Section: 19.4.2.2.1 Structure
Content: The Access Point Name FQDN (APN-FQDN) is derived from an APN as follows. The APN consists of an APN Network Identifier (APN-NI) and an APN Operator Identifier (APN-OI), which are as defined in clause 9.1.1 and 9.1.2 of the present document. If an APN is constructed using the default APN-OI, the APN-FQDN shall be obtained from the APN by inserting the labels "apn.epc." between the APN-NI and the default APN - OI, and by replacing the label ".gprs" at the end of the default APN-OI with the labels ".3gppnetwork.org". EXAMPLE1: For an APN of internet.mnc015.mcc234.gprs, the derived APN-FQDN is internet.apn.epc.mnc015.mcc234.3gppnetwork.org If an APN is constructed using the APN-OI Replacement field (as defined in 3GPP TS 23.060[ General Packet Radio Service (GPRS); Service description; Stage 2 ]  [3] and 3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [72]), the APN-FQDN shall be obtained from the APN by inserting the labels "apn.epc." between the label "mnc<MNC>" and its preceding label, and by replacing the label ".gprs" at the end of the APN-OI Replacement field with the labels ".3gppnetwork.org". EXAMPLE 2: If an APN-OI Replacement field is province1.mnc015.mcc234.gprs and an APN-NI is internet, the derived APN-FQDN is internet. province1.apn.epc.mnc015.mcc234.3gppnetwork.org