Draytek Vigor 2100 Series User Manual page 72

Volume Gain
MISC
DTMP
66
cannot find out a suitable one, please choose User Defined and fill
out the corresponding values for dial tone, ringing tone, busy tone,
congestion tone by yourself for VoIP phone.
Also, you can specify each field for your necessity. It is
recommended for you to use the default settings for VoIP
communication.
Mic Gain (1-10)/Speaker Gain (1-10) - Adjust the volume of
microphone and speaker by entering number from 1- 10. The larger
of the number, the louder the volume is.
Dial Tone Power Level - This setting is used to adjust the loudness
of the dial tone. The smaller the number is, the louder the dial tone is.
It is recommended for you to use the default setting.
DTMF mode – There are four selections provided here:
InBand:Choose this one then the Vigor will send the DTMF tone as
audio directly when you press the keypad on the phone
OutBand: Choose this one then the Vigor will capture the keypad
number you pressed and transform it to digital form then send to the
other side; the receiver will generate the tone according to the digital
form it receive. This function is very useful when the network traffic
congestion occurs and it still can remain the accuracy of DTMF tone.
SIP INFO: Choose this one then the Vigor will capture the DTMF
tone and transfer it into SIP form. Then it will be sent to the remote
end with SIP message.
Payload Type (rfc2833) - Choose a number from 96 to 127, the
default value was 101. This setting is available for the OutBand
(RFC2833) mode.
Vigor2100 Series User's Guide