Section: 28.3.2.2.4 Visited Country FQDN for N3IWF
Content: 28.3.2.2.4.1 General The Visited Country FQDN for N3IWF, used by a roaming UE to determine whether the visited country mandates the selection of an N3IWF in this country, shall be constructed as described below. The Visited Country FQDN shall contain a MCC that uniquely identifies the country in which the UE is located. The Visited Country FQDN is composed of seven labels. The last three labels shall be "pub.3gppnetwork.org". The fourth label shall be "visited-country". The third label shall uniquely identify the MCC of the visited country. The first and second labels shall be "n3iwf.5gc". The resulting Visited Country FQDN of N3IWF shall be constructed as follows: "n3iwf.5gc.mcc<MCC>.visited-country.pub.3gppnetwork.org" The <MCC> coding used in this FQDN shall be: - <MCC> = 3 digits As an example, the Visited Country FQDN for MCC 345 is coded in the DNS as: "n3iwf.5gc.mcc345.visited-country.pub.3gppnetwork.org". 28.3.2.2.4.2 Visited Country Emergency N3IWF FQDN The Visited Country Emergency N3IWF FQDN, used by a roaming UE shall be constructed as specified for the Visited Country FQDN for N3IWF in clause 28.3.2.2.4.1, with the addition of the label "sos" before the labels "n3iwf.5gc". The resulting Visited Country Emergency N3IWF FQDN shall be constructed as follows: "sos.n3iwf.5gc.mcc<MCC>.visited-country.pub.3gppnetwork.org" As an example, the Visited Country FQDN for MCC 345 is coded in the DNS as: "sos.n3iwf.5gc.mcc345.visited-country.pub.3gppnetwork.org". 28.3.2.2.4.3 Visited Country FQDN for N3IWF supporting Onboarding UE onboarding for access to SNPN services is specified in clause 5.30.2.12 of 3GPP TS 23.501[ System architecture for the 5G System (5GS) ]  [119]. Visited Country FQDN for N3IWF supporting Onboarding encoding is constructed by adding a label "onboarding" to Visited Country FQDN for N3IWF FQDN (see clause 28.3.2.2.4.1), indicating that the N3IWF identified by the N3IWF identifier in the DNS response shall supports onboarding. Visited Country FQDN for N3IWF supporting Onboarding is constructed as follows: "onboarding.n3iwf.5gc.mcc<MCC>.visited-country. pub.3gppnetwork.org" As an example, the Visited Country FQDN for N3IWF supporting Onboarding for MCC 345, is coded in the DNS as: "onboarding.n3iwf.5gc.mcc345.visited-country.pub.3gppnetwork.org".