[Solved?] Connection problems - Waves disconnect client.

[OpT1mUs]

I tried playing AI war with my friend, we used hamachi at first but then switched to direct ip connect. The problem is, when ever a new wave of AI units comes trough the wormhole he gets dc-ed (waiting for player) at the exact same moment and when he tries to reconnect he gets stuck on 99.5% sync. Every time.
Is this a known issue and is there a solution?

[x4000]

Hi there,

Sorry to hear about your troubles.  This is not a known issue per se, but it sounds like the exact same problem as from this thread:  http://arcengames.com/forums/index.php/topic,2023.0.html

Just with a different trigger.  But, the basic problem I think is that when too much data is sent, messages are going into a lost state and the network library is not recovering. 

1. If you could check on the client and the host machines to make sure there are no error messages logged (in the Game Data Location directory, which may be different on each machine, but which you can find via the Settings window in the game).  This would be something like NetworkClientErrors.txt, or ClientRecievingDataExceptions.txt, or something along those lines with an extension of txt.  If you find any of those, if you could please post them, that would help me see if there is potentially an issue in the network library -- however, I've been talking with the network library author (this library is used in many games), and this seems unlikely (but it's good to check).

1.a. If you are playing on vanilla 2.000 version, you probably have some unrelated ClientRecievingDataExceptions logged, but go ahead and post them so that I can make sure those are not relevant.  The latest prerelease, 2.001B includes some networking fixes that should fix the reconnect issue that you were having (that 99.5 sync issue is something that affects some people in 2.0 -- there is a workaround for that if you stay on 2.0, but it's simpler and better just to update to 2.001B).

2. Most likely the root cause here, as I noted on the other thread I linked to, is a bad network driver on one of the two machines, or some router firmware that is causing some sort of packet loss when it gets too much data at once.  I'd suggest seeing if you can update the network drivers first, and the router firmware second, as the most likely solutions to this issue.

3. If you want to do the Shift+F3 thing (described in the other thread) to get more information on what exactly is happening, if the above two items don't hold a solution for you, that would probably be the next step.  But I expect that either 1 or 2 above, most likely 2, is going to be the solution.  There are hundreds of people playing the game in co-op without this issue, and the best guess we have as to a solution for this so far (since the other thread is not yet reported as resolved, it is still just a guess) is that there is a lower-level network issue at play here (driver/router), unless this is just some sort of very edge case bug in the network library itself.

Hope that helps!

[OpT1mUs]

Apparently friend I played did forward his ports, after he did that and hosted we played normally without disconnects.
The thing is, before , I was the host, and afaik only host needs ports forwarded, so why did we have problems in the first place?

Even if it remains a mystery, I'm glad we can finally play normally

[x4000]

Apparently friend I played did forward his ports, after he did that and hosted we played normally without disconnects.
The thing is, before , I was the host, and afaik only host needs ports forwarded, so why did we have problems in the first place?

Even if it remains a mystery, I'm glad we can finally play normally

That is very odd, only the host should need port forwarding.  When you play with Hamachi, then no port forwarding would matter at all.  I would still suspect that there is something odd with one of the routers or NICs, but I'm glad that your solution is apparently bypassing the issue (not causing it to get triggered anymore)!

[x4000]

To update on this, we found a solution to this problem via another thread (http://arcengames.com/forums/index.php/topic,2023.0.html)

The problem was basically an incompatible MTU with certain router/ISP combinations.  This is the sort of thing that if an ISP and a router have certain unusual settings, then they would potentially fragment data and cause both bad performance and this sort of issue on large data transfer.  This is why so few people saw the issue, and why no exceptions were being thrown in the game itself -- the data was getting to the router, most likely, but not making it to the ISP.

The solution was for the game to start using a slightly smaller MTU (1400 instead of 1459), to insure that it should be compatible with all possible router/ISP combinations.  The latest prereleases have that new lower MTU in them: 
http://arcengames.com/forums/index.php/topic,2321.msg14555.html#msg14555

Hope that works for you, as well!