The CC recall

The calling party will make its recall to the same extension that was dialed. Asterisk will provide a channel variable, CC_INTERFACES, to be used as an argument to the Dial application for CC recalls. It is strongly recommended that you use this channel variable during a CC recall. Listed are two reasons:

Note that even if your call gets routed through local channels, the CC_INTERFACES variable will be populated with the appropriate values for that specific extension. When the called parties are dialed, it is expected that a called party will answer, since Asterisk had previously determined that the party was available. However, it is possible that the called party may choose not to respond to the call, or he could have become busy again. In such a situation, the calling party must re-request CC if he wishes to still be alerted when the calling party has become available.

lmadsen 2010-10-21