This creatable/settable string configures the Access Point Name (APN) for a given data profile, a value the service provider supplies to identify which network/gateway the device should connect through. An admin must set this correctly for each profile since an incorrect APN is one of the most common reasons a GSM data session fails to establish even when radio signal is strong. For example, if a carrier issues a new APN string for IoT-specific data plans, the admin would update this profile object to the new APN to keep data sessions working.