See what codec is being used

[bartdubelaar]

Yes I could do that. The order in the config file of the fritzbox is still like set in factory, with PCM coming first.
Maybe my VoIP provider is prioritzing iLBC to reduce it's own bandwidth consumption.

 

[gandalf94305]

Maybe my VoIP provider is prioritzing iLBC to reduce it's own bandwidth consumption.

Looks like it then... Forcing G.711 may be the solution.

Did you try? Did it work? ;-)

--gandalf.

 

[bartdubelaar]

I have set the Fritz Box to always use "Festnetz" quality. This should force PCM right? Well it still uses iLBC!!

Also I'm a bit confused about the settings I see in the fritzbox.export file when I export the settings:

        use_audiocodecs = no;
        audiocodecs = "PCMA", "PCMU", "G726-32";
        verbose = no;
        sip_prio = 0;
        rtp_prio = 0;
        dyn_codecs = yes;
        prio_low_codec = no;

Especially the first line confuses me, how can one possibly set up a voip connection without using a codec?? So this line is rather ambigious, what does it mean and why is it set to off? Also in the line of audiocodecs iLBC is not even listed. But it's not using codecs anyway so i suppose this has no influence.

 

[darbid]

I have set the Fritz Box to always use "Festnetz" quality. This should force PCM right? Well it still uses iLBC!!

The choice of codec to be used is done by two parties and is part of the SIP protocol. The box is but one of these parties. The choice of codec depends heavily on your VoIP provider, if they first support your choice and then in what order they support codecs. Is your only provider this voipplanet or are you trying others?

 

[bartdubelaar]

Sofar I'm just using "voipplanet" as a provider. I can specify which codecs I want to have available at a personal setup page provided by this provider. I specified that I want to use PCMA, PCMU, g.729 or iLBC.

So all these codecs are available from my providers part, as you can see in the voipd output when setting up the connection.

It is all not a big problem as iLBC is working for me right now. I just have the problem that sometimes when I call someone the call fails right at the start, or the other party can't hear me loud enough.
So I just wanted to see if using an other codec might help. But I first needed to figure out how the fritz box decides which codec to use.

But I think I will try to set up an account with an other voip provider to see if I encounter the same problems.

 

[maleas]

Every ata sends a list of codecs to the other side, with a specific "order" (most to least preferable). The other side must have at least one codec which is compatible with the offered ones. Furthermore, it is recommended (not required) for the other side to send back mutually compatible codecs in the same order received. Finally, the other side can _add_ codecs as well.

The strange thing here is that your device accepts iLBC, although most likely it never offered the option to do so...

For the record, why don't you disable iLBC altogether from the web page of your voip provider?

Alternatively, if you can edit Linux files using a vi-like editor, modify the following lines of /var/flash/voip.cfg, save it and then restart the voip daemon with voipcfgchanged.

/var/flash/voip.cfg
        use_audiocodecs = yes;
        audiocodecs = "PCMA", "PCMU";
        verbose = yes;
        sip_prio = 0;
        rtp_prio = 0;
        dyn_codecs = no;
        prio_low_codec = no;

 

[bartdubelaar]

Thanks for the tip on editing voip.cfg. I've already traced back al my problems to my voipprovider. I've signed up with voipbuster and have been using voipbuster now for one week with no problems whatsoever. Good audioquality and it uses PCM like it should (I know voipbuster doesn't even offer iLBC). So it think is was just my crappy voipprovider.
I was using that voipprovider because you can just get a bill for the calls, which I prefer over voipbuster which uses credit that you have to fill up manually. But I can live with that if voipbuster gives a better service.