Shielding of T1/E1 cables WAS RE: Pinouts for T1/E1 crossover cable WAS "RE: [Asterisk-Users] what cable to connect a legacy PBX to a TE410P ?"

[Andrew Latham]

Also note that the Smart Jack allows the Telco to provide T1
Signalling in places that it couldn't in the past, most smart jacks
that I have used are:

[CO]<-Optical->[Hut DMS]<-->[Hut Smart Jack]<-HDSL->[CPE Smart Jack]

For the list, Telco Techs, mostly do as they are told, and are
schooled by the Telco vendors.


On 4/24/06, Rich Adamson <radamson at routers.com> wrote:
> Alexander Lopez wrote:
> > I was once told by a lineman that the cables they use didn't have that
> > many twists in them because it wasn't needed, and that the extra twists
> > would effectively use more cable and thus cost and weigh more than
> > triple what they do now.
>
> Good thing he doesn't work for a cable manufacturer as that's a total
> crock of crap that even an inexperienced person should be able to
> detect. (You can't twist two wires to make them weight three times as
> much, or cost three times as much.)
>
> > He told me that with the number of twists in
> > the Cat 5 cable it would cancel out any interference, but he also stated
> > that the effective length was calculated using a cable with less twists
> > and subsequently 'less dense' and that if using a Cat5e cable you must
> > factor that in. so if you use cat5e cable your are fine but you can't go
> > as far.
>
> Essentially true, but the impedance of a T1 cable is different from Cat5
> cables, which is one of the primary factors in limiting distance. Has
> nothing to do with the twists.
>
> Shielded vs non-shielded has to do with the environment, and how much
> electrical noise there is near the T1 cable. Nothing more, nothing less.
>
> > Regarding the Smart Jack it is mostly used as a location at the CPE
> > where the Telco can loop and make sure that the problem is at your end.
> > So your assumption is correct that you can plug anything you want into
> > it, its one your side of the demark, so if it doesn't work it's YOUR
> > problem.
>
>
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Andrew Latham - AKA: LATHAMA (lay-th-ham-eh)
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