Cisco 521SG - Unified IP Phone VoIP Administration Manual page 310

Cisco SPA IP Phone Field Reference
Ext Tab
Cisco Small Business SPA300 Series, SPA500 Series, and WIP310 IP Phone Administration Guide
Parameter
DTMF Tx Volume for
AVT Packet
Use Remote Pref
Codec
Codec Negotiation
Description
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,
Telephony Tones and Telephony Signals
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.
If set to yes, the phone communicates using the
remote phone preferred codec. If set to no, the Cisco
IP phone communicates using its own preferred codec
(as indicated in the Preferred Codec field and in the
SDP by order of preferences). The default vale is no.
When set to Default, the Cisco IP phone responds to
an Invite with a 200 OK response advertising the
preferred codec only. When set to List All, the Cisco IP
phone responds listing all the codecs that the phone
supports. The default value is Default, or to respond
with the preferred codec only.
RTP Payload for DTMF Digits,
. According to
A
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