Question: What is the correct step to derive an Access Point Name Fully Qualified Domain Name (APN-FQDN) from an Access Point Name (APN) that uses a default APN Operator Identifier (APN-OI)?
Option 1: Insert "apn.epc." between the APN-NI and the default APN-OI, and replace ".gprs" with ".3gppnetwork.org"
Option 2: Replace the entire APN-NI with "apn.epc.", and append the default APN-OI without modifications
Option 3: Prepend "mnc<MNC>." to the APN-NI, and replace ".gprs" in the APN-OI with ".3gppnetwork.org"
Option 4: Append ".3gppnetwork.org" directly to the APN-NI without any other modifications
Explanation: When deriving an APN-FQDN from an APN that uses a default APN-OI, the correct process involves inserting "apn.epc." between the APN Network Identifier (APN-NI) and the default APN Operator Identifier (APN-OI), and then replacing the ".gprs" label at the end of the default APN-OI with ".3gppnetwork.org". This ensures a standardized and correct transformation into an FQDN format.