How Delivery Receipt is posted while sending messages from SMSC to ESME

Question

I'm having a confusion on how to receive delivery receipt from ESME to SMSC?

For Example : If i terminate an Message from SMSC to ESME,then how can ESME sends delivery receipt for the corresponding Message received from SMSC.

If SUBMIT_SM is used for sending the delivery receipt to SMSC,then How can the SMSC differentiates a Normal Text Message and a Delivery Receipt from ESME?

Thanks in advance. :)

Answer 1

Within the SUBMIT_SM message, there is a field called "esm_class" which will allow you to send a delivery receipt to the SMSC. From the SMPP specification 5.0 page 125 the field contains a number of flags that can be set depending upon what kind of message you are sending. The flags for delivery receipts are below.

• xx0001xx Short Message contains MC Delivery Receipt Message Type (bits 2 and 5)
• xx1000xx Short Message contains Intermediate Delivery Notification
• xx0010xx Short Message contains Delivery Acknowledgement

I believe that you will need to send an Intermediate Delivery Notification then a Delivery Acknowledgement message to the SMSC. The Intermediate Delivery Notification is probably optional.

Note that this is highly dependent on what is implemented in the SMSC. It's possible that the SMSC does not even handle these delivery receipts and perhaps will assume that the SMS has been delivered when you send the SUBMIT_SM_RESP in response to the SUBMIT_SM, or perhaps as soon as the SUBMIT_SM message is sent. You will need to test what happens.