TS 33.128 rel-18 CR0750 - Reporting Alternative NSSAI
According to TS 23.501, the Network Slice Replacement feature is used to temporarily replace an S-NSSAI with an Alternative S-NSSAI when an S-NSSAI becomes unavailable or congested in the 5GC. 5GC protocols use specific information elements to include Alternative NSSAI to applicable messages. The current version of TS 33.128 doesn’t allow to report this information inside the (x)IRIs.