AST is for Associate Set Assignment, usually used to include phone info/control to cti applications, in our case used for voice recording with AST set to the Key number of the dn we want to monitor and IAPG set to 1 to put the info onto the cti feed
SIP - not sure of specifiaclly but would say that it's related to SIP trunks and sip cti integration
It's not getting any smarter out there. You have to come to terms with stupidity, and make it work for you.