asterisk users - Dec 2004 - Sound problems with iaxcomm and Linux Fedora

Hi,

I just joinned the asterisk world and am very satisfied.  I'm trying
to use soft phone in linux.  However, i'm getting serious problems
with the quality of the sound.  When I try P2P connections (e.g.
192.168.0.40/s) it works well.  When I try to connections trhu
asterisk extensions, the connection is terrible.  This occurs in the
fedora Core 2 in all 4 machines that I tryied.

If I boot machine in windows and run ixcomm then everything functions
perfectly.

What i could try to improve the quality of the sound in IAX
connections from Linux softphone?

tks
-- 
Antonio Jos? dos Santos Brand?o