Internet protocol multimedia subsystem support for stand-alone non-public networks

A method implemented in a proxy-call session control function, P-CSCF, node, the method comprising:

• receiving an Internet Protocol, IP, Multimedia Subsystem, IMS, registration request from a user equipment, UE;
• as a result of receiving the IMS registration request, subscribing to be notified of a Public Land Mobile Network, PLMN, identifier, ID, and a network identifier, NID, a combination of the PLMN ID and the NID identifying a standalone non-public network, SNPN, associated with the UE;
• as a result of the subscription, receiving a notification including the PLMN ID and the NID identifying the SNPN associated with the UE;
• and
• sending the received PLMN ID and the NID to a network node.

A network node comprising a proxy-call session control function, P-CSCF, at least one processor and computer program instructions executable by the processor to cause the network node to:

• receive an Internet Protocol, IP, Multimedia Subsystem, IMS, registration request from a user equipment, UE;
• as a result of receiving the IMS registration request, subscribe to be notified of a Public Land Mobile Network, PLMN, identifier, ID, and a network identifier, NID, a combination of the PLMN ID and the NID identifying a standalone non-public network, SNPN, associated with the UE;
• as a result of the subscription, receive a notification including the PLMN ID and the NID identifying the SNPN associated with the UE;
• and
• send the received PLMN ID and the NID to a network node.