[SR-Users] Call Control Behavior

Hi, My question concerns Call Control. When a SIP call's timer ends, Call Control uses dlg_end_dlg MI command of the dialog module to send a BYE to the UA. Can I intercept the BYE message, drop it, change it and send instead an INVITE or a REDIRECT using (maybe) the UAC module? The INVITE/REDIRECT would connect the UA to a media gateway to announce a message when the session ends. Any ideas? This also leads to thoughts on accounting and rating. In the case of sending and INVITE, the rating of the call becomes inaccurate since there's no BYE when the call ends, but only after the media gateway's announcement ends. In the case of a REDIRECT, the UA sends a BYE to the established call before the INVITE to the media gateway, and thus rating remains totally accurate. What do you think? Thanks RA