Hello list, I wonder if someone could give me a hint on how I go about working out when applications can be used after bridging A & B legs? I have spent a fair amount of time googling the list, but not yet stumbled into how it is determined if an application can be invoked mid call. Some can and some can¹t but I have yet to work out the logic that decides this? The application in question is ³drop_dtmf² but the question is more general. Also how does one work out if it should work with SIP-Info instead of 2833? Thanks Magnus