Can my device go online without configuring the APN?

When your sim attaches to a network, our HLR pushes the list of allowed APNs (during ISD) to the visited network's SGSN, and some SGSNs are intelligent enough to use this info in case a wrong or no APN is configured in the device. 

At the moment, we know of three operators which we confirmed to have this feature in their SGSN. 

KPN, Netherlands
Telekom, Germany
Vodafone, Australia

This feature is solely dependent on the visited network infrastructure so such functionality is not guaranteed to work by EMnify. It is still always essential that the correct APN must be configured in the device for the data session to work. 

Relate Articles:

Manual APN Configuration

Programming APN Settings into a GSM Module via AT command

Configuring the APN on a GPS Tracker TK104 family