SMPP is an open, industry standard protocol designed to provide a flexible data communications interface for transfer of short message data between a Message Center, such as a Short Message Service Centre (SMSC), GSM Unstructured Supplementary Services Data (USSD) Server or other type of Message Center and a SMS application system, such as a WAP Proxy Server, EMail Gateway or other Messaging Gateway. This test suite is intended for testing Short Messages delivered over Short Message Peer to Peer (SMPP) protocol. The test suite does not test SMPP protocol, only SMS user data delivered over SMPP. For testing SMPP protocol, SMPP Server Test Suite may be used.