WAN users download files extremely slow…

[McDeth]

Help! I have been having issues lately with network throughput on any file that is accessed from an off-site location. Currently I have a Leopard server (running DNS, Firewall, NAT, VPN, iChat) that is providing authentication services to my users who are logging in from an off-site location. I also have a second server running Tiger server that is set up as an OD Master running AFP and providing authorization services to my users. This is where most of the files my users are accessing are located.

I have run speed test after speed test on our internet connection that consistently yields a rock steady 337KB/sec UL and 319KB/Sec DL (We have bonded T1’s @ ~3.072 Mbps) yet when users are trying to download or access files using AFP or FTP the server will sputter between 0-120KB/Sec and never achieve anywhere close to its maximum theoretical throughout. I have tried to confirm in as many ways as possible that this is a file service problem and not an internet connection issue. I regularly use Remote Desktop from my home to connect to the server that yields bursts and sustained speeds all the way up to 340KB/Sec. Again, bursts are not saying much, however when the server was displaying a screen saver in full color mode, the throughput was steady at ~3.072 Mbps. Furthering my suspicion that this is a service issue, I have set up a VPN that sends all traffic over the VPN and then logged in and visited Youtube and other download sites, all yielding the expected maximum 3.072 Mbps speeds when downloading files from the internet to my computer.

In order to try and narrow down the problem further, I have turned off the VPN service (thinking that perhaps the overhead for encryption for multiple users was causing the low throughput) and tried both secure and insecure AFP and FTP downloads from the server. Again, this yielded the same pathetic throughput.

Is there some issue with transferring files over the internet that I’m not aware of? I’m literally tearing my hair out trying to figure out where the problem is. Users are taking anywhere from 2-5 minutes to open small (<1MB) files and this is causing serious headaches. Alternatively, are there any other solutions that would enable users at multiple locations to access the same files at the same time?

Thanks for any help you guys can provide, I'll be more then happy to answer any questions you have.

[blake]

Internet speed tests and youtube use hosts that are closest to your local internet connection. If the endpoint of your wan connection is far away the latency will greatly effect the throughput.

If you ping the host on the far side of you wan connection what is the latency?

Check out IPnettunerx http://sustworks.com/site/prod_iptx_overview.html
I wouldn’t expect it to solve your problems but it is very helpful at measuring connections speeds. The documentation is also informative.

blake

[afterhours]

[QUOTE][u]Quote by: McDeth[/u][p]

I have run speed test after speed test on our internet connection that consistently yields a rock steady 337KB/sec UL and 319KB/Sec DL (We have bonded T1’s @ ~3.072 Mbps) yet when users are trying to download or access files using AFP or FTP the server will sputter between 0-120KB/Sec and never achieve anywhere close to its maximum theoretical throughout.
In order to try and narrow down the problem further, I have turned off the VPN service (thinking that perhaps the overhead for encryption for multiple users was causing the low throughput) and tried both secure and insecure AFP and FTP downloads from the server. Again, this yielded the same pathetic throughput.

Is there some issue with transferring files over the internet that I’m not aware of? [/p][/QUOTE]

What has your service provider said? I would like to think that you first checked with them to insure there is no filtering on their side that may affect your performance. Of course, the speedtest sites are a first step in testing that, but go beyond them and do your own tests FROM THEN SERVER for ftp’ing to a remote machine that is not on your network — preferably with better bandwidth than you buy so you can truly see any throttling effects.

If you are worried about the machine bogging down, I doubt that is the case. Do you have sufficient RAM installed for the machine? That’s one of the most common bottlenecks I see in servers. People go cheap and think a 512 Mb or 1Gb machine will be able to do all they need.

After you have spoken with your ISP (and gotten through the first level of tech ‘support’ from off-shore), and they claim to have nothing in your way, then you might simply try in the wee hours shutting off all services save for ftp. Test that. If you get close to your specs up and down, then reactivate services one by one, testing in between. You can also pull up something like the server monitor to watch network traffic, or a tool like menumeters instead.

We can speculate all day, but you need to isolate services to see if the behavior manifests irrespective of what is running, or is linked to any one service.

[Author]

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