Message Handling

This section covers the PDUs responsible for sending, receiving, and managing SMS traffic between an ESME and the SMSC.

SubmitSm, SubmitMulti, and DataSm handle outbound message submission, supporting both single and multi-recipient delivery. DeliverSm is used by the SMSC to forward mobile-originated messages or delivery receipts to the ESME.

For message tracking and modification, PDUs like QuerySm, ReplaceSm, and CancelSm allow the ESME to query the status of submitted messages, replace their content, or cancel them altogether. Together, these classes represent the essential tools for message exchange over SMPP.