[asterisk-users] Dry Copper Pair

[Paul]

Eric "ManxPower" Wieling wrote:

> Jon Pounder wrote:
>
>> that's what "dry copper" is supposed to be, just a cross connect
>> between 2
>> pairs out of the CO. ie not even battery, line test equipment, or
>> anything
>> else hanging off it at the CO. any restriction should be purely a
>> function
>> of the inductance/capacitance of the wire and the connections and
>> nothing
>> else - anything else and you didn't get "dry copper" in the first place.
>>
>>
>> just out of curiousity - anyone ever hijack pairs and get away with it ?
>> (do your own cross connects on the street and utilize some crossconnect
>> all within one branch of F1 cable out of the CO ?)
>>
>> I've been tempted in the past, and know that at least around here I
>> would
>> probably get away with it for quite some time before anyone actually
>> cared
>> enough to investigate.
>
>
> At least in Bellsouth/Louisiana they do not guarantee that the circuit
> will pass DC voltage.   Since it is an alarm circuit I believe they
> only  guarantee that it will pass short/open.  If the circuit goes
> between COs then I there is no reason for them to pass DC voltage.  If
> it is within the same CO then there is no reason I can think of that
> it would not pass DC voltage, except of course to prevent people from
> using xDSL tech on the line.

A little history for the youngsters:

I remember when I was 7(that would be 1959), there were several false
alarms sent from the fire alarm box on the nearby street corner. I
watched the process of resetting the alarm box. It was much like
rewinding a clock. They swept up the pieces of broken glass on the
sidewalk and then installed a new glass pane in the alarm box.

The basic operation was that you pulled a handle down which broke
through the glass pane and triggered an unwinding of the clock spring
mechanism. That mechanism was basically a telegraph pulse sender. I was
standing close enough when they tested the box to hear the soft growl of
a spring driven motor and the clicking of the telegraph switch.

I don't know what the sending rate was for those devices. Whatever it
was, compare it to the bit rates we can now get over the same dry pair.
I think back then there were very few people who would believe that 40
years later(1999) over a megabit per second would be common.