Method and apparatus for handling non-integrity protected reject messages in non-public networks

1. An apparatus comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to at least:

cause storage of a list of subscriber data, wherein entries in the list of subscriber data comprise subscriber data used to access a standalone non-public network (SNPN);

maintain one or more lists of forbidden SNPNs and one or more SNPN-specific attempt counters; and

in an instance in which an entry of the list of subscriber data is reconfigured or removed, determine whether the identity of the SNPN associated with the reconfigured or removed entry should be removed from the one or more lists of forbidden SNPNs based on the one or more SNPN-specific attempt counters.

2. The apparatus of claim 1 , wherein said one or more lists of forbidden SNPNs comprises one or more of: a list of permanently forbidden SNPNs, a list of temporarily forbidden SNPNs, a list of permanently forbidden SNPNs for non-3rd Generation Partnership Project (non-3GPP) access, or a list of temporarily forbidden SNPNs for non-3GPP access.

3. The apparatus of claim 1 , wherein said one or more SNPN-specific attempt counters comprises one or more of: a SNPN-specific attempt counter for 3rd Generation Partnership Project (3GPP) access or a SNPN-specific attempt counter for non-3GPP access.

4. The apparatus of claim 1 , wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to at least:

receive, from a network function in a SNPN, a non-integrity-protected reject message, indicating that the entry used to access the SNPN is invalid;

upon receipt of the reject message, start a timer; and

upon expiration of the timer, determine whether the entry used to access the SNPN should be set to valid.

5. The apparatus of claim 4 , wherein the timer is a 3rd Generation Partnership Project (3GPP) timer T3247.

6. A method comprising:

causing storage of a list of subscriber data, wherein entries in the list of subscriber data comprise subscriber data used to access a standalone non-public network (SNPN);

maintaining one or more lists of forbidden SNPNs and one or more SNPN-specific attempt counters; and

in an instance in which an entry of the list of subscriber data is reconfigured or removed, determining whether the identity of the SNPN associated with the reconfigured or removed entry should be removed from the one or more lists of forbidden SNPNs based on the one or more SNPN-specific attempt counters.

7. The method of claim 6 , wherein said one or more lists of forbidden SNPNs comprises one or more of: a list of permanently forbidden SNPNs, a list of temporarily forbidden SNPNs, a list of permanently forbidden SNPNs for non-3rd Generation Partnership Project (non-3GPP) access, or a list of temporarily forbidden SNPNs for non-3GPP access.

8. The method of claim 6 , wherein said one or more SNPN-specific attempt counters comprises one or more of: a SNPN-specific attempt counter for 3GPP access or a SNPN-specific attempt counter for non-3GPP access.

9. The method of claim 6 , further comprising:

receive, from a network function in a SNPN, a non-integrity-protected reject message, indicating that the entry used to access the SNPN is invalid;

upon receipt of the reject message, start a timer; and

upon expiration of the timer, determine whether the entry used to access the SNPN should be set to valid.

10. The method of claim 9 , wherein the timer is a 3rd Generation Partnership Project (3GPP) timer T3247.

11. A non-transitory computer readable medium including program code which, when executed, causes operations comprising:

causing storage of a list of subscriber data, wherein entries in the list of subscriber data comprise subscriber data used to access a standalone non-public network (SNPN);

maintaining one or more lists of forbidden SNPNs and one or more SNPN-specific attempt counters; and

in an instance in which an entry of the list of subscriber data is reconfigured or removed, determining whether the identity of the SNPN associated with the reconfigured or removed entry should be removed from the one or more lists of forbidden SNPNs based on the one or more SNPN-specific attempt counters.

12. The non-transitory computer readable medium of claim 11 , wherein said one or more lists of forbidden SNPNs comprises one or more of: a list of permanently forbidden SNPNs, a list of temporarily forbidden SNPNs, a list of permanently forbidden SNPNs for non-3rd Generation Partnership Project (non-3GPP) access, or a list of temporarily forbidden SNPNs for non-3GPP access.

13. The non-transitory computer readable medium of claim 11 , wherein said one or more SNPN-specific attempt counters comprises one or more of: a SNPN-specific attempt counter for 3rd Generation Partnership Project (3GPP) access or a SNPN-specific attempt counter for non-3GPP access.

14. The non-transitory computer readable medium of claim 11 , wherein the program code which, when executed, further causes operations comprising:

receiving, from a network function in a SNPN, a non-integrity-protected reject message, indicating that the entry used to access the SNPN is invalid;

upon receipt of the reject message, starting a timer; and

upon expiration of the timer, determining whether the entry used to access the SNPN should be set to valid.

15. The non-transitory computer readable medium of claim 11 , wherein the timer is a 3rd Generation Partnership Project (3GPP) timer T3247.