Network bogs down??

[sgr]

Hi Pete,

If I fly my simulator for an extended period of time (over 1 hour) I notice the PM PFD display starts getting choppy, especially the speed and altitude tapes. They seem to look like they are running at 2 or 3 frames per second. This doesn't always happen, but maybe 50% of the time.

Now if I shutdown WideFS and PM PFD software and restart those programs, sometimes it goes away and runs smooth again. In a worst case, sometimes I have to power down all the PC's, and the Jetliner console, and restart the whole network.

Forgive me for being so vague, but it seems like maybe WideFS or the network is getting bogged down with data transfer. Or like the data is "stuck" (how's that for a technical term?) and not transfering between PC's. (It's a 100Mbps network with a single 5-port hub.)

Currently, I'm using IPX/SPX on a WinXP/Win98SE network. (yes, I tried it again.) But I've seen this with TCP/IP too.

So my question is, does this sound like anything you've seen before, and what is the fix? Or if you can't answer that just yet, what should I check to see if there is something causing network bottlenecks, slowdowns, or whatever.

Cheers,

Steve

[Pete Dowson]

If I fly my simulator for an extended period of time (over 1 hour) I notice the PM PFD display starts getting choppy, especially the speed and altitude tapes. They seem to look like they are running at 2 or 3 frames per second. This doesn't always happen, but maybe 50% of the time.

Sometimes folks get this sort of behaviour over in the PM support web/newsgroup. Did you check there? I'm not sure what the causes can be -- maybe something has a memory leak (do you notice an increase in disk activity?), or the network drivers for your network card, or maybe your hub or switch, is having problems. Or the video card/processor is simply not up to the job at the frame rate you are trying to drive it all at.

Are there any errors being reported at all in the WideServer or WideClient logs? That's really always the first place to look.

The other thing to check is the video drivers, especialy if it is only occurring on clients which are heavily display based -- the PM PFD.EXE program being a prime example. If it isn't happening with the CDU or MCP software, for instance, then this would tend to indicate something to do with the display system.

Forgive me for being so vague, but it seems like maybe WideFS or the network is getting bogged down with data transfer. Or like the data is "stuck" (how's that for a technical term?) and not transfering between PC's. (It's a 100Mbps network with a single 5-port hub.)

If there are no errors reported in the Logs, then the delays, if any, will be occurring in the lower levels of Windows network drivers -- maybe running out of buffers on a system where the processor is overloaded and not allowing the main application (PFD) to keep up with the traffic. WideClient won't be queuing anything -- if an update comes in before the previous one is requested, the previous one will simply be overwritten, so it never knowingly supplies anything out of date. What I think can happen, though, is that the PFD software and the video drivers it is using are taking so much time out of the processor that Wideclient isn't actually able to read the incoming frames fast enough.

There are two things to investigate, apart from checking the logscompare the FS frame rate with the frame rate achieved on the PFD software. Try limiting the FS frame rate to something which can be matched by the client PC. And see if the video card and driver is causing any problems, hold ups -- ask in the PM group about this sort of thing. There are some known problem cards I believe.

Another thing you could improve is to replace the 5-port hub by a switch. Switches used to be more expensive, but they are as cheap as hubs these days and much more efficient.

BTW have you tried the latest interim version of WideFS? We're up to version 6.615 now. The UDP protocol, now supported, can be significantly faster than either SPX or TCP, but it is less reliable. you have to try it and see -- check the logs afterwards.

Regards

Pete

[sgr]

BTW have you tried the latest interim version of WideFS? We're up to version 6.615 now. The UDP protocol, now supported, can be significantly faster than either SPX or TCP, but it is less reliable. you have to try it and see -- check the logs afterwards.

Hi Pete,

As I mentioned above, I have a mixed network. Can I use UDP with a WinXP server and Win98SE Clients?

I have some licenses for Win2k. Do you think I'd be better off running Win2K on the client machines, being that I have a WinXP server?

I'll try the updated WideFS.

Regards,

Steve

[Pete Dowson]

As I mentioned above, I have a mixed network. Can I use UDP with a WinXP server and Win98SE Clients?

Yes, it is part of the TCP/IP package, and is used by windows in any case I think.

I have some licenses for Win2k. Do you think I'd be better off running Win2K on the client machines, being that I have a WinXP server?

Sorry, I've no idea on that one -- I was a staunch Win98SE user, refusing to update any of my PCs until I had to on one of them because Matrox wouldn't do a Win98 driver for the Parhelia. I still resisted with the other PCs after, until the SP1 update arrived -- that made a helluva lot of difference, and I changed my mind!

Whether Win2K would have changed my mind I've no idea. I have one machine, running WinXP Pro normally, which has Win2K Pro on dual boot, but apart from testing things in it I haven't formed any opinion. Sorry.

Regards,

Pete