Dtmf Key < 2026 >

| | 1209 Hz | 1336 Hz | 1477 Hz | 1633 Hz | | :--- | :---: | :---: | :---: | :---: | | | 1 | 2 | 3 | A | | 770 Hz | 4 | 5 | 6 | B | | 852 Hz | 7 | 8 | 9 | C | | 941 Hz | * | 0 | # | D |

In modern telecommunications, DTMF is handled in two distinct ways depending on the network type: dtmf key