[LUNI] [OT] RJ45 568 A/B wiring scheme

[Mark Stuart Burge]

I always thought the A scheme was used for telephone systems while B was 
for ethernet

Pin to pin will work, but if the correct pairs are not twisted together 
as far as possible, you could get cross talk or interference.

Best stick with B and keep the twists right up to the connection.

Arun K. Khan wrote:
> For ethernet LAN purposes does it make any difference whether the RJ45
> connectors are crimped per 568 A or B as long as both ends of the cable
> follow the same scheme?  I have noticed that ready made cables use the
> 568B scheme.
>
> I have run 2 lengths of CAT5 (approx. 12m) from one end to another end
> of my house, both ends are crimped per 568A scheme (straight) and visual
> inspection and LAN wire testers check out OK.  
>
> However, the LEDs for resp. ports do not light up when I connect two
> switches at each end of the cables.  Whereas, the port LEDs on the 2
> switches (side by side) light up using a 568B (straight) cable.
>
> Suggestions what could be wrong with my cabling.
>
> TIA,
> -- Arun Khan
>
>