In various embodiments, a corpus of codecs may be correlated with different, partially overlapping ranges of transmission characteristics. As channel conditions degrade or improve, the system may select a new codec with which to continue the connection based upon the corresponding overlapping range. Codecs may not be switched immediately when the transmission characteristics enter overlapping ranges, to avoid degrading the user's experience. If the characteristics remain in the overlap, or manifest a likely progression toward another region, then the transition may be effected.