When will my device receive a Mobile Terminated (MT) SMS?
What is an SMS MT?
There are two kinds of SMS:
Mobile Originated (MO) SMS when a device sends a message
Mobile Terminated (MT) SMS when a device receives a message
MO and MT SMS will appear and be charged differently, however, you can enable or disable SMS MO or MT for your endpoints in the SAP IoT Connect 365 UI.
Log in to the UI, select the Service Profiles option from the top menu, select the service profile you are interested in and click the Basic Configuration tab:
Not all SMS MT will appear in the SAP IoT Connect 365 UI as our SMS Centre (SMSC) does not handle messages sent by devices using other providers (Vodafone or Deutsche Telecom for example). This is the difference between A2P and P2P SMS.
A2P vs P2P SMS
A2P (Application to Person) - One-way SMS to which recipients are not expected to reply. A2P messaging includes but is not limited to marketing messages, appointment reminders, notifications and pin codes. A2P SMS MT, always go through our SMSC and are therefore registered in the UI.
P2P (Person to Person) – two-way messaging like when you use your phone to send a text message to a friend. P2P SMS MT go through an SMSC that SAP IoT Connect 365 does not control. We therefore cannot know if a message has been received and cannot display any information in the UI.
To enable or disable P2P or A2P SMS, log in to the SAP IoT Connect 365 UI, select the Service Profiles option from the top menu, select the service profile you are interested in and click the SMS tab:
To update some devices, for example, GPS trackers, an Over The Air (OTA) update is sometimes necessary. Those happen by SMS and will be considered as A2P SMS MT, that is, they will be handled by SAP IoT Connect 365's SMSC and displayed in the UI. Such devices are not always connected to the network though, they sometimes only connect once a day. For such devices, SMS Buffering is implemented.
SMS MT Buffering
In normal cases, our SMSC will try to periodically deliver SMS MT to endpoints. Besides those attempts, our SMSC will also be notified by the visited network, when a device is ready to receive a SMS. At this point, the SAP IoT Connect 365 SMS centre will try to send the message again directly. Thanks to this "Buffered SMS-MT" tool, our SMSC can deliver messages to connected devices at the right time. Note that our SMSC will only buffer SMS 24 hours. For the SMS MT Buffering function to work, you need to enable SMS MT and A2P SMS in the service profile.
To check in SMS Buffering is working, log in to the SAP IoT Connect 365 UI, select the Endpoints option from the top menu, select the endpoint you are interested in and click the SMS tab:
This shows you the SMS MT received by your device. When an SMS if buffered, it will appear yellow as you can see in the screenshot above.