Call input keys, each key can be received by any of

In the case of both sides of the phone, call them, one of them by pressing the phone's number keys, the other party can receive what key you pressed? I wonder if this idea could be achieved, what specific ideas<-! Main posts under Banner (D4) -><-! Posts under the main text (D5) ->
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Yes, the other side must have the ability to decode dtmf, and available in the market to sell this decoder chip.
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cited a floor tantahe reply:

possible, have the ability to decode dtmf each other, and the market has to sell this decoder chip.

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Phone should not receive it?
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Thank you very much, a floor to answer it right