Matrix SPARSH VP710 User Guide
543
DTMF
DTMF (Dual Tone Multi-frequency) also known as touch-tone is used for telecommunication signaling over analog
telephone lines in the voice-frequency band. DTMF is the signal sent from the IP phone to the network, which is
generated when the keypad of the IP phone is pressed during a call.
Each key pressed on the IP phone generates one sinusoidal tone of two frequencies. One is generated from a high
frequency group and the other from a low frequency group.
The DTMF keypad is laid out in a 4 × 4 matrix, with each row representing a low frequency, and each column
representing a high frequency. Pressing a digit key (such as '1') will generate a sinusoidal tone for each of the two
frequencies (697 and 1209 hertz (Hz)).
DTMF Keypad Frequencies:
Methods of Transmitting DTMF Digits on SIP Calls:
The method of transmitting DTMF digits is configurable on a per-line basis.
•
RFC 2833
-- DTMF digits are transmitted by RTP Events compliant to RFC 2833.
•
INBAND
-- DTMF digits are transmitted in the voice band.
•
SIP INFO
-- DTMF digits are transmitted by SIP INFO messages.
RFC 2833
DTMF digits are transmitted using the RTP Event packets that are sent along with the voice path. These packets
use RFC 2833 format and must have a payload type that matches what the other end is listening for. The payload
type for RTP Event packets is configurable. IP phones default to 101 for the payload type, which use the definition
to negotiate with the other end during call establishment.
The RTP Event packet contains 4 bytes. The 4 bytes are distributed over several fields denoted as Event, End bit,
R-bit, Volume and Duration. If the End bit is set to 1, the packet contains the end of the DTMF event. You can
configure the sending times of the end RTP Event packet.
INBAND
DTMF digits are transmitted within the audio of the IP phone conversation. It uses the same codec as your voice
and is audible to conversation partners.
1209 Hz
1336 Hz
1447 Hz
1633 Hz
697 Hz
1
2
3
A
770 Hz
4
5
6
B
852 Hz
7
8
9
C
941 Hz
*
0
#
D
Summary of Contents for SPARSH VP710
Page 1: ......
Page 2: ......
Page 3: ...SPARSH VP710 The Smart Video IP Deskphone User Guide ...
Page 26: ...18 Matrix SPARSH VP710 User Guide ...
Page 28: ...20 Matrix SPARSH VP710 User Guide Phone Stand Handset Handset Cord Ethernet Cable Camera ...
Page 236: ...228 Matrix SPARSH VP710 User Guide ...
Page 322: ...314 Matrix SPARSH VP710 User Guide ...
Page 336: ...328 Matrix SPARSH VP710 User Guide ...
Page 468: ...460 Matrix SPARSH VP710 User Guide Click Confirm to save the change ...
Page 494: ...486 Matrix SPARSH VP710 User Guide The following shows a video call has been muted ...
Page 568: ...560 Matrix SPARSH VP710 User Guide Tap to save the change or to cancel ...
Page 637: ...Matrix SPARSH VP710 User Guide 629 Click Confirm to save the change ...
Page 724: ...716 Matrix SPARSH VP710 User Guide ...
Page 754: ...746 Matrix SPARSH VP710 User Guide ...
Page 764: ...756 Matrix SPARSH VP710 User Guide ...
Page 1041: ...Matrix SPARSH VP710 User Guide 1033 Application Compatibility List ...
Page 1045: ...Matrix SPARSH VP710 User Guide 1037 ...