asterisk users - Apr 2006 - Pinouts for T1/E1 crossover cable WAS "RE: what cable to connect a legacy PBX to a TE410P ?"

At Sangoma we do quite a lot of back-to back T1 and E1 
connections. T1 is not a very fussy connection, as the baud 
rate is only about 750 kbps.
 
In our experience, for error free communications you can use 
the following rules of thumb:
Up to 50 ft:  Flat patch cable
Up to 500 ft: Ordinary twisted telephone cable Cat 5 may be 
overkill unless you are going hundreds of feet.


David Yat Sin
Sangoma Technologies
(905) 474 1990 x119
(800) 388 2475 x199
MSN: david.ys1@hotmail.com
Email: davidy@sangoma.com
Wiki: http://sangoma.editme.com
 


> 
> Date: Mon, 24 Apr 2006 20:19:02 +0800
> From: Leo Ann Boon <leo@datvoiz.com>
> Subject: Re: Pinouts for T1/E1 crossover cable WAS "RE:
> 	[Asterisk-Users] what	cable to connect a legacy PBX 
> to a TE410P ?"
> To: radamson@routers.com, 	Asterisk Users Mailing List -
> 	Non-Commercial Discussion	
> <asterisk-users@lists.digium.com>
> Message-ID: <444CC236.101@datvoiz.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> 
> Rich Adamson wrote:
> 
> > <snip>
> > For short runs, the use of cat5 vs proper T1 cables isn't likely
to
> > have any impact unless there is a fair amount of induction from 
> > electrical noise, etc. That can take the form of florescent 
> fixtures, 
> > transformers, older CRT monitors, etc, etc.
> >
> > On longer runs, the shielded T1 cables are likely to provide better 
> > results particularly if there happens to be any electrical noise.
> >
> > Oh, and if shielded T1 cable is used, the shield at each end of the 
> > cable must be grounded. (Let's see how many can figure out 
> how to do 
> > that via an rj45 plug. ;)
> 
> Totally agree with you, unshielded cables are only usable if 
> the distance is short. Just curious, how should one ground 
> the shield? Do you ground it to the ground bar in the server 
> room? Any special requirements?
> 
> TIA
> 
> 
> 
> 
>

On 04/25/06 05:58 Sangoma Techdesk said the following:
> At Sangoma we do quite a lot of back-to back T1 and E1 
> connections. T1 is not a very fussy connection, as the baud 
> rate is only about 750 kbps.
>  
> In our experience, for error free communications you can use 
> the following rules of thumb:
> Up to 50 ft:  Flat patch cable
> Up to 500 ft: Ordinary twisted telephone cable Cat 5 may be 
> overkill unless you are going hundreds of feet.
we've faced weird intermittent problems and we suspect it's related to 
electrical interference caused by power cables et al in the server rack. 
we've seen this with both sangoma and digium cards when attempting to 
connect asterisk boxes to carrier E1s provided by the local operator. the 
cables used are normal cat5 UTP cables.

-- 
Regards,                           /\_/\   "All dogs go to heaven."
dinesh@alphaque.com                (0 0)    http://www.alphaque.com/
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