Unicorn 3112 User Manual
Copyright © 2008
Hanlong Technology Co., Ltd
Page 36 of 42
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”.
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 Unicorn
3112 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.
This defines the encoding rate for G723 vocoder.
By default, 6.3kbps rate is chosen.
Voice Frames per TX
This sets the iLBC size in 20ms or 30ms
G723 Rate
This defines payload time for iLBC. Default value is 98.
The valid range is between 96 and 127.
