The Interworking MSC of the SMSC, on receipt of the MAP mo-ForwardSM message, passes the SMS-PP Application Protocol Data Unit (APDU) containing the text message to the actual Service Centre (SC) of the SMSC for storing, and subsequent "forwarding" (delivery) to the destination address and the SC returns an acknowledgement indicating success or failure. On receipt of this submission status from the Service Centre, the Interworking MSC will send an appropriate indication back to the VMSC/SGSN of the sending subscriber. The message submission status is then forwarded, over the air interface, to the subscriber's handset.