2.2 Programming
20
Programming Guide
Jitter buffer Settings (G.711 for Fax)
CODEC Frame Settings
The parameters below are used to set the interval between packet transmissions for each type of CODEC. It
is recommended that all VoIP Gateway Cards in a VoIP network have the same settings for these parameters.
For details, refer to "Detailed Explanations".
Echo Canceller Settings
Parameter
Default
Value Range
Jitter Buffer Minimum (ms)
50
10 × n (n = 4–10)
Jitter Buffer Maximum (ms)
500
10 × n (n = 4–50)
Parameter
Default
Value Range
G.723.1 Packet Sending Interval (ms)
30
30, 60, 90
G.729A Packet Sending Interval (ms)
20
20, 30, 40, 60
G.711 Packet Sending Interval (ms)
20
20, 30, 40, 60
Parameter & Description
Default
Value Range
Echo Canceller
Specifies the length of the echo canceller (in milliseconds)
when using the echo cancellation feature (G.168), or disables
the feature.
Echo is the audible duplication of a caller's voice on the return
path; when echo exists, the caller hears his or her own voice
after some delay. The echo canceller eliminates this echo.
Generally, the default length of 48 ms will suffice. However, if
an echo is still heard, it is recommended that you set the
length to 128 ms.
Note
There are various factors that may cause an echo. In
some cases, this feature does not eliminate the echo
entirely.
48
48, 128, Don't use
