Cisco Systems, Inc.
Session and service/flow continuity

Abstract:

A Session Management Function (SMF) provides session and service continuity for a User Equipment (UE) transitioning between User Plane Functions (UPFs). The SMF establishes a first session between the first UPF and the UE using a first network address. The SMF determines that the UE transitions to the second UPF and establishes a second session between the second UPF and the UE using a second network address for new flows on the second session. The SMF queries the first UPF to determine any ongoing flows in the first session. The first UPF forwards packets in the ongoing flow(s) to the UE via the second UPF. The second UPF forwards packets in the ongoing flow(s) to the first UPF with the first network address. The SMF directs the second UPF to replace the first network address with the second network address in packets of a new flow for the UE.