UE_out  : (A,Z)
gNB_out : (gNB, U1::1) (A,Z)     -> H.Encaps.Red <U1::1>
UPF1_out: (gNB, U2::1) (A,Z)     -> End.MAP
UPF2_out: (A,Z)                  -> End.DT4 or End.DT6