Dtmf

Some articles on dtmf:

Cellular Data Communication Protocol - CC - Message Type
... CONGESTION CONTROL 1110 NOTIFY 1101 STATUS 0100 STATUS ENQUIRY 0101 START DTMF 0001 STOP DTMF 0010 STOP DTMF ACKNOWLEDGE 0110 START DTMF ACKNOWLEDGE 0111 START DTMF ...
Internet Radio Linking Project - Parallel Port Pin Assignments
5 Aux pin 2 (active high at parallel port) 6 Aux pin 3 (active high at parallel port) 10 DTMF 11 ... COS (active low on squelch open) 12 DTMF 13 ... DTMF 15 ... DTMF 18 ... Ground 19 Ground 20 Ground 21 ...
G.729
... Dual-tone multi-frequency signaling (DTMF), fax transmissions, and high-quality audio cannot be transported reliably with this codec ... DTMF requires the use of the RTP Payload for DTMF Digits, Telephony Tones, and Telephony Signals as specified in RFC 2833 ...
Malicious Caller Identification
... on their phone system—generally it is either a DTMF sequence such as *57 or a special button on their phone ... For analogue services, many exchanges will interpret DTMF sequences to activate POTS ... with PABXs with analogue phone connections, the PABX will interpret the DTMF and then activate the out-of-band signaling ...
Multiple Frequency-shift Keying - MFSK Fundamentals - 2-tone MFSK
... Perhaps the most widely used 2-tone MFSK system is dual-tone multi-frequency (DTMF), better known by its AT T trademark of "Touch Tone" ... Symbols in the DTMF and MF alphabets are sent as tone pairs DTMF selects one tone from a "high" group and one from a "low" group, while MF selects its two tones ... DTMF and MF use different tone frequencies largely to keep end users from interfering with inter-office signaling ...