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New Member


I am trying to understand FXO and FXS, is this correct

I pbx will connect to a router with an FXO interface and stand alone ip phones can connect to the FXS interface on the router.

New Member

Re: FXO or FXS

Sort of.

A FXO port needs to connect to an FXS the PBX or the router has either is really no big deal unless you want a specific piece of equipment to be the on in charge of signalling.

The FXO port is like a phone endpoint (it is the type of port on any analog phone). The FXS port is like what a PBX or CO would have to connect to an analog port.

Generally, if you need an analog connection between two phone systems the FXS/FXO is probably the easiest but, the best would be E&M so you can connect a trunk connection.

New Member

Re: FXO or FXS

FXS ports provide TONE to devices Whether they are Phones, Faxes, or FXO cards. In eccense a line that comes from the CO is nothing more than an FXS port from the CO switch

FXO ports expect tone but do not send it. You use FXO ports to connect to FXS ports such as a CO line.

Hope this helps to clarify