FXO or FXS?

Asterisk Asterisk Support
1

Hi,

I am currently setting up my first asterisk system for our new offices.

I have got a test machine up and running and can make and receive calls to different extensions via it.
The next step i need to under take is to start hooking it up to our analog lines as this is where I am getting a little confused.

To start off with we are going to have 4 analog lines, my aim is to use these to both receive calls and call out over.

Do I just require a 4 port FXS card or would I need a combination of FXO and FXS modules on the same card ?

Thanks for any help !!

2

Hi All,

I just managed to download the Asterisk the future of Telephony PDF and have found the answer I was looking for:

I will require a 4 port FXS to make and receive calls, the FXO module is for hooking up an analog phone or fax machine to the Asterisk server.

3

If I’m not mistaken, you need FXO ports.

The phone company provides an FXS. Your end has to be the opposite. A analog phone is an FXO.

Phone Company (FXS) —> into your asterisk box (FXO)

if you wanted to use analog phones with your asterisk box you need FXS.

out from your asterisk box (FXS) —> analog phone (FXO)

http://www.3cx.com/PBX/FXS-FXO.html