Routing in SMSC For ESME
An example of how the routing can be done at SMSC level, but not mandatory as this depends a lot on the implementation of SMSC and the way the connection inside the SMSC is between routing part of the SMSC and SMPP interface can be as below: During the service agreement between ESME and service provider(SMSC side) one unique short code will be allocated to ESME. At the SMSC end smpp server will have list of all ESME address and active connection. When you send any message to short code, messages first comes to SMSC, SMSC decodes it according to GSM 3.4 spec, then one of module in SMSC checks the destination address if it is short code then that module routes messages to SMPP server part of the SMSC. Now SMPP server will have all active connection, according to destination address it selects the ESME - SMPP server connection object, that object will be responsible to encode message according to SMPP protocol and forward to ESME.
Communication between SMSC and ESME can be on either SMPP or HTTP. If you have SMPP account, you could connect to the SMPP IP+Port on TCPIP and the SMPP will push MOs to ESME on SMPP connection. and ESME will push MTs on the same connection in reverse. If you have HTTP account with the operators SMSC, then the SMSC will post the MO onto an URL given by you and to push MTs SMSC will give you on URL.
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