VOIP CODECS


Making calls through mVoIP doesn’t mean sounding cheap.

Voice over IP lets you bypass your phone provider and make voice calls over IP connections – either private links or the open internet. Done poorly, mVoIP makes you sound like you’re at the bottom of a well. Done correctly, mVoIP can sound even better than a traditional phone call.

Voice over IP relies on a codec – a type of algorithm – to encode your voice for transmission and then decode it at the other end. There are many VoIP codecs to choose from, some of which save bandwidth by using compression and cutting out the high and low tones in your voice. Of course this comes at the expense of call quality.

Not to sound cheap the codec has been chosen based on the type of transport network and requirements of the VoIP. Each service, program, phone, gateway, etc typically supports several different codecs, and when talking to each other, they negotiate which codec they will use. When using the SIP client over a 3G (WCDMA) connection, the call quality can be vastly improved if the G729 or iLBC codecs are used.

Due to aforesaid we leave multiple codecs, however we set the priority among them. The table below suggests configurations you should be able to get good quality communication when the network condition is robust. Seems that the optimal voice clarity is attained by codecs iLBC and G729 at position 1 and 2, in that order, when using the SIP client over a 3G (WCDMA). No matter who the VoIP provider is, also with ones not listed here.

Depending on the device, improve the sound quality by selecting (note — “NET Settings” application, the older version is called “SIP VoIP Sett.”):

Menu > Tools (or Settings) > Connectivity > Net settings > Advanced VoIP settings VoIP Services and select the name of your Internet profile account to edit

or
Menu > Ctrl. panel > Net settings > Advanced VoIP settings VoIP Services and select the name of your Internet profile account to edit

or
Menu > Ctrl. panel > Connectivity > Net settings > Advanced VoIP settings VoIP Services and select the name of yourInternet profile account to edit

or
Menu > Settings > Connectivity > Admin.settings > Net settings > Advanced VoIP settings > VoIP services and select the name of your Internet profile account to edit

then scroll down to find

Codecs” and set their priority by “Options” -> “Move” them to position as proposed in the table below.

Priority SAUNALAHTI EUTELIA MESSAGENET
WLAN 3G WLAN 3G WLAN 3G
1 iLBC iLBC iLBC iLBC iLBC iLBC
2 G729 G729 G729 G729 G729 G729
3 AMR AMR-WB AMR-WB AMR-WB AMR-WB AMR-WB
4 PCMA AMR AMR AMR AMR AMR
5 CN CN PCMU PCMU PCMU PCMU
6 (**) (**) PCMA PCMA PCMA PCMA
7 (**) (**) CN CN CN CN

(**) An actual suggestion is to leave these fields blank

REMARK – “AMR-WB” is NOT supported by the Nokia VoIP client “S60 Rel 2.3″ nor “S60 Rel 3.0″, use any other remaining codecs instead.

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