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(ASCEND) A Cautionary Tale (T-1s and Telcos)



An easy assignment for a new tech.  I sent him out to install
some Pipeline 130s on fractional T-1 lines.  I handed him
a floppy with the config files he would need, and gave him 
diagrams from my notebooks covering everything (what plugs 
where, RJ-48 and ethernet cable pinouts, upload instructions,
a screen dump of a "happy" P130 etc. etc.)

He got stalled on the first one.  The Pipeline was to be
installed "down the hall" from the telephone room.  Symptoms
were as follows:

        1) Plug (pre-programmed) Pipeline into RJ-48 cable to
           telco's Adtran "FNID", which telco had loopback
           tested only hours before.

        2) Pipeline reports "CARRIER" on status screen, but
           after a few minutes, goes to "Blue Alarm" (All
           Ones, meaning a bad upstream repeater or a problem
           upstream of an upstream repeater).  Ask tech to go 
           look at lights on Adtran. By then, all lights
           except the "power" light are dark.  (Strange,
           a Blue Alarm from a dead Adtran?  Hard to imagine.
           Maybe the Pipeline is confused by this state of
           affairs, and will not go to Red Alarm for some reason...)

        3) Call telco.  Yes, there IS a repeater in the circuit,
           since the customer premise is so far from the CO.
           Telco rolls truck to check repeater, tech goes to
           get coffee and wait for a pager message.

        4) Telco calls.  Nothing wrong with repeater, AND Adtran
           STILL loops back just fine, thank you very much.

        5) A puzzlement.  Page my tech, send him a message to go
           look at Adtran lights, call back with results.

        6) Tech calls back.  Only the Power light is lit on the
           Adtran.  A further puzzlement.  (Adtrans AND PairGains
           BOTH show 4 (count 'em, four) green solid lights when 
           they are happy).

        7) Pull out Adtran manual, look at descriptions of lights.
           We should have at least the "SX" light on, since a lack
           of an SX light means that there is no "Sealing Current" 
           to the telco side of the Adtran.

        8) Call back telco test position.  Compare circuit ids, 
           customer premise addresses, etc. (Multiple new frame
           relay drops ordered together, maybe they are testing
           the wrong circuit.)  No such luck.  They loop the
           Adtran again, claim all is well, and ask me if my tech
           might be drinking something other than coffee this AM.

        9) Page tech again, send him message to ask him to check 
           Adtran lights AGAIN, insure that there is only one 
           Adtran at that customer site, and insure that he is 
           looking at an Adtran and not a PBX component or 
           something.  Tech reports that only power light is lit 
           on ONLY box stenciled "Adtran".

       10) Tell my tech to unplug Adtran power supply from wall
           socket and cycle power on the unit.  (Maybe the customer
           prem side is "confused", and need a slap in the face.)

       11) Tech calls back.  "What power supply?", he asks.  (Tech
           had never seen an Adtran before.)

       12) Call Telco.  Ask them when Adtran units started being made
           without 120Vac power supplies.  Telco rolls truck to deliver
           missing power supply to customer site.

       13) Expected on-site tech time 20 mins.  Actual onsite tech
           time 1.5 hours.

        Conclusions:

                The voltage from the line itself IS enough to light 
                the "power" light on Adtran units, and enough to make
                the Adtran "work" from the point of view of the
                telco?

                The voltage is also just enough to charge up a few
                capacitors in the onboard DC power supply circuits,
                and make the Adtran "run" for a little while?

                Pipelines get something that they want to call
                "all ones" from an Adtran (List 1-5, Issue 2
                at least) that has no power on the customer
                premise circuitry?

                Plugging in Pipeline draws current, and discharges
                aforementioned capacitors in Adtran?

                Train your techs to look for the pretty green lights 
                (four, count 'em four!) FIRST !!

   How do Bevis & Butthead watch MTV with only a "rabbit-ears" antenna?

james fischer                                jfischer@supercollider.com

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