[78223] in North American Network Operators' Group
Re: E1 - RJ45 pinout with ethernet crossover cable
daemon@ATHENA.MIT.EDU (Miquel van Smoorenburg)
Fri Feb 25 07:40:17 2005
To: nanog@merit.edu
From: "Miquel van Smoorenburg" <miquels@cistron.nl>
Date: Fri, 25 Feb 2005 11:42:25 +0000 (UTC)
X-Complaints-To: abuse@cistron.nl
Errors-To: owner-nanog@merit.edu
In article <cistron.Pine.WNT.4.61.0502251117300.4032@tech1.office.toastedmedia.net>,
Sam Stickland <sam_ml@spacething.org> wrote:
>Quick question: If I have two E1 ports (RJ45), then will running a
>straight ethernet cable between the two ports have the same affect as
>plugging a ballan into each port and using a pair of coax (over a v.
>short distance).
>
>Likewise would using an ethernet crossover cable have the same affect as
>swapping the pairs round on one balland.
>
>Or are the pinouts different to ethernet? I tried googling but couldn't
>find anything (perhaps because I can't seem to spell ballan :/ ).
The pinouts are different. It's easy to make your own E1 crosscable
though.
E1 uses pairs 4-5 and 3-6, just swap those.
4-5 <------------> 3-6
3-6 <------------> 4-5
(Oh it's "balun", from BALanced/UNbalanced, but you don't need one)
Mike.
