HandTone-496 User Manual
Grandstream Networks, Inc.
23
Preferred Vocoder
The HandyTone ATA supports up to 7 different Vocoder types including G.711
A-/U-law
，
G.723.1, G.726, G.728, 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 7”.
Voice Frames per
TX
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.
G723 Rate:
This defines the encoding rate for G723 vocoder. By default, 6.3kbps rate is
chosen.
iLBC frame size:
This sets the iLBC size in 20ms or 30ms
iLBC payload type:
This defines payload time for iLBC. Default value is 98. The valid range is
between 96 and 127.
Silence Suppression
This controls the silence suppression/VAD feature of G723 and G729. If set to
“Yes”, 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.
SIP Registration
This parameter controls whether the HandyTone ATA needs to send
REGISTER messages to the proxy server. The default setting is “Yes”.
Unregister on
Reboot
Default is No. If set to yes, the SIP user will be unregistered on reboot.
Layer 3 QoS
This field defines the layer 3 QoS parameter which can be the value used for IP
Precedence or Diff-Serv or MPLS. Default value is 48.
