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

[Rich Adamson]

Andrew Kohlsmith wrote:
> On Monday 24 April 2006 11:42, Ken Godee wrote:
>> cat5 is NOT T1 cable and if any telco/vendor tried
>> to install it in my location I'd have them pull it and
>> put in the proper cabling.
> 
> T1 cable is generally Cat3 is it not?  That's certainly how the old T1s loops 
> were run between the CO and the business...  From the smartjacks I've seen 
> shielded Cat3 but Cat3 nontheless.

No, cat3 isn't the same. But, for short distances and no induced noise 
(as stated previously) anything will do, even jumper wire.

The T1/E1 interface spec's are typically 75 ohm balanced (BNC, E1), 100 
ohm balanced, etc.

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.

R.