to be called right after a call to pri_hangup() that sends the DISCONNECT message. Libpri is not going to do this. There are two places in Asterisk (v1.8) that will do this. However, the code that does it is dealing with a link down situation when T309 is not enabled. For the libpri version you mention, this will never happen since T309 is always enabled. Which version of Asterisk are you using? Richard