DEFINITY ECS Release 8.2 Maintenance for R8.2csi
555-233-119 Issue 1
April 2000
Maintenance for csi systems
1-76Install DS1 CPE Loopback Jack (T1 Only)
1
b. The DS1 cannot frame on the incoming span ’s signal after the
loopback jac k is powered down. This means that there is
something wrong with the receive si gnal into the loopbac k jack from
the “dumb” block or the Smart Jack. If the ser vice provider
successfully looped and tested the span , up to the Smart Jack, this
condition isolates the prob lem to the wiring between the lo opback
jack and the Smart Jack. Refer to ‘‘Loopback Jack F ault Isolation
Procedures’’ for information on how to proceed in this case. The
test cannot be succ essfully terminated until a g ood signal is
received. To properly terminate the test befo re a good receive
signal is available, enter reset board <location>.
12. Restore the TX LBO field to the original value record ed in Step 2.
13. Release the DS1 circuit pack using the release board PCSSpp
command.
14. Leave the loopback jac k connected to the DS1 span.
Loopback Jack Fault Isolation Procedures
This section describes the possible DS1 configu rations in which the loopb ack
jack may be used. These co nfigurations are: when the DS1 provider inc ludes a
Smart Jack, when no Smart Jack is provid ed at all, and when sites use fib er
multiplexers.
Configurations Using a Smart Jack
The addition of the loopba ck jack and the p resence of a Smart Jack divid es the
DS1 span into 3 separate sections for fault is olation. These sections are shown in
Figure 1-21 through Figure 1-23 for the different sp an configurations. They are:
A problem can exist in 1 or m ore of the 3 sections. The field technic ian is
responsible for finding and correcting problems in the first 2 sec tions. The DS1
service provider is resp onsible for finding an d correcting p roblems in the third
section. Testing is divided into 3 steps.
■Test customer premises wiring (section 1 in the following 3 figures) from
the ICSU to the loopback jack as described in “DS1 Span Test.”
■Test the CO-to-network interface wiring (section 3 in Figure 1-21) using the
Smart Jack loopback (CO responsibility). Coordinate thi s test with the DS1
provider.
Section 1: Between the 120A2 (or later) ICSU and the loopb ack jack.
Section 2: Between the loopback ja ck and the Smart Jack (network
interface point).
Section 3: From the Smart Jack to the CO. It is necessary to contac t
the DS1 provider to run this test.