Cisco SPA 500 Series and Wireless IP Phone Field Reference
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Cisco SPA 500 Series and WIP310 IP Phone Administration Guide
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Release Unused Codec
Allows the release of codecs not used after codec
negotiation on the first call so that other codecs can be
used for the second line. To use this feature, select yes.
Defaults to yes.
DTMF Process AVT
Select yes to process RTP DTMF events. Otherwise,
select no. If this parameter is set to no, the AVT
payload type is not included in outbound SDP.
Defaults to yes.
Silence Supp Enable
To enable silence suppression so that silent audio
frames are not transmitted, select yes. Otherwise,
select no. See
Ensuring Voice Quality, page 114
.
Defaults to no.
DTMF Tx Method
Select the method to transmit DTMF signals to the far
end: InBand, AVT, INFO, Auto, INFO, or
AVT+INFO. InBand sends DTMF using the audio path.
AVT sends DTMF as AVT events. INFO uses the SIP
INFO method. Auto uses InBand or AVT based on the
outcome of codec negotiation.
Defaults to Auto.
DTMF Tx Volume for AVT
Packet
Allows you to manually configure the AVT Tx volume.
The value of this parameter is inserted into the volume
field of the payload in the AVT packet.
Values are based on the AVT specification as
described in RFC 2833,
RTP Payload for DTMF Digits,
Telephony Tones and Telephony Signals
. According to
RFC 2833, the volume field is represented by 6 bits,
and describes the power level of the tone, expressed
in dBm0 after dropping the sign.
Valid range for this parameter is 0 to 63. If the
provisioned value is negative, it will be negated first.
Thereafter, if the value is beyond the high limit of 63, it
will be clipped to 63.
The default value is 0, and is the recommended setting.
However, some gateways do not accept this volume
setting. If the gateway does not accept the value of 0,
the DTMF tone is not relayed to the remote end. As a
workaround for the phone to interoperate with those
gateways, you can change the value to a value greater
than 0.
Parameter
Description
