How do i confirm delivery of an SMS message ?

[Leon]

You can check if a message was delivered by requesting a delivery receipt. This method can be used when sending SMS messages using SMPP or GSM.

GSM:

You have to set the 'TP-SRR' flag in the SMS PDU. When this bit is set, the SMSC will send a delivery report PDU back to your GSM device.

SMPP:

Set the 'registered_delivery' field to 1. When the message has reached its final state, error or success, the SMPP provider will send back a delivery receipt in the form of a 'deliver_sm' message.

It is also possible to query the state of messages by using the 'query_sm' command. This is a bad alternative because of the bandwidth consumed, and you should not use it.

For more info about SMPP delivery receipt please see:

http://www.smssolutions.net/tutorials/smpp/smppdeliveryreports