UPF1_in : (Z,A)                             ->UPF1 maps the flow w/
                                              SID list <C1,S1, gNB>
UPF1_out: (U1::1, C1)(gNB::1, S1; SL=2)(Z,A)->H.Encaps.Red
C1_out  : (U1::1, S1)(gNB::1, S1; SL=1)(Z,A)
S1_out  : (U1::1, gNB::1)(Z,A)              ->End with PSP
gNB_out : (Z,A)                             ->End.DX4/End.DX6/End.DX2