Thread: network issues
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Old 11-08-2005, 04:56 PM
David J. Wilson's Avatar
David J. Wilson David J. Wilson is offline
Join Date: Jun 2005
Location: Parsippany NJ
Posts: 14

Originally Posted by Justin M. Giza
It was explained to me today that the academic buildings are given high priority (not on wireless), and upon testing this with good ol' Warcraft 3 (I figured it'd be a good test-program) in my spare time, I found it to run flawlessly at 7pm tonight (usually a busy time, I've noted).

Out of curiousity, and please correct me if I'm wrong (I have no real working knowledge of network traffic), is there any way to re-route this open access to the rest of campus? Just how much of this space is left open? I'm not sure exactly how your software divvies up the connection, but I can most certainly promise you that most of the folks in their offices seldom use anything all that network-intensive, at least from what I've seen.

So... to summarize: how much is left open in academic buildings, how much is actually utilized on a day to day basis, and is there any way to reroute this bandwidth?

Whoever explained this to you has no actual knoweldge of how our network and internet connection is configured. Allow me to provide you with some facts-

The internet connection is not split up between FS, Students, Wireless and so forth. We only identify and categorize them separately on our packet shaping device for management purposes, like getting a more detailed depiction of how the bandwidth is being utilized by users on campus. They all share the same QoS (quality of service) policy. You can see this for yourself if you follow the link to the screenshot below. Each connection group shares the same "Normal" policy. Note that the first two groups are only for testing purposes and are disabled 99% of the time- You can see that they are greyed out.

If Warcraft 3 worked fine for you in an academic building it was just a coincidence, because it should work exactly the same way in your room. There is no difference as far as how our packet shaper is configured.

We have made a lot of positive adjustments to it in the past week. Unfortunately during this same time, the device has started to crash multiple times a day, taking the internet down with it. We've been working with the support staff for the product and they have identified the cause as being a bug in the version we were running. They recently put out a newer version which is supposed to correct the particular issue, and we've already gone ahead and upgraded it this afternoon. Assuming they correctly identified the problem, we should be much better off now. If not, we'll continue to work with them until it's resolved.

The above is why your AIM has been disconnecting, why streaming radio would stop, and why you wouldn't be able to re-establish the connection for about a minute. Keep in mind though- The internet is not perfect. Sites go down, as do any of the ten to twenty routers you go through to get to one. It varies. Same goes for speed and latency. It can be our connection, I'm not saying it never is, but it's certainly not always.

Only one thing is limited-and it goes for the entire campus. We heavily limit P2P for one reason: No matter what we set it to, if it's 1Mb or 10Mb, it's pretty much guaranteed that all of that bandwidth will be consumed at all times. I have seen it for myself. Personally I feel it's like throwing away bandwidth that legitimate applications could be using. Granted there are legal and legitimate uses for P2P like with BitTorrent- But honestly, that is rarely the case. Regardless, we recognize that and have not completely shut off P2P.

For games, I know many of you have questions regarding this. For the games that our packet shaper recognizes (and part of the problem is that it doesn't recognize all of the ones that are played here-we may be able to work on this), we actually have a QoS policy to *guarantee* bandwidth per connection so that games are able to work better. We do the same thing with streaming media, because these are both persistent connections that won't work if the available bandwidth falls below a certain level. There is a cap on how much of this we can provide but that is only because we have to still allow other applications to work. The idea that we don't care about this stuff working, that we would try to limit use, that's just false. But there is naturally a limit to what we can provide, and we have to think of all the users who are online and what they are using the internet for.

Here's a link to one more screenshot. It was taken this afternoon, a graph of the current usage at the time. Bandwidth is distributed rather evenly among WLAN (wireless), SRV (our servers, but mostly the proxy server), ST PB (students) and FS (faculty/staff). Look at the bottom left for a breakdown of the most active protocols.
(The times are GMT)

At night it's an entirely different picture- Primarily student, then some wireless and servers, nothing in fac/staff. If nothing else was happening, the student side of the network could use 100% of the connection- And that is always the case, it's not a policy that goes into effect at a certain time and goes back later. There's no bandwidth reserved for a particular group or location. The only thing we reserve or guarantee bandwidth for are specific applications that need it (academic software, streaming media, games, etc.) And in those cases, the bandwidth only gets reserved as it's needed and used.

Like it's been said earlier, we do listen and we're doing the best we can to make the most out of our connection. I actually care about improving service and adjusting it to match the needs and of the community, and not just because it's my job to. Besides the brief outages this week which I hope we're through with, I actually think the latest adjustments have helped quite a bit, I've been able to get very fast transfers, web pages load up fast, streaming audio works (and again, some servers are just overloaded or too far away- my cable connection at home may be super fast but there are still plenty of streaming audio or video servers that cut out or outright don't work), and so on,. No it's not blazing super fast, but it's been really good considering how many other users are sharing the same connection.

I hope this answers some of your questions.


Last edited by David J. Wilson : 11-08-2005 at 05:06 PM.
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