The Soracom User Console SIM Management page will display a session status indicator of Online or Offline for SIMs that are in Active status. When there is a cellular session currently in progress a a SIM will be listed as Online. Once the device terminates that session, it will be listed as Offline. This change occurs immediately in our backend systems but will not be reflected on the SIM Management page until the browser window is refreshed. Online and Offline statuses are not an indicator of a SIM's availability, or its capacity to establish a session.
Even if a device is powered on and can register with the network, it may not establish a session. This could be for several reasons, such as if the Access Point Name (APN) is not properly configured or if data roaming is disabled. Although the device may still be able to access some basic network functions, such as SMS services, it will appear offline in the SIM Management screen until it creates a session.
If a modem does not delete a cellular session before being powered down, the cellular session will remain open on the Soracom backend and the SIM will display as Online until the session times out. A session timeout will occur in a certain period.
Soracom's roaming partner carriers may also disconnect your sessions after a shorter period if there is no data sent by your device. The specific details of each partner carrier's timeout periods are not available, so you may need to determine these periods through your own testing.