13 audio settings – GAI-Tronics VoIP Telephone Software Configuration Guide User Manual
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VoIP Telephone Configuration Guide
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5.13 Audio settings
This page sets various audio parameters within the telephone
CODEC: This setting chooses the CODEC order of preference that will be used by the phone.
It is made up of a list of values from 1 to 6, separated by commas.
The values have the following meanings:
1 = G.711 A-law
4 = G.729 a/b
2 = G.711 u-law
5 = G.723.1 MP-MLQ (6.3kbps)
3 = G.722
6 = G.723.1 ACELP (5.3kpbs)
Example: 6,5,4 would set the order of preference to be G.723.1 ACELP followed by G.723.1
MP-MLQ followed by G.729. None of the other codecs would be included.
NOTE: If codecs 5 & 6 are both used, they must be next to one another in the list.
SAMPLE: Sets the sample period for the G711, G722 and G 729 codecs to be either 10 or
20ms (individually). Default setting is 20ms.
NOTE: the sample size cannot be bigger than the packet size (packet size = frames per
packet x frame period). Normally the packet size will be at least 20ms, but if you have set a
low packet size (see below), you may need to set the sample period to 10ms.
FRAMES: sets the number of audio sample periods or “frames” per IP packet.
Default values:
G.723.1 = 1.
Each frame is 30ms (20 or 24 bytes), range is 1-4 frames
G.729 = 2.
Each frame is 10ms (10 bytes), range is 2-10 frames.
G.711 = 20.
Each frame is 1ms (8 bytes), range is 10-100 frames.
Increasing the number of frames per packet allows the bandwidth used on the IP connection
to be minimised, but increases transmission delay.
Decreasing the number of frames per packet reduces transmission delay but increases the
bandwidth used.
Note: the packet size (frame size x frames per packet) must be greater than the sample size
(see above). Make sure the SAMPLE size and FRAMES value for each codec are set
accordingly.
VAD: Enables or disables the use of Voice Activity Detection. This command is only valid for
G723 and G729 Codec settings. The default value is OFF. Note that when using the G729
codec, VAD must be set to on.
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