open5gs-smfd version 2.4.2 requires this IE to be present:
[smf] INFO: [Added] Number of SMF-UEs is now 1 (../src/smf/context.c:820)
[smf] INFO: [Added] Number of SMF-Sessions is now 1 (../src/smf/context.c:2610)
[smf] ERROR: No Serving Network (../src/smf/s5c-handler.c:101)
[smf] ERROR: No Data in Serving Network (../src/smf/s5c-handler.c:105)
[smf] ERROR: Invalid Len[0] in Serving Network (../src/smf/s5c-handler.c:110)
Change-Id: Idf6d147cc4a37996ee4ae6de18158b0e140d9db6
Related: SYS#5602
this includes a GTPv2_CodecPort (for the usual transcoding)
as wella as an empty GTPv2_PrivateExtensions.ttcn without which
the TITAN GTPv2 ProtocolModule won't compile.
Change-Id: I1c1b8409077103dd4e64e467d21d33d8c9c4ac95