How it Works
If the User Plane Function indicates the support of the feature UL or DL Buffering Control (UDBC), the SMF provides the buffering packet count IE in a BAR. The buffering count IE is created during a PFCP Session Establishment procedure or a PFCP Session Modification procedure. The SMF modifies it in a subsequent PFCP session modification request, "and" or "or" a PFCP Session Report Response message. The same BAR associates with all the FARs in a PFCP session to indicate that all service data flows in the PFCP session shares the same buffer in the UPF for the PFCP session. One BAR is created per PFCP session.