Super SIM Connection Events on Event Streams

Currently, there are six types of event which may be emitted into the stream:

• Attachment Accepted
• Attachment Rejected
• Attachment Failed
• Data Session Started
• Data Session Updated
• Data Session Ended
• Data Session Failed

This flowchart shows when these events may be triggered once a device has powered up:

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Event type string: com.twilio.iot.supersim.connection.attachment.accepted

Your device successfully authenticated with a cellular network and is allowed to connect to it. This means:

• The Super SIM is ready or active.
• The network that your device is trying to connect to is allowed by the Network Access Profile used by the Super SIM's Fleet.
• The IMSI being used is allowed to connect to the network.

If your device is using a valid Super SIM APN (e.g., super) and the device is able to establish a data connection, a Data Session Started event will follow this event. If you receive repeated attachment.accepted events in quick succession, it may indicate that the device is unable to use data and is repeatedly restarting the attachment process.

This event may not be published every time your device connects. For instance, it will not be published if the device has previously authenticated with the network, which has cached the device's permission.

Event type string: com.twilio.iot.supersim.connection.attachment.rejected

Your device's attachment request was rejected by the network. The device was unable to connect.

Rejections can occur because:

• The Super SIM is still new or inactive.
• The network that your device is trying to connect to is blocked by the Network Access Profile used by the Super SIM's Fleet.
• The IMSI currently being used is not allowed to connect to the network.

To connect, your device will need to try a different network, use a different IMSI, or retry after the Network Access Profile used by the Super SIM's Fleet has been updated to allow the network.

Event type string: com.twilio.iot.supersim.connection.attachment.failed

Your device's attachment request failed for an unknown reason.

This event usually indicates a transient error which will resolve itself in time. When the device attempts to reconnect to the network, it may get a different result.

Event type string: com.twilio.iot.supersim.connection.data-session.started

Your device is connected to a network using a valid Super SIM APN, and can send and receive data.

Data session events will be published for traffic on both user APNs (e.g., super) and OTA APNs (e.g., ota.super) because all data used is billed and counts towards the Super SIM's data limit. However, data-session.started events will not indicate how much data was transferred by a device; this event only indicates that a data session has begun. To track data usage, subscribe to Data Session Updated events.

Event type string: com.twilio.iot.supersim.connection.data-session.updated

Your device has remained connected using a valid Super SIM APN, and can continue to send and receive data.

While the device remains connected, data-session.updated events will be published approximately every six minutes, with the first arriving approximately six minutes after the Data Session Started event. Each data-session.updated event will include the number of bytes that were sent to the device (the event's data_download property) and the number sent by the device (data_upload) between the data_session_update_start_time and the data_session_update_end_time.

Event type string: com.twilio.iot.supersim.connection.data-session.ended

Your device's data session has ended. The device can no longer send or receive data until a new data session is started. This event will include the amount of data that was sent to the device (data_download) and from the device (data_upload) since the most recent Data Session Updated event.

The data_session_start_time, data_session_end_time, data_session_data_download, data_session_data_upload, and data_session_data_total properties can give you a complete picture of the data session, telling you how long the device's data session was maintained and how much data was exchanged over it.

Event type string: com.twilio.iot.supersim.connection.data-session.failed

Your device's attempt to create or maintain a data session failed. The device can no longer send or receive data until a new data session is started.

The Super SIM events you receive are based on a common schema that defines the following properties. Some properties will not be present in every case: error will not be included if no error took place, and attachment-related events will not include data-related properties. The data_modifier property is only included if the Super SIM has exceeded its data limit. The location and imei properties will be omitted if Twilio didn't receive this information from the visited network.

The event's location property provides information about the placement of the cell tower to which the device was or is connected. This information is not guaranteed to be send by the network, so this property may be null.

The event's network property contains information about the visited cellular network that the device attempted to connect to or is connected to.

The event's error property will be null if no error occurred. Otherwise it contains the following information.

If you already have a number of devices deployed, you may quickly exceed the first 100,000 free events offered by Event Streams. For example, data-session.updated events are published every six minutes if your devices maintain a persistent connection, and can therefore exceed 7,000 events per device per month. We recommend you start your development work in a separate Twilio Subaccount or Project so you don't get charged for the events generated by all of your devices until you are ready.

You can transfer a Super SIM that is still in the new state to a subaccount by using this API request. If you wish to transfer a Super SIM in another state to a different Account (either a Subaccount or a Project), please open a support ticket. A Twilio Support Specialist will be able to help you get started.

To generate attachment.rejected events, you can put a Super SIM that is either new or inactive into your device. Alternatively, update your Fleet's Network Access Profile to block all of the networks in your country.

If you don't need to do near real-time usage billing or metering, you may be able to use data_session_data_upload, data_session_data_download, or data_session_data_total properties on data-session.ended events to understand how much data each of your devices are using without having to subscribe to data-session.updated events. These fields contain the cumulative amount of data exchanged by your device over the data session. This can reduce the number of events you have to receive and process by over 90%.