By connecting an analogue telephone that is already in your house to a FXO/FXS VoIP ATA, you can benefit from receiving and making normal calls over your telephone line and low cost, crystal clear VoIP calls via a router which is connected to the Internet (and you don't need to turn on your PC). Having an FXO/FXS VoIP ATA allows you to have each phone with its own VoIP line and make simultaneous VoIP Calls, Forward/receive PSTN calls from VoIP and visa versa.
Differences between FXO and FXS ports
- Connect to the Public Switched Telephone Network (PSTN is a conventional phone line, BT line for example).
- Having an FXO port on the adapter will allow you to switch between making/receiving VoIP calls (over the Internet) and calls over the PSTN (Analogue phone line, BT for example).
- Connect to analogue phones or fax machines.
- Each FXS port will enable you to connect an analogue telephone to the adapter to make or receive calls.
- VoIP adapters sometimes have more than 1 x FXS ports. 2 x FXS ports for example, would allow you to have 1 cordless DECT phone and one fax machine connected to the VoIP adapter, or 2 phones each with their own VoIP line.