Cellular Network Infrastructure » EPC - Evolved Packet Core » osmo-ePDG - VoWifi Evolved Packet Data Gateway

Currently traffic from 1 UE to another UE on the same epdg is blocked by the firewall.
The root cause is that the traffic is not forwarded into the gtp interface towards the PGW.
The problem lies in the xfrm, which applies.

So far there might be 2 options:
a) try to use a VTI interface
b) try to add fwmark to the xfrm rule so it only applies for traffic which comes out of the gtp (which got itself marked by nftables).