VoIP How to: Voice reinjection: Difference between revisions

One needs an ADSL microfilter of the typeas supplied with modem/routers over the years. It needs to be of the type where the connection to the line is made with a short BT plug to an RJ11 plug (American style) - i.e. the microfilter has two RJ11 sockets on it, and one BT phone socket. One also needs an ''appropriate'' RJ11 plug to RJ11 plug lead. Remove the existing RJ11 lead from the VDSL SSFP, plug one end of the new RJ11 lead into the VDSL SSFP, and the other end into the 'line' connection of the microfilter. Now plug the free end of the old RJ11 lead into the microfilter, and ensure the modem/router regains sync. Now the phone socket on the microfilter is connected to the copper pair.

There areis a few gotchasgotcha regarding the wiring of RJ11 sockets. The VDSL SSFP uses pair 1 (pins 3 and 4) on the connection for the modem/router. I have thetwo oddsuitable microfiltermicrofilters, wherebut they both have the RJ11 (or RJ14 ?) line socket useswired using pair 2 (pins 2 and 5) instead (although the RJ11 out to the modem/router is wired as pair 1), so one would needneeds a crossover RJ11/14 cable between the VDSL SSFP and the microfilter. It's easier if one has a box of spare microfilters and leads... the crossover cable would need to wire pin 2 at one end to pin 3 at the other end, 3 to 2, 4 to 5, and 5 to 4.