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Background of the Invention
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	1.
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Field of the Invention
.ta 10
	This invention relates to
telephone central office main
distribution frames and, in particular,
to methods for wiring such frames.
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	2.
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Description of the Prior Art
.ta 10
	The main distribution frame
has been associated with telephone
central offices since before the
telephone system began to be
mechanized.
This eqipment serves as an
interface between the switching
equipment - the inside plant - and
the exchange cable network of
subscriber lines - the outside
plant.
The main function of the main
distribution frame is to establish
a point of flexibility in the
telephone system where any one of
the subscriber line cable pairs on the
outside plant side is connectible to
any of the terminating points on the
switching equipment side.
To perform this function in an
organized way, the main
distribution frame must hold all
of the cross-connecting wire,
called jumpers, in a  way that
permits operating personnel to
find one particular terminal pair out of
thousands of terminal pairs and
to interconnect or to change the
connection of this
terminal pair with another
terminal pair.
	One of the basic problems
with main distribution frames is
that in large switching centers
main frames can grow to lengths
of over 200|feet.
With mian distribution frames of
such length, the interconnection
of widely spaced apart terminal
pairs requires jumper cables
of a length comparable to the
length of the main frame.
Once jumpers of lengths greater
than a
few tens of feet are installed,
it becomes extremely difficult
to remove them when wiring changes
are made.
Quite frequently, the removal
of a relatively long jumper
from the main distribution
frame will
result in the abrading and
burning of the insulation
of neighboring wires.
Allowing an abraded jumper to remain
on the main frame would cause it to
be susceptible to malfunction
through short circuits.
Consequently, those
jumpers no longer in service
are generally allowed to remain
in place with new jumpers installed
over top of the
old jumpers.
In addition, the wiring of
main
distribution frame many feet in
length requires more than one
wireman to make an inter
connection or to effect a
change in wiring.
The result of this process
of administering and wiring
the main distribution frame
leads to increasing degrees of
jumper congestion and the 
ultimate failure of the main
frame.
	Accordingly, it is one
object of the present invention
to reduce the degree of jumper
congestion on a main distribution
frame.