On Thu, 07 Feb 2008 20:41:56 -0800, Don Bowey wrote:

:
:Everything is "good" until it fails. Perhaps it was the first pair damaged
:by a gopher or a heavy rain.

A self evident truth.

A gopher may damage a cable and affect maybe a single pair or two, which is not
so bad, as long as it doesn't rain. However, when water ingress occurs almost
every subscriber in that cable will be affected and repairs are urgently carried
out.

:
:No, it doesn't mean the assignment records were faulty. It means the
:assignment people weren't aware of a general cable fault at that time.

I haven;t even mentioned a "general cable fault".

If the faulty pairs are in a local drop cable, which you admit are not
'assigned' (are local drop faulty pairs even recorded?), then of course the
assignment centre will not be aware of them.

:
: It is obvious that there are at least 2 local drop pairs to the OP's area
: which are faulty, so there is a very good chance that there are several more
: in that cable as well.
:
:Are you changing the topic from distribution cable pairs to drop pairs?
:It's apples and oranges. Drops are not "cable pairs" and are not assigned
:by the assignment center.

On any exchange MDF (copper only in this discussion) there will be Junction
cables (J1, 2 etc) running between exchanges for inter-exchange traffic and
there will be main distribution cables (C1, C2 etc) to carry exchange services
to local subscribers.

The main distribution cables from the exchange MDF travel along major routes and
at various points drop off pair ranges in local distribution pits or cross
connection facilities on street verges - out here we use cable pillars
http://www.export61.com/companydetail.asp?cid=165 but you may use cabinets where
you are. From the pillars, local drop cables (they are referred to as
Distribution Area pillars and are marked DA-xx where xx is the pillar number)
feed the houses from the street via underground cable pits - usually, 1 pit
between two adjacent houses. The customer cable from the pit enters the premises
via a wall mounted network termination enclosure where internal cabling may be
brought to for connection to the line via a network termination device if
required.

Since neither the OP, you, or myself knows which part of the pair between the
exchange and the premises was changed, then it is impossible to say whether the
faulty pair/s used were in the local distribution cable or the main cable. The
main cable pair originally assigned to the OP's premises may have been perfectly
ok but the local drop pair from the street distribution pillar to the premises
may have been the culprit. This might explain why the pair the liney unknowingly
chose a faulty local drop pair. He would naturally record the cross connection
details for the assigned main cable pair but because these local drop pairs are
not assigned by the assignment centre, it is probable they don't know about
them. There is a strong likelihood that there will be more than one unrecorded
unserviceable pair in any local drop cable.

My contention is that when called out to fix the OP's poor DSL connection the
liney selected a spare local drop pair in the local drop pillar/cabinet, ran a
new jumper and then opened the premises feed pit and connected the premises feed
cable to that new pair. Unfortunately, his first selection proved the pair to be
unserviceable and he chose another local pair and re-jumpered in the
pillar/cabinet and re-joined again in the local feed pit. This time his choice
was successful.

:
: Until all good pairs in the cable are in use
: the telco won't bother to upgrade or repair the faulty pairs - it costs too
: much to just fix one or two pairs so they wait till they absolutely have to
do
: something - I know how they work.
:
:You do not "know how it works" except perhaps in a very narrow area.
:Finding two bad pairs in a localized area of a distribution cable is cause
:to find and repair the cause(s).
:
:

Two bad pairs in a local drop cable, where there are no other reports of
problems from existing subscribers, does NOT constitute a reason for a find and
repair callout. The unserviceable pairs may simply be due to poor jointing
technique by a previous liney, but these will in no way affect other working
subscribers.

Local drop pairs which are unserviceable but are not due to a cable damage fault
or water ingress, are simply ignored until such time as there is a strong reason
to go out and fix the faulty pairs. This usually only occurs when the cable is
at full capacity and a new subscriber connection is required. Only then does it
become necessary to find why the unserviceable pairs are faulty and fix them.
So, unserviceable pairs simply lie around waiting to be allocated and
re-allocated and only get repaired when there are no remaining good pairs
available. It is a simple matter of economics.