Grandstream Networks 496 User Manual page 31

HandyTone-496 User Manual
Preferred Vocoder
G723 Rate:
iLBC frame size:
iLBC payload type: This defines payload time for iLBC. Default value is 97. The valid range is
Voice Frames per
TX
Silence Suppression This controls the silence suppression/VAD feature of G723. If set to "Yes",
Fax Mode
The HandyTone ATA supports up to 6 different Vocoder types including G.711
A-/U-law，G.723.1, G.726, G.729A/B, iLBC. Depending on the product
model, some of these Vocoders may not be provided in standard release.
Users can configure Vocoders in a preference list that will be included with the
same preference order in SDP message. The first Vocoder in this list can be
entered by choosing the appropriate option in "Choice 1". Similarly, the last
Vocoder in this list can be entered by choosing the appropriate option in
"Choice 6".
This defines the encoding rate for G723 vocoder. By default, 6.3kbps rate is
chosen.
This sets the iLBC frame size in 20ms or 30ms
between 96 and 127.
This field contains the number of voice frames to be transmitted in a single
packet. When setting this value, the user should be aware of the requested
packet time (used in SDP message) as a result of configuring this parameter.
This parameter is associated with the first vocoder in the above vocoder
Preference List or the actual used payload type negotiated between the 2
conversation parties at run time.
e.g., if the first vocoder is configured as G723 and the "Voice Frames per TX"
is set to be 2, then the "ptime" value in the SDP message of an INVITE request
will be 60ms because each G723 voice frame contains 30ms of audio.
Similarly, if this field is set to be 2 and if the first vocoder chosen is G729 or
G711 or G726, then the "ptime" value in the SDP message of an INVITE
request will be 20ms.
If the configured voice frames per TX exceeds the maximum allowed value, the
HandyTone ATA will use and save the maximum allowed value for the
corresponding first vocoder choice. The maximum value for PCM is 10(x10ms)
frames; for G726, it is 20 (x10ms) frames; for G723, it is 32 (x30ms) frames;
for G729/G728, 64 (x10ms) and 64 (x2.5ms) frames respectively.
when a silence is detected, 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.
T.38 (Auto Detect) FoIP by default, or Pass-Through (must use codec
PCMU/PCMA)
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