RE: [GnomeMeeting-list] MS-GSM sound quality

[<lurch gmx li>]

> Hello,
> I am using Ekiga with MS-NetMeeting through VPN. I have the 
> encryption 
> turned off on the VPN server. If I enable the MS-GSM codec, I 
> find the 
> sound quality extremely bad. As if there is a LF ring modulation or a 
> bad sampling frequency conversion. I tried to change the 
> values of the 
> minumum jitter buffer to 125ms or 250ms, with no effect. I 
> would expect 
> a sound quality similar to a mobile phone. Am I right to 
> understand that 

The MS-GSM Codec is very similar to the GSM 06.10 Codec (specified in the
GSM Standard), the parameters are identical, only bitstuffing differs. This
Codec has had it best days, it is almost 20 years old, and is nowadays only
implemented as a fallback in mobile phones, which also support the GSM 06.60
Enhaced Full Rate (EFR) or even AMR, which give a much better speech
quality.

> the Speex codecs in NM cannot interoperate with Ekiga? I 
> don't think the 
> problem comes from the VPN, because the sound is perfect with the PCM 
> codecs.

I don?t know if this is still correct, but I would suggest that you try a
different softphone on the Windows workstation supporting the SIP protocol,
there are plenty of programs, many of these are also free (as in beer and/or
speech), and if you have some expertise with computers, you may also try the
Ekiga Win32 preliminary version.

> Thanks
> Stephan.

Greetings,

Stefan