Housing provides high-speed Internet access as a service to all of our residents. Unfortunately, all of the bandwidth used by that service costs a lot of money, and our hardware can only support so much traffic from everyone at any given time. If every student were to use all of the bandwidth available to them 24 hours a day, our network would become unusable. Furthermore, the bandwidth used by RESnet is only a piece of the bandwidth used by the entire University. This includes all residence halls, university teaching departments, university operation departments, and users.
To keep RESnet bandwidth from overwhelming the network, Housing has instituted a set of rate limits that gradually limit the connections of the highest-traffic users on RESnet, and keep the network working well for everyone. This allows us to efficiently use our limited bandwidth resources, and continue providing high-speed access to everyone.
Rate limiting is the system that is used on RESnet to regulate high-traffic users. The basic idea behind rate limiting is that the more traffic you generate, the slower your connection will become. Rate limiting was implemented as a way of allowing residents to download large files while still being allowed to use the Internet. If you start a http download and then cancel it, your "traffic account" will be charged with the full file size. Except in severe cases, Housing does not disable connections for excessive traffic.
RESnet tracks traffic over a moving 24-hour period. What this means is that your limit class will be determined by the amount of traffic you have done in the past 24 hours. We currently have three limit classes that your connection can be placed in:
Aggregate means that your bandwidth is shared among all of the connections in your Restricted Class.
Rate limit classes affect your computer only - your roommate(s) have separate traffic records and will not be rate limited if you go over your limits. Rate limits affect all of your traffic, both on-campus and off-campus. You may be disconnected or contacted if we feel you are abusing the bandwidth policy by changing your MAC address or if we see continually heavy traffic (ie. in Class B for days at a time, etc...)
To view your traffic over the past 24 hours, as well as information on what limit class you are in, you can visit this page. There are a few things about this page that merit explanation. First, the page reports both your input and output. Input is data coming from your computer, and output is data coming into your computer. Our rate limit thresholds are based on the total of these two traffics, which can be seen at the bottom of the page. This page reports your traffic in bytes. The limits of 4000MB and 8000MB are equal to 4,000,000,000 and 8,000,000,000 bytes, respectively. Flows are another way of representing web traffic. You will not be rate limited based on flows. Please note: if you download a file via http and then cancel it mid download you will see the full file size reflected on the traffic pages.
As you can see in the following picture, the computer has been ratelimited for heavy traffic. Numbers in red are highlighted because the ratio of input to output matches the ratios that are often seen when filesharing programs are in use. The computer moved from unrestricted, to class A, then into class B when the heavy traffic continued.
Only traffic between your computer and a computer off campus will be represented on this page. This means that traffic that does not leave campus will not be counted against your totals for rate limits. There is no absolute way to tell what traffic is considered on or off campus, but a good guideline is that most web addresses that end in ".illinois.edu" are on campus.
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