You're not sending samples though, you are just sending the audio from the modem. The audio is then resampled by the asterisk codec, so it doesn't have to be 16 bits. The mulaw and aulaw I believe are 13 bits between codecs.
The best thing to do is listen to the audio at the far end and see if it sounds like the signal being sent. If it is highly distorted, then experiment with different asterisk codecs, but don't use a vocoder type (like CELP, etc). I don't know how SLINEAR works across miles, but AU and MU work well for long ranges. ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2