Configuring DS1 using a Smart Jack

Last Updated : Apr 28, 2014 |

About this task

The addition of the loopback jack and the presence of a Smart Jack divides the DS1 span into three separate sections for fault isolation. A problem can exist in one or more of the three sections. The field technician is responsible for finding and correcting problems in the first two sections. The DS1 service provider is responsible for finding and correcting problems in the third section.

Testing is divided into three steps:

Procedure

  1. Test customer premises wiring (Span Section 1 in the following three figures) from the ICSU to the loopback jack as described in DS1 Span Test.
  2. Test the CO-to-network interface wiring (Section 3 in the figure) using the Smart Jack loopback (CO responsibility). Coordinate this test with the DS1 provider.
  3. Test the short length of customer premises wiring (Span Section 2 in the following three figures) between the loopback jack and the Smart Jack. This can be done using a loopback that “overlaps” section 2 of the cable. Any of the following loopbacks can do this:
    1. The local ICSUs line loopback, which is typically activated, tested, and then deactivated by the DS1 service provider at the CO end.
    2. The local DS1 interface’s payload loopback, activated and tested by the DS1 service provider at the CO end.
    3. The far-end ICSU’s line loopback. This test is activated at the management terminal by entering test ds1-loop location far-csu-loopback-test-begin. The test is terminated by entering test ds1-loop location end-loopback/span-test. Bit error counts are examined as described in DS1 span tests. This test method is the least preferable because it covers wiring that is not in the local portion of the span. This test only isolates problems to section 2 wiring if there are no problems in the wiring between the far-end CO and the far-end ICSU. Coordinate this test with the DS1 service provider.

      If any of the tests fails, a problem is indicated in Section 2 as long as the tests for Span Section 1 and Span Section 3 pass. Since Span Section 2 includes the network interface point, it is necessary to work with the service provider to isolate the fault to the loopback jack cable, the “dumb” block, or the Smart Jack.