Grandstream GXP21xx Series User Manual - Manual (Page 56)

FIRMWARE VERSION 1.0.8.4 GXP2120/GXP2110/GXP2100/GXP14xx USER MANUAL Page 54 of 85
reliable with low-bit-rate codecs), via RTP (RFC2833), or via SIP INFO.
DTMF Payload Type
Configures the payload type for DTMF using RFC2833. The default value is
101.
Preferred Vocoder
7 different vocoder types are supported on the phone, including G.711 U-law
(PCMU), G.711 A-law (PCMA), G.723.1, G.729A/B, G.722 (wide band), iLBC
and G72-32. Users can configure vocoders in a preference list that is included
with the same preference order in SDP message.
Use First Matching
Vocoder in 200OK SDP When set to "Yes", the device will use the first matching vocoder in the
received 200OK SDP as the codec. The default setting is "No".
SRTP Mode
Enables the SRTP mode based on your selection. The default setting is
"Disabled".
Crypto Life Time Choose whether to include the lifetime parameter in SRTP crypto offer.
Symmetric RTP
Defines whether symmetric RTP is supported or not. The default setting is
"No".
Silence Suppression
Controls the silence suppression/VAD feature of the audio codec G.723 and
G.729. If set to "Yes", when silence is detected, a small quantity of VAD
packets (instead of audio packets) will be sent during the period of no talking.
If set to "No", this feature is disabled. The default setting is "No".
Voice Frames Per TX
Configures the number of voice frames transmitted per packet. When
configuring this, it should be noted that the "ptime" value for the SDP will
change with different configurations here. This value is related to the codec
used and the actual frames transmitted during the in payload call. For end
users, it is recommended to use the default setting, as incorrect settings may
influence the audio quality.
G723 Rate Selects encoding rate for G723 codec. The default value is 5.3kbps.
G.726-32 Packing Mode Selects "ITU" or "IETF" for G726-32 packing mode.
iLBC Frame Size Selects iLBC packet frame size. The default value is 30ms.
iLBC Payload Type
Specifies iLBC Payload type. The default value is 97. The valid range is
between 96 and 127.
Jitter Buffer Type
Selects either Fixed or Adaptive based on network conditions. The default
setting is "Adaptive".
Jitter Buffer Length
Selects Low, Medium, or High based on network conditions. The default
setting is "Medium".
Account x -> Call Settings
Early Dial
Selects whether or not to enable early dial. If it's set to "Yes", the SIP proxy
must support 484 response. The default setting is "No".