Short Message Peer-to-Peer

Short Message Peer-to-Peer (SMPP) in the telecommunications industry is an open, industry standard protocol designed to provide a flexible data communication interface for the transfer of short message data between External Short Messaging Entities (ESMEs), Routing Entities (REs) and SMSC. SMPP is often used to allow third parties (e.g. value-added service providers like news organizations) to submit messages, often in bulk, but it may be used for SMS peering as well.

Source: Wikipedia — Short Message Peer-to-Peer (CC BY-SA 4.0)