What is RFC2833 DTMF?
RFC 2833 (RTP Payloads for DTMF Digits, Telephony Tones, and Telephony Signals) specifies an RTP payload format for carrying dual-tone multi frequency (DTMF) digits, and other line and trunk signals. RFC 2833 specifies a packet format for DTMF digits, line events, and trunk events.
What is DTMF payload type?
The DTMF Payload Type Number is the RTP Payload Type Number that indicates the transmitted packet contains DTMF digits. The dialed digit is encoded as an NTE (Named Telephone Event). As specified in RFC 2833, RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals, each dialed digit has a unique NTE.
What is DTMF type?
Dual-tone multi-frequency signaling (DTMF) is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers.
What is Outband DTMF?
Out-Of-Band Signaling. DTMF tones are an example of an in-band signaling protocol; that is, signals are sent over the same communications channel as the primary data on that channel. For DTMF tones that means that tones are in the same frequency range as human voice – any DTMF tones produced can be heard over the line.
Is RFC2833 inband or out-of-band?
In-band relates to the RTP media stream, while out-of-band relates to the signaling path. RFC2833 is the standards-based mechanism used to send DTMF digits in-band (RTP) that is supported by many vendors in the industry.
Is DTMF a RTP?
DTMF audio tones in the RTP stream (inband). This requires the use of lossless coders, such as µ-law or A-law. Named Telephone Events (NTEs) are specially marked event payloads in the RTP stream (inband). This is the most commonly implemented and the recommended practice.
What does Dtmfd stand for?
Dual tone multi-frequency (DTMF) is the sounds or tones generated by a telephone when the numbers are pressed. These tones are transmitted with the voice channel. DTMF is used to control automated equipment and signal user intent, such as the number they wish to dial. Each key has two tones at specific frequencies.