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DS0 DIAGNOSTICS
DS0 Circuit Delay
Measurement Test
The DS0 diagnostics described below include channel-level diagnostic
tests that affect a single channel, or a DS0 (Digital Signal Level 0). Use
these tests when you suspect that a problem is impairing data only on an
isolated channel. Only one test, on one of the 24 channels, can be per-
formed at a time. A DS0 diagnostic affects only the selected channel.
These tests can be controlled only via the Supervisory terminal.
All DS0 diagnostic functions for the remote CSU must
be controlled using only out-of-band communications.
a. You cannot initiate a DS0 diagnostic while a DS1
diagnostic is in progress.
b. In Unframed Mode, the entire bandwidth is cus-
tomer payload, so the signal is not channelized and
DS0s do not exist. For this reason, there are no
channel-level
Diagnostics selection is removed from the MAIN
MENU. You cannot perform the DS0 Circuit Delay
Measurement Test, DS0 End-to-End Self-Test, DS0
Remote Test, or DS0 Remote Test with Self-Test.
DS0 Circuit Delay Measurement Test, illustrated in Figure 4-16, computes
the round trip (from the local CSU to the remote CSU and back) transmis-
sion delay for the selected channel, using an internally-generated
sage. Transmission delay includes many variables, such as circuit dis-
tance, transmission path (terrestrial vs. satellite, primary vs. alternate
route), etc. For this reason, no absolute figures of acceptable delay are
given here. Use the test result as an indication of network response time
and throughput, and compare it to the result of the same test repeated at
other times under similar conditions.
To perform this test, refer to Table 4-10.
TABLE 4-10. DS0 CIRCUIT DELAY MEASUREMENT TEST
Step
1.
To prevent data loss, suspend operation of all associated digital-terminating
equipment on the channel to be tested.
2.
At the remote CSU, select the desired channel, select LOOPBACK mode, and
then initiate the test (all on the DS0 DIAGNOSTICS screen). The status line
DS0LB indicator should come on.
3.
At the local CSU, select the same channel, select DELAY TEST mode, and
then initiate the test (all on the DS0 DIAGNOSTICS screen).
4.
At the local CSU, the delay (in ms) is displayed in the Circuit Delay result field.
The local CSU automatically stops its test.
5.
To stop the test, terminate LOOPBACK at the remote CSU.
CAUTION
NOTE
(DS0)
diagnostics
Supervisory Terminal Control
TESTS
and
the
DS0
mes-
4-19
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