DLR – delivery report

Delivery Report

Delivery report (DLR) is a feature provided for MT SMS, informing the Sender of the current status of the message sent. There are various types of  DLRs, varying from the SMSC DLRs, handset reports or simple bind acks. All of those are provided to give the Sender an opportunity of following up on all the MT SMS sent and catch on any issues in the delivery.

All users of SureM service can receive delivery reports for the message they send. We provide both get/post method in passing on the delivery reports to the clients.

There are two types of delivery reports :

  • Handset acknowledgment
    This report will give the clients the exact information whether the target handset has received the messages or not.
  • System delivery report
    This report will give the clients the notification of the transmission of the messages to the SMSC

Whether you choose SMPP, HTTP or any other type of system integration, we can provide DLRs for all message sent by the clients in real time.

If you have any technical inquires, please contact us at sureminternational@gmail.com



Auto-Calling System (ACS)

Auto-Calling System (ACS) – a type of voice call service, automatically dialing the end user and playing the provided record of the message.

ACS service is widely used :

  1. To cover the areas, where SMS reception can not be guaranteed
  2. When the end user is in roaming
  3. For users with disabilities, preventing them to read the messages

In general, ACS is a good way to improve delivery rates if used in combination with SMS.

Below you may see the flow for ACS service at SureM


Benefits of ACS

  • A subscriber can still receive the verification code when a text message cannot be delivered.
  • A subscriber is given a choice to make to receive a voice call instead of a text message.
  • Speech can be recorded in different languages to suit the recipients that makes it much easier and more convenient for the recipients.

Korean LMS : similar to concatenated SMS?

What happens when I send a really long message through A2P line? Is it delivered in one piece to cell phone? Or is it cut into parts and delivered as multiple SMS? If so is the order correct?

Every company that needs to send long messages for whichever purpose faces these questions. And truth is – depending on a lot of factors the answer will be different.

Not all countries and networks support the so-called Concatenated SMS (C-SMS, Concats).

Concatenated SMS – a service, allowing delivery of SMS longer than the standard 160 GSM characters in one piece to the handset.

Number of SMS

GSM characters

Unicode characters

1 standard SMS



2 concatenated SMS



3 concatenated SMS



4 concatenated SMS



Basically, the process involves breaking the message first into multiple parts and then reattached together in the correct order into one message when delivered to the handset.

There is no fixed limit for concatenated SMS, depending on the device capacity it may vary. As for the destination and network – here’s the catch. CDMA networks do not support concatenation. So the messages will be delivered in parts to the handset, which is why for some countries SMS Hub providers always mention that they can not guarantee 100% delivery of the messages over 160 bytes (e.g. USA).

Another case where concatenation is not supported – South Korea. South Korea has a unique service called LMS (Long Message Service). Unlike other countries, for A2P providers Korean message length limit is different :

Message type

GSM characters

Unicode characters

1 standard SMS



1 standard LMS



From technical side, the process does not involve concatenation, the message is delivered in one whole piece from the Sender all the way to the handset.

The biggest difference and the benefit of LMS over C-SMS is it’s price. While A2P SMS providers charge the total price as SMS price x (Num. of parts in C-SMS ), Korean providers offer single pricing for LMS. It means, that no matter how long the message you sent is, 200 or 2000 bytes – you still pay the same price, while with C-SMS for really long promotional text you might have to pay 10 x SMS price.