Pseudo soundcard?

i’m currently preparing an installation of an asterisk server and i wonder about how the pseudo-soundcard thing works. i have no soundcard installed and voip-info.org says i don’t need one. of course, mpg123 tells me that a /dev/dsp is missing. on voip-info.org i’ve read something about oh323 acting as a pseudo soundcard - unfortunately i haven’t found anything else about ‘pseudo soundcards’ or how to run asterisk without a soundcard. can someone please shed some light on this issue, i’m a little puzzled atm. thx!

no one?