Codec Support and Configuration

1. Codec Support
2. Asterisk Codec Configuration
3. FreeSWITCH Codec Configuration

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The following chart details all codecs supported by all Sangoma Transcoding hardware

 

 

Codec	P time (ms)	Codec	P time (ms)
G711 ulaw	10,20,30,40,50ms (64 kbps/8 Khz)	G722	10,20,30,40ms (64 kbps/8 khz)
G711 alaw	10,20,30,40,50ms (64 kbps/8 Khz)	GSM_FR	20 ms (13 kbps/8Khz)
L16 linear	10,20,30,40,50ms (128 kbps/8Khz) 10,20,30,40,50ms (256 kbps/16Khz)	GSM_EFR	20ms
G729 AB	10-200ms (8 kbps/8 Khz)	ILBC	20,40,60ms (15.2kbps/8Khz) 30,60ms (13.3kbps/8Khz)
G723.1	30,60,90ms (5.3kbps/8Khz) 30,60,90ms (6.3kbps/8khz)	G726	10,20,30,40,50ms (32kbps/8Khz)
G722.1 (Siren 7)	20ms (24kbps/16Khz) 20ms (32kbps/16Khz)	AMR	20,40ms (4.75kbps/8Khz) 20,40ms (5.15kbps/8Khz) 20,40ms (5.90kbps/8Khz)

 

*Note: The above Codec Support is based on the hardware (independent on the application above) 

 

The Chart below indicates Asterisk & FreeSWITCH supported Codecs

Codec

G711 ulaw

G711 alaw

L16 Linear

G729ab

G723.1

G722

GSM_FR

ILBC

G726

AMR

G722.1

GSM_EFR

Asterisk

Y

Y

Y

Y

Y

Y

Y

Y

Y

N

N

N

FreeSWITCH

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

N

Legend:   Y - Supported codec
                N - Unsupported codec

 

-> Asterisk: P time(s) are hard-coded at 20ms and cannot be changed
 ->FreeSWITCH:  P time(s) up to and including 50 ms are supported

 

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Asterisk Codec Configuration

 

The Sangoma transcoder will perform transcoding for all codecs listed in the codec module configuration file: sangoma_codec.conf.
By default, the codec module is already pre-configured to perform all codec translations for G729.  If you require only g729 translations you do not need to edit any information.

If you require the transcoder to perform transcoding for additional codecs, edit sangoma_codec.conf and add the translation with the following syntax:

-> register=XX     Where 'XX' represents the codec of your choice (ie. register=pcmu)

If only one codec is specified in the command above, then all possible translation combinations for that codec will be registered. For example "pcmu" , (pcmu->alaw,  alaw->pcmu, g723->pcmu,  pcmu->g723,  gsm->pcmu, pcmu->gsm…etc)

If you register specific translation paths, (i.e g729toulaw, ulawtog729), then the codecs will be invoked for only those translations combinations, and no other.

If you wish to NOT register a codec or translation, edit sangoma_codec.conf and add the translation with the following syntax:

-> noregister=XX    Where 'XX' represents the codec of your choice ie. pcmu 

Asterisk supported codecs with their syntax in sangoma_codec.conf Codec register= G711 ulaw pcmu, ulaw G711 alaw pcma,alaw L16 Linear slin G729AB g729 G723.1 g723.1 G722 g722 GSM_FR gsm ILBC ilbc G726 g726

sample sangoma_codec.conf file with various codec usages:

 

-> After editing your codecs in sangoma_codecs.conf, you must either restart Asterisk, or reload the codec module in asterisk ("module reload codec_sangoma.so")

 

Type 'sangoma show codecs' at the Asterisk CLI for a list of supported codecs

Type 'sangoma show translators' at the Asterisk CLI for the list of translators registered

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FreeSWITCH Codec Configuration

The Sangoma transcoder will perform transcoding for all codecs listed in the codec module configuration file: sangoma_codec.conf.xml
By default, the codec module is already pre-configured to perform all codec translations for G729.  If you require only g729 translations you do not need to edit any information.

If you require the transcoder to perform transcoding for additional codecs, edit sangoma_codec.conf.xmland add the translation with the following syntax:

-> <param name="register" value="X"/>     Where 'X' represents the codec of your choice (ie. <param name="register" value="amr"/>)

If you wish to NOT register a codec or translation, edit sangoma_codec.conf and add the translation with the following syntax:

-> <param name="noregister" value="X"/>    Where 'X' represents the codec of your choice ie. pcmu

 

FreeSWITCH supported codecs with their syntax in sangoma_codec.conf.xml Codec register= G711 ulaw pcmu G711 alaw pcma L16 Linear slin G729AB g729 G723.1 g723 G722.1 g7221 g722 g722 GSM_FR gsm ILBC ilbc G726 g726-32 amr amr

sample sangoma_codec.conf.xml file with various codec usages:

 

 -> Type 'show codecs' in FS CLI and all codecs prefixed with "sangoma" are registered by the trascoder

-> Type ' sangoma_codec sessions' in FS CLI to see codec session with RTP information