When using Digi devices with cellular modems, e.g. Digi cellular routers, it's important to understand that they are 'at the mercy' of the SIM card inserted in the device, and different SIM cards have different capabilities.
Basic SIM cards simply provide the Digi device with Internet access. These are called mobile originated SIMs and provide outbound only communications. If you have equipment attached to a Digi cellular-capable device and it needs to reach some server over the Internet 'cloud', a basic SIM may be sufficient.
Higher tier SIM cards provide bi-directional Internet access, these are called mobile terminated. A Digi device with this type of SIM would be expected to have a Public mobile IP address that's reachable over the Internet. This type of SIM may provide either a Static or Dynamic mobile IP address, it depends on the SIM and Access Point Name or APN.
Think of an APN like a wifi SSID, it's a string of letters and/or numbers that specifies the network you wish the Digi device be on. All SIMs are only allowed to use certain APNs.
If you need to remotely access equipment attached to a Digi cellular-capable device over the Internet 'cloud', a mobile terminated SIM may be sufficient.
Specialty SIM cards also exist that provide access to your company's private network, these use Private APNs.
Talk to the SIM provider (which may or may not be Digi) to understand what type of SIM card you have, to understand its capabilities and limitations.
Last updated:
Jan 01, 2024