This feature passes ETSI AOC-S, AOC-D, and AOC-E message information to
the upper layer (i.e. Asterisk) for processing.
Relevant specification: EN 300 182
Consideration was made for the possible future addition of Q.SIG AOC
support (ECMA-212) with the events passed to the upper layer.
Review: https://reviewboard.asterisk.org/r/538/
git-svn-id: https://origsvn.digium.com/svn/libpri/branches/1.4@1737 2fbb986a-6c06-0410-b554-c9c1f0a7f128
