Configuring DS1 without a Smart Jack

Last Updated : Apr 28, 2014 |

About this task

Testing is divided into two steps:

Procedure

  1. Test customer premises wiring (section 1 in the figure) from the ICSU to the loopback jack as described in DS1 span tests.
  2. Test the loopback jack-to-dumb block and dumb block-to-CO wiring (Span Section 2 in the figure). This can be done using a loopback that “overlaps” the section of the span. Any of the following loopbacks can do this:
    1. The local ICSU’s 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 the “DS1 Span Test” section. This test only isolates problems to Span 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 above tests (a, b, or c) fail, a problem is indicated in Span Section 2. This could mean bad loopback jack -to-dumb block cabling, but is more likely to indicate a problem somewhere between the “dumb” block and the CO. This is the responsibility of the DS1 service provider. If the DS1 span test confirms that there are no problems in section 1, the technician should proceed as follows to avoid unnecessary dispatch.

    • Identify and contact the DS1 service provider.

    • Inform the DS1 provider that loopback tests of the CPE wiring to the “dumb” block (section 1) showed no problems.

    • If the far-end ICSU line loopback test failed, inform the DS1 provider.

    • Request that the DS1 provider perform a loopback test of their portion of the Span Section 2 wiring by sending someone out to loop Span Section 2 back to the CO at the dumb block.

    If this test fails, the problem is in the service provider’s wiring.

    If the test passes, the problem is in the cable between the loopback jack and the dumb block. Replace the loopback jack.