A Delivery Report (DLR) is a message from an operator (also called SMSC for Short Message Service Center), that notifies you whether or not the message was delivered to the intended recipient. In other words, the delivery report shows the current status of the message that you submitted to the carrier.
Depending on the market and the operator, the delivery reports may be handset-based or network-based.
Handset-based delivery reports
The handset-based Delivery Reports are the most accurate, as it shows whether the recipient's phone actually received the SMS message or not.
After you forward the SMS message request to Messente, we'll forward the SMS message to the operator. The operator will let us know that they received the SMS message request and will try to forward the SMS message to the recipient's phone.
Once the operator has managed to make a connection between its cell tower and the recipient's phone, the SMS data will be forwarded to the phone. Once all the data has been forwarded to the phone, the phone will respond to the operator that it received all the information required in order to display the SMS message to the recipient. Once the operator receives the confirmation from the phone, the DLR of the SMS message will be marked as Delivered and forwarded to us, after which Messente will forward the DLR to you.
Network-based delivery reports
Some countries and operators have network-based Delivery Reports, also called SMSC-based Delivery Reports, which do not show whether the SMS message reached the recipient.
After you forward the SMS message request to Messente, and we forward the SMS message to the operator, the operator will respond immediately with a final DLR. If the operator will attempt to deliver the SMS message to the client, the delivery report will be marked as Delivered, but the operator will be unable to provide confirmation of whether the SMS message actually reaches the phone. Due to the previous, the given Delivery Report system will only let you know if the SMS message has reached the operator and whether the operator will make an attempt to deliver it.
All Viber delivery reports are handset-based, with the availability to provide information on whether the recipient received your Viber message or also opened your Viber message as well.