[plug] [OT] Wierd problem

[Ben Jensz]

I've run the RTCW (Return to Castle Wolfenstein) multiplayer demo test 1
server on a Linux box and when it was running, it was not too bad.. a bit
laggy in spots though.  But it does crash fairly often and leaves the
machine sitting there chewing large chunks of CPU cycles.  Test 2 is out now
though.. I haven't tried it out yet though myself, risk of upsetting some of
the kiddies on the Counter-Strike servers if it chucks a spack and eats huge
amounts of CPU :oP.

Myself and a friend run several Linux games servers in Perth
(www.3fragsleft.net), and its proven to be a very good platform to run it
all on :).  Apart from the fact that regular physical access to them isn't
an option for me, since I live in Broome and they sit in a particular ISPs
server room in Perth... I can do everything remotely...

All of the traffic from games servers running FPS style games is UDP,
otherwise the real-time nature would never work very well with people of
different network connectivity with TCP... it'd be a horrible mess, everyone
would be out of sync :).

I'd check the route to the games server box  from the dial-in users and the
route back from the games server box to the dial-in users, if its different,
then that might be one small problem, but I wouldn't think it'd cause 6
second lag-outs.

Also, there are rate settings, which the games server sets, usually a min
and a max, so the clients can only select a value within that range, if they
select a range outside of that, the server enforces the min or max dependent
on which one the client is under or over.  I'd check to make sure you
haven't got a minimum rate set to such a level that dial-in users only just
handle it most of the time, but during intense battle it increases the
bandwidth to such a level that even 56Kers will get lag spikes like that.
Oh and yes, it is based on the Quake 3 engine, so you configure it with
Quake 3 server commands. :)

I'd get a client to run a Pingplotter (www.pingplotter.com) whilst they are
playing, and then when they spike, it should reveal where the problem hop to
the games server is, or whether its an issue of too much bandwidth from the
games server to the dial-in clients.


/ Ben

----- Original Message -----
From: "Brian Tombleson" <brian at paradigmit.com.au>
To: <plug at plug.linux.org.au>
Sent: Saturday, November 10, 2001 8:26 PM
Subject: [plug] [OT] Wierd problem


> Just thought I'd ask to see if anyone can help with this one.
>
> A friend runs a regional ISP and they want to run a games server and have
a
> debian potato box running the newer wolfenstien game (Quake3 engine?).
>
> They have 2 Cisco access boxes (AS5200 and AS5300) and a Cicso 2611
handling
> their upstream and internal routing.
>
> According to a network dump, dial in users (the AS5?00's) are being
flooded
> with UDP packets during game.  No probelm at all for non-dial-in's (ie.
> coming across the net and through the 2611).  In certain parts of the game
> the ping times lag out to up to 6 seconds.
>
> We've looked at the linux box and there doesn't seem to be a problem.
> They've even loaded the Win2K version on a separate machine and it has the
> same problem.  No tweaking of game parameters has any affect at all.
>
> The 2611 *probably* isn't the cause because net-based players don't have
the
> problem.  Also, there no such problem with any other services - just the
> game.  Likely problem area is the 5?00 access boxes, but there's nothing
> obvious to try.
>
> Anyone got any advice, pointers or solutions for this?
>
> Any help appreciated.
>
> Regards,
> Brian.
>