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TAU-4M.IP Subscriber gateway
linear encoding and U-law is non-linear). The U-law encoding is used in North America, and the A-law encoding–
in Europe.
G.722
is a broadband codec that uses ADPCM compression algorithm with range division at the rate of 48,
56 and 64 kbps.
G.723.1 is a voice data compression codec, allows for two operation modes: 6.3kbps and 5.3kbps. G.723.1
codec has a voice activity detector and performs comfort noise generation at the remote end during period of
silence (Annex A).
G.726-32 is a voice data compression codec that uses ADPCM compression algorithm at the rate of
32kbps.
G.729 is also a voice data compression codec with the rate of 8kbps. As with G.723.1, G.729 codec
supports voice activity detector and performs comfort noise generation (Annex B).
Codec 1...7
- allows you to select codecs and the order of their usage. Codec with the highest
priority should be placed in 'Codec 1' field. For processing it is necessary to point at least one
codec:
–
Off
– codec is not used;
–
G.711A – use G.711A codec;
–
G.711U – use G.711U codec;
–
G.723 – use G.723.1 codec;
–
G.729 (A,B) – use G.729 annexA or G.729B codec;
–
G.726 – 24–use G.726 codec with 24 kbps speed;
–
G.726 – 32–use G.726-32 codec with 32 kbps speed;
–
G.722 – use G.722 codec;
Packet time
- voice milliseconds amount in one RTP packet (for codecs G.711, G.729, G.723 and
G.726);
Payload type
—dynamic load type for G.726-24 or G.726-32 codecs (allowed values – from 95 to
127).
Alternative voice codecs may be specified for chosen direction. There is ability of preferred
codec setting for voice transmission for every direction in dialplan. Configuration is processing
in dialplan. For every direction codec settings are pointed in parenthesis after word 'codecs:'.
If it is necessary to use several codecs, they must be listed with symbol ',' between them. It is possible to
set several parameters for direction. In this case they must be divided by symbol ';' -
(param1:subparam1,subparam2;param2:subparam1,subparam2). Allowed subparamX subparameters values:
g711a, g711u, g729, g723.
Allowed param1 - codecs and param2 - rfc2833_PT subparameters values:
Example:
([23]xxx(codecs:g729; rfc2833_PT:96)|8x.(codecs:g711a;g711u)).
Jitter Buffer
