Broadband cable query for techies.

With my BB problems of late I though I'd get a spare lead for my router to
BB filter connection. On examination, I noted that the original cable,
which was supplied with the router, had only 2 contacts in the plugs at
each end, whereas the one I purchased had 4. Both w*rk OK but I wondered
why the difference? Anyone know?

JoeH...

*Take your pick*
from

There are 2 types of common modular plugs, the RJ-11 and the RJ-14. The
most common is the RJ-11 which uses only 2 of the wires in a 4 (or more)
strand wire. This is the same kind of plug that you use to plug your
telephone into the wall. This is a 1-line plug. The RJ-14 uses 4 wires and
is used to handle 2 lines, or 2-line phones.

My equipment (telephone, modem, computer...) has an RJ11 socket for
connecting the line cord. What are the connections?

It is clear from the answers given by uk.telecom readers that there IS NOT
ONE UNIQUE STANDARD. The two situations most likely to be met in practice
are these

* The middle pair of the RJ11 (pins 3,4) carries the phone line. The
line cord must connect that pair to pins 2 and 5 of the BT socket. This
would also be the situation with equipment brought from the USA.

* The line cord between the RJ11 and the BT plug is a straight cord. In
this case, the manufacturer has arranged to put the line onto pins 2 and 5
of the RJ11. It follows that UK models of this type of equipment
necessarily differ from the US models (in the USA, it is standard to use
pins 3,4 of the RJ11 for the phone line).

Flyiñg Ñuñ 2°°6 +...

Thanks. I wonder why my local pooter shop only stock the 4 contact ones?
Perhaps because they will be OK for both applications I suppose. Well the 4
contact one fits the 2 contact one's sockets, so I suppose RJ-11 and RJ-14
plugs fit the same sockets.