Question: In a roaming scenario, how should a UE construct the Operator Identifier based N3IWF FQDN to utilize services from either the Visited PLMN (VPLMN) or the Home PLMN (HPLMN)?
Option 1: Using only the MNC and MCC of the HPLMN for both VPLMN and HPLMN services.
Option 2: Randomly selecting between the MNC and MCC of the VPLMN or the HPLMN for each service access.
Option 3: Constructing the N3IWF FQDN with the MNC and MCC of the VPLMN for VPLMN services and the MNC and MCC of the HPLMN for HPLMN services.
Option 4: Omitting the MNC and MCC in roaming scenarios, using only "n3iwf.5gc.pub.3gppnetwork.org".
Explanation: To ensure seamless service utilization in a roaming context, the UE must accurately identify the network it is interacting with. Using the MNC and MCC of the respective PLMN for each type of service guarantees correct routing and authentication, aligning with the principle of unique network identification for N3IWF FQDN construction.