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When connected to the internet at my University there are some websites and services that load incredibly slowly. Nothing actually appears to be outright blocked, but certain websites (mostly games, and sometime YouTube and social networks) load at incredibly slow speeds. While just about everything else seems to work just fine. Additionally Steam community features (chat, online games, and forums) all work fine, but updates/installations always time out. Torrents seem to be totally dysfunctional. Social networks seem to fluctuate from usable to unusable. The network connections likes to drop out completely during Skype calls (but comes right back after the call drops).

However most websites and services work perfectly fine, as if nothing is wrong.

What is weird is that there doesn't seem to be any actual blocking ("this page has be blocked by the access policy" kind of thing), and downloading massive files is not throttled (I downloaded over a GB of data at one point, and there was virtually no bandwidth fluctuation). And even if Youtube pages load slowly, the video will stream normally once it loads.

Furthermore there is no information from the university to indicate any kind of usage policy (beyond "don't do illegal stuff") and as a public university with resident students from around the world, blocking of gaming, social networks, and especially Skype seems strange.

What could be going on here? Are they just trying to be sneaky? Is this a (rather poor) attempt to keep usage down? Or is there perhaps something wrong with the network?

And beyond all that, what can I do about it? I (and all the other students) are technically paying for this service as part of tuition, so shouldn't I be able to use it? What can I do to get around this problem?

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What is weird is that there doesn't seem to be any actual blocking ("this page has be blocked by the access policy" kind of thing), and downloading massive files is not throttled (I downloaded over a GB of data at one point, and there was virtually no bandwidth fluctuation). And even if Youtube pages load slowly, the video will stream normally once it loads.

Looks like the uplink (either your University or its provider) is experiencing route capacity problems. I.e., for example, let's say that the total bandwidth available to the University is 100 Mbps; but due to the bottlenecks in between, the total bandwith between the University and YouTube, one route out of many, is 20 Mbps tops.

Now suppose that there are 40 students downloading videos from YouTube. Each of them will compete for approximately 500 Kbps. As a result, initial video load will be laggy, but once enough data has been buffered, the video is usable.

At the same time, you download the latest Linux tarball from kernel.org. 20 Mbps are busy with YouTube, and 500 Kbps of those are streaming to you. But some ten Mbps are still available to you and a full 80 Mbps are still available on the University pipe: of these, 15 Mbps make it through to kernel.org. And you have a 500 Kbps YouTube and, on the same machine, a 10 Mbps download.

What could be going on here? Are they just trying to be sneaky? Is this a (rather poor) attempt to keep usage down? Or is there perhaps something wrong with the network?

I'd go with the last option. You will probably notice that popular sites are hogged, but sites on networks where nobody wants to go are still fast.

Update

OK, so that's not it. A cause that now seems likelier is that there's something between you and the quirky sites, something that looks like a firewall run amok, that delays processing of some kinds of contents, based on not-too-deterministic circumstances (maybe it's undersized and it sometimes get overloaded). The fact that this is affecting only some pages on a single site seems to indicate this.

Now, I could set up a pair of pages somewhere that print page generation time. If you can determine some kind of content that triggers the delay with reasonable reliability, I could put that content in one page, a dummy content of the same size on another. Then you would see that both practically-static pages, on the same site, display identical generation timestamps but arrive with wildly varying delay; that would clinch it and it's something you could bring to your U's network engineering support.

Or with some luck you could do this yourself, if you found some site that displays page timing statistics (I seem to remember seeing Joomla doing this?), and is affected by the variable-delay syndrome.

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  • Accept it's not just popular sites. There is a online game I often play, and the online player count averages 50 (total players). And I know they are not all from my school. I would estimate that ~1 person (me) from my school is on that game. So if the problem is as you describe, that site should not be effected. – zeel Oct 21 '13 at 22:26
  • You're correct. Your symptoms look now more like SPI/DPI gone awry (e.g. overloaded SPI firewall). You might want to involve the University's network engineers/support in the matter. Updating answer... – LSerni Oct 22 '13 at 7:19
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First, regarding the fact that you're paying for it: you're paying for it under their terms and conditions, which is a distinction that not many people realize. (I am not condoning meddling by IT; my university has one of the strictest firewalls I've ever seen, and I hate it. But I pay them to use their network.)

Investigating

Now, regarding exploring your network connection, there are several things you can do. If torrents don't work, it's entirely possible that they're blocking inbound UDP, throttling torrent traffic by port, or performing deep packet inspection (although the last is expensive). This leads me to the first thing you can do: portscan yourself. You'll need a public IP address to do this effectively; otherwise, you're basically just portscanning the router that is providing NAT! There are numerous online services that will do this for you, or you can use an offsite box that you have shell access to. If all UDP ports are listed as "filtered" or "blocked", there's a good chance that your university is blocking inbound UDP. (You can't be 100% sure, though, because of the way UDP is designed.)

If you have access to a VPN proxy server, you can investigate slow loading speeds for websites just by bouncing through the VPN. (If you're savvy enough, Amazon's EC2 provides a free tier that you could temporarily use as a VPN server to test with.) If sites load normally over the VPN, it's a sign that your school might be throttling traffic. I'll agree with you--that's a pretty underhanded thing to do.

A more likely story is that the infrastructure is insufficient or failing. Try pinging a website like www.google.com. (On Windows, boost the ping count to something high like 50 or 60.) If you get a lot of dropped packets (on a wired connection--wifi doesn't count), that's a sign that the infrastructure is poor; some of your traffic is "lost in transit." This is most likely not by design; nobody (not even anal sysadmins) want unreliable connections. Also, if latency is high, in the hundreds of milliseconds, that would explain why websites load slowly but large downloads work fine: websites are small, so you get a small amount of data with a lot of lag, but downloads are large, so you don't notice the lag because more packets are in transit at once.

In your situation, you don't have a whole lot to lose by just going to the IT department and complaining (bring your laptop and demonstrate, especially if they're dropping packets). At worst, nothing will happen, at best, they'll fix it (*rolls eyes*), but as a compromise, you might learn why the network behaves that way.

Good luck!

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  • I have run pings, and the packet loss is very low (and I have no wired access, so I can attribute that what there is to the Wi-Fi). As for the latency theory, I think not. I have tested page loads on effected web sites and the upstream time is nominal, but the downstream time is extremely long - but only for certain pages. All other pages are normal. And to be sure, I tested the same site immediately through my phone's tethered connection - zippy as can be. – zeel Oct 21 '13 at 19:53
  • What's the latency on the pings? And when you say "upstream time" and "downstream time," do you mean the bandwidth or the latency? – thirtythreeforty Oct 21 '13 at 20:20
  • I mean the time it takes to request a page is normal, the time it takes to download it is extremely high. – zeel Oct 21 '13 at 22:20

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