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TESTS
DS1 Remote Test
with Self-Test
4-14
DS1 Remote Test with Self-Test activates the remote CSU's DS1 Line
Loopback function (illustrated in Figure 4-12) or DS1 Test Loopback func-
tion (Figure 4-13), depending on which one is enabled in the remote CSU.
This tests both CSUs and the T1 link by transmitting a local CSU-gener-
ated test pattern to the remote CSU and looping it back for verification.
The test pattern is selected via option switch S5-4 or the Supervisory ter-
minal. Within the local CSU, a Test Pattern Generator creates the test
pattern, and a Test Pattern Recognizer determines if the data it receives
matches that which was transmitted. Bipolar violations are not corrected
during this test when the remote CSU has its LLB function enabled.
Whether the local CSU transmits framed or unframed loopback codes de-
pends on the selection of the loopback test code framing option.
This test can be controlled locally via front panel switches RT and ST, or
the Supervisory terminal Remote Test and Self-Test. To perform this test,
refer to Table 4-7.
Initiating DS1 Remote Test with Self-Test causes the lo-
cal CSU to send the loopback code and test pattern to
the remote CSU, and to reflect the local CSU's test status
via its front panel and status line indicators. These indi-
cators do not imply that the remote CSU is in loop-
back, as the remote CSU does not acknowledge receipt
of loopback codes nor does it inform the local CSU of
its test status. Inband Loopback Code Detection must be
enabled in the remote CSU.
TABLE 4-7. DS1 REMOTE TEST WITH SELF-TEST
Step
Front Panel Control
1.
To prevent data loss, suspend operation of all associated digital-terminating
equipment.
2.
Engage the local CSU's RT and ST
switches. The TM indicator should be
lit during the test.
3.
Monitor the ERR/ALM indicator. If it
blinks, a problem exists.
4.
To stop the test, disengage the ST
and RT switches.
NOTE
Supervisory Terminal Control
Initiate Remote Test at the local CSU
(on the LOOPBACKS screen) and then
Self-Test (on the SELF TEST screen).
Monitor Test Results for the averaged
BER. A high BER indicates that a
problem exists.
To stop the test, terminate Self-Test
and then Remote Test.
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