Server disconnects

[djmad]

Version: 16.18 Multiplayer

If im playing at a multiplayer server, every time the server is saving the map, my clients looses the connection.

Test situation 1:
Server
-Port Forward (fortigate)
Internet
-NAT (Fortigate)
Client 1
-------------- Disconnect every 5 minutes

Test situation 2:
Server
-Port Forward (fortigate)
Internet
-NAT (Non Fortigate)
Client 2
-------------- No disconnect

Test situation 3:
Server
-VPN (fortigate)
Internet
-VPN (fortigate)
Client 1
-------------- no disconnects, but the same Internet lines as in Test 1


I narrowed it down, it seems to be an mistake in the NAT of my firewall which closes the connection if a save occures.
the problems startet with i thing version 15, because before i played for hours without disconnect.

as the Internet line is pretty stable (to the server in the 20ms range with no packetloss or duplicates at all) i think that there is some mistake in the udp implementation, or that a function has been added to the network stack, which the NAT does not understand and closes the connection.

It is now impossible to play longer as 5 minutes, because of autosaves or player connections on larger servers.

In every situation i instantly can reconnect and have full bandwidth aviable and can play lag-free