only
Figure 4-3 shows where each loopback occurs on the circuit. Refer to the figure as you read about loopbacks.
December 1996 |