SMPP（short message peer to peer）协议是一个开放的消息转换协议；它定义了一系列操作的协议数据单元（PDUS）和当SMPP运行时ESMS应用系统与SMSC之间交换的数据格式。从而完成SMSC与ESMES（外部短消息实体）的信息交换。SMPP是基于SMSC与ESME之间的请求和响应协议数据单元的交换，每一个SMPP操作都由一个请求PDU和相应的一个响应PDU组成，并且这种交换是在TCP/IP或x．25网络连接之上的.-SMPP (short message peer to peer) protocol is an open protocol message transformation　It defines a series of operations protocol data unit (PDUS) and run-time when the SMPP SMSC ESMS exchanged between applications and data formats. Thus completing the SMSC and ESMES (External Short Message Entity) information exchange. SMPP SMSC and ESME based on requests and responses between the exchange of protocol data unit, each operation consists of a SMPP request PDU and the corresponding composition of a response PDU, and this exchange is in the TCP/IP or x. Over 25 network connection.