UPF2_in : (Z,A) -> UPF2 maps flow with SID UPF2_out: (U2::1, C1)(GW::SA:DA:TEID, S1; SL=2)(Z,A) ->H.Encaps.Red C1_out : (U2::1, S1)(GW::SA:DA:TEID, S1; SL=1)(Z,A) S1_out : (U2::1, GW::SA:DA:TEID)(Z,A) SRGW_out: (GW, gNB)(GTP: TEID=T)(Z,A) -> End.M.GTP4.E gNB_out : (Z,A)