Subject: app_mixmonitor
Master-Only: true

In Asterisk 13.29, a new option flag was added to MixMonitor (the 'S'
option) that when combined with the r() or t() options would inject
silence into these files if audio was going to be written to one and
not that other. This allowed the files specified by r() and t() to
subsequently be mixed outside of Asterisk and be appropriately
synchronized. This behavior is now the default, and a new option has
been added to disable this behavior if desired (the 'n' option).
