gNB remote N3 port can no more be modified

Some recent GTP modification has hard-coded the remote port used for N3 interface, line 114 in openair2/E1AP/e1ap_setup.c: e1Setup->remotePortN3 = GTPV1_U_PORT_NUMBER; . Previously both remote and local ports used for N3 were set to the configurable parameter GNB_PORT_FOR_NGU.

This breaks setup where LTE and 5G cores are running on the same system. The easiest fix, consistent with previous behavior, is to modify line 114 to e1Setup->remotePortN3 = e1Setup->localPortN3 ;. Another proposal would be to use distinct parameters for N3 local and remote ports.