Question: What is the format of a Temporary Public User Identity for a Stand-alone Non-Public Network (SNPN) subscriber with an IMSI-based SUPI type?
Option 1: sip:<IMSI>@ims.mnc<MNC>.mcc< MCC>.3gppnetwork.org
Option 2: sip:<IMSI>@ims.nid<NID>.mnc<MNC>.mcc<MCC>.3gppnetwork.org
Option 3: sip:<IMSI>@ims.<MNC>.mcc<MCC>.nid<NID>.3gppnetwork.org
Option 4: sip:<IMSI>@ims.mnc<MNC>.mcc<MCC>.nid<NID>.3gppnetwork.org
Explanation: According to the specification, for an SNPN subscriber with an IMSI-based SUPI type, the temporary public user identity shall use the IMSI-based derivation and append nid<NID> of the SNPN in between the "ims." and "mnc<MNC>" labels. This matches Option 2.