ESME,日本歌手，演唱的歌曲有《Morning Call》，收入在专辑《術ノ穴Presents「Hello!!!Vol.7」》中，ESME always connects to SMSC using a TCP/IP, X.25, etc. and then binds for the service it needs from SMSC.

For SMPP it can bind for Receiving only service, Transmitting only service or both (Transceiver service). Before SMPP 3.4 it was required to have two different connections, one for Transmitting and the other one for Receiving. Starting with SMPP 3.4 a Tranceiver connection is enough for both.

The relation between ESME and SMSC is somehow a master-slave relation because SMSC is providing services to ESME, and usually ESME just uses these services from SMSC. One of the functions of the SMSC is to store and forward the messages while the ESME doesn't have this function. When a message is sent by an ESME to SMSC towards its destination, this message may stay in a SMSC queue until its destination will become available. During this time the ESME has the options to cancel the message in queue, to replace it or to check its status. ESME can also send a message to multiple destinations which will be handled by SMSC