1 Reply Latest reply on Sep 25, 2014 9:46 AM by srblush

    TA 1500 Erratic Ringing Trouble

    srblush New Member

      What it is-


      Affects multiple customers, it sometime acts like a ring trip but most often rings with short rings, stuttered rings, or normal rings. Not consistent but you can never get normal ringing for more than 4 test calls before it happens. One customer may ring normal 3 times and another may trip instantly at the same time.


      What’s been done-


      All new common cards, CO and RT

      New line cards for affected customers

      New CO shelf


      Working with our Tech Support installed latest software and provisioned per their advice.This was done a couple of months ago and did not clear the trouble. What finally did clear the problem that time was removing the 20 hz ring fuses in the CO PSU. We suspected this may be a symptom if a problem with the shelf backplane. The problems stayed clear until last week. Yesterday I replaced the CO shelf which did not fix the problem. Any help would be greatly appreciated.




      QuadC-POTS Provisioning

      1.  Circuit                           Circuit 1

                      2.  Mode                             TR08 Universal VG

                      3.  Transmit TLP                +0.0 dB

                      4.  Receive TLP                 +0.0 dB

                      5.  Trunk Processing           Busy in CFA

                      6.  NBOC                             0 nF

                      7. Ring Ground Disable       Active




      Quad R-POTS Provisioning

                        1.  Circuit                                Circuit 1

                        2.  Mode                                 TR08 Auto

                        3.  2-Wire Termination            600 + 2.16uF

                        4.  Transmit TLP                     +2.0 dB

                        5.  Receive TLP                       -2.0 dB

                        6.  Trunk Processing              Busy in CFA

                        7. On-Hook Messaging          Enabled

                        8.  NBOC                                0 nF


      Bank Provisioning

                          1.  Bank Mode                           SLC-96 Mode I

                          2.  Counting Sequence              D1D

                          3.  Inband Loopback                  Enable

                          4.  Protection Line Switching     Enable


      DS1 Circuit Provisioning

                            1.  Circuit Select              Circuit A

                            2.  Operation State              Enable

                            3.  Line Buildout                   0-133 ft

                            4.  Line Code                        AMI

                            5.  Framing                           SLC-96

                            6.  Bipolar Violation Ratio     10e-4



      A-  SLC-96

      B- SF

      C- SF

      D- SF

      P- SLC-96

        • Re: TA 1500 Erratic Ringing Trouble
          srblush New Member

          We found the solution. I was misinformed about the problem; I
          thought it affected the whole shelf but later found that it was just a few
          customers.  After replacing the system
          from end to end and verifying the provisioning we still had problems.  The calls would ring normally at the frame
          going into the TA 1500 but would have short rings or no rings at the RT. We
          eliminated the CO as the problem because of this. After finding a good ringing
          number I moved it on the frame to a known bad line through the TA 1500. It rang
          fine on every pair we moved it to. I checked the records and found that the
          trouble lines shared the same LCE OE switch equipment. I cut them to OE’s in a
          different LCE and they work fine. My only conclusion is that the signaling from
          the older LCE, although it works fine in the CO, loses something in the
          signaling when it passes through the TA 1500. The LCE that solved the problem
          is newer equipment.