ths procedure is iniciated when the called is a fixed analogic number and hook the call. The remote switch must send a Suspend msg in order to suspend the call. The the called number can reactivate the call and the remote switch must send a Resume message. In your swicths you must have a SUSPEND/RESUME timer (I,dont know witch TXXX ) usually 90 s in order to release the call if you dont receive RESUME msg (sometimes its happens) , cause you could have “infinite” call if Calling Number doesn,t release the call