Bandwidth used by the different codecs
When you are using Voice over IP, the used VoIPVoice over Internet protocol - A digital telephone system that uses the internet as the transmission medium, rather than the PSTN. phones and PBXPrivate Branch Exchange - System that connects telephone extensions and switches calls. can use different so called codecs. The consumption of bandwidth depends on which codec you use.
The following table gives you a short overview of the bandwidth consumption of the different codecs. On the page from asteriskguru.com, you can also find a bandwidth calculator tool.
|codec||name||bandwidth (incl. overhead)||bandwidth for 5 concurrent calls||quality|
|G.711 a/u-law||PCM||80 kbit/s||512 kbit/s||ISDNIntegrated services digital network - A technology enabling digital transmission of data and voice signals over a telephone network.|
|G.729||CS-CELP||32 kbit/s||200 kbit/s||good|
|iLBC||iLBC||32 kbit/s||200 kbit/s||good|
|G.723.1||MP-MLQ||21 kbit/s||110 kbit/s||average|
|G.723||A-CELP||15 kbit/s||80 kbit/s||average|
|GSM fullrate||GSM||13 kbit/s||80 kbit/s||average|
|G.726||AD-PCM||55 kbit/s||386 kbit/s||GSM|
|SpeeX||SpeeX||4 - 15 kbit/s||25 - 80 kbit/s||variable|