[Asterisk-Users] Re: Shielding of T1/E1 cables WAS RE: Pinouts for T1/E1 crossover

[Andrew Kohlsmith]

On Monday 24 April 2006 12:42, Rich Adamson wrote:
> The T1/E1 interface spec's are typically 75 ohm balanced (BNC, E1), 100
> ohm balanced, etc.

Ahh yes, this is true.  Is that a typical spec for even POTS lines?

> I've never bothered to check to see if cat5 cables use the appropriate
> mating twisted pairs or not. Since the pinouts are different for cat5 vs
> T1 cables, I'd have to guess a single strand is used from two different
> twisted pair groups. That wouldn't be cool, but in short runs it
> probably doesn't have much of an impact.

Well Cat5 doesn't specify pinouts at all, just frequency response and 
crosstalk between pairs, IIRC.

-A.