Can we send data across an analog phone line?

I wish to know whether it is possible to send data across PSTN network. While the call is in progress, I want to send some data through the telephone line (as DTMF tones can be sent开发者_如何学C). The data that I want to send is digital and is encrypted and modulated on an analog carrier (so that it can be send over an analog wire). I have also seen my broadband working in parallel when the call is going on.

I would guess PSTN work the same way throughout the world.

You can try to find an old modem that supports VoiceView. VoiceView allowed you to switch between voice and data on the same call, a capability that the standard modem protocols did not support.

You can just use an old fashioned modem.It can send data over the PSTN. However you can also use the rest of the bandwitch of the cable but will need ATM equipment to do this I would have thought.