-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Simon wrote: >> You seem to want to know the difference, FXO vs FXS. If I got this wrong, >> just >> delete it. FXS is meant to interface to a telephone set, so it gives talk >> battery and (as needed) ringing current. FXO is meant to interface to a line >> from a telco switch, so it accepts battery (if the circuit it's hooked up to >> doesn't give talk battery, you have no circuit) and expects to be rung into, >> so >> it detects ringing battery. Most of the time, both FXO's and FXS's offer >> options to operate in loop start (regular POTS) or ground start mode. Write >> me >> if you need more on that last. Options like reverse battery aren't usually >> offered in FXO/FXS cards. You usually have to give a FXS card your own >> source >> of ringing battery, not FXO, because an FXO is expecting to have ringing >> battery >> sent to it (from the telco switch it's connected to) to begin with. > > This brought an idea in my mind... the phone lines in our houses here > in Quebec,Canada are set so the line comes into the house at one point > (called dmark i think) then it is spread around. if there is no > service, then there is no dialtone, if one phone is used, then all > phones can hear the conversation if picked up. normal stuff. > but what if i were to setup a pc to work with asterisk and somehow > plugged a FXS (i guess?) card to any phone jack in the house. then > any normal phone would be networked to that FXS card and anything done > on them will go through the PC (the pc will actually take care of > sending a dialtone, etc...) am i correct, is this possible (to use > the existing POTS infrastructure)?
I'm afraid I don't completely understand how you'd do that. An FXS card is used when you want to interface between on kind of communications and another. Usually you have, at one end, a regular 2 wire line, a "POTS" line, but you'd only need this FXS card if the other size of the circuit differs: maybe it's a 4 wire circuit, maybe it's a DS0 channel of a T1, I don't know if folks are still using SF-based circuitry anymore (the ability to fake out the signalling is very well publicized nowadays). You comment about putting an FXS card on your house wiring isn't clear to me, but the electrical and communications effect would be similar to attaching an extra telephone set to your house wiring, I think. I could make more sense if YOU could make more sense, and tell me why you'd be using that FXS card (what sort of signalling conversion are you effecting?) One example might be to take your two wire house POTS line and remote it to a different state, like originating in Michigan, and adding a remote to New Mexico. You can't move a 2 wire line anywhere near that far, so you'd need to convert the signal to some format more well adapted to long distance travel. Again, it would be exactly as if you had added a new phone set to your house wiring. You'd hear if someone were listening this way, it wouldn't be silent. Creating a good tap of a 2 wire line would be possible, but not that easily, and it would have to be listening only, no ability to break into the conversation. > > Thanks > -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAknzeY8ACgkQz62J6PPcoOld6ACgkn1hjAV8LYyukPM2OVuIFfwQ zFEAn1e2kQrlIbR9gN7AS8MAiOZXHWTv =ux0T -----END PGP SIGNATURE-----
