Bandwidth Usage

BANDWIDTH and the COMMONS DILEMMA

How to fairly divide up a finite shared resource is such a classic problem that one would be tempted to believe it must have been solved by now. Unfortunately it seems that each time a shared resource is brought to the collective bargaining table it necessarily has a unique set of evaluation criteria and requires a novel solution to be derived. The latest and perhaps most visible of these problems is Internet bandwidth.

The Finite Nature of Bandwidth

While Willamette is equipped with 100 Megabit connections within all of the buildings and Gigabit connections between buildings on campus we have only four T1 circuits to serve as our Internet conduit for all users. (This is fairly typical for institutions our size.) This pipe is wide enough to transfer approximately six Megabits (770 Kilobytes) of data per second simultaneously inbound from the outside world and outbound from Willamette. At present this is the upper limit on our bandwidth resource that cannot be exceeded.

Potential Solutions

It's probably clear that we're dealing with a supply and demand issue. So it might seem that the best solution is merely to increase the bandwidth thereby increasing the amount of bandwidth available per user. This is where we find that Internet connectivity is different from other shared resources. Current high-bandwidth applications such as Kazaa and Morpheus are designed to consume whatever bandwidth is available. These aggressive peer-to-peer (P2P) type applications cannot be satiated. Therefore, even when the cost of increasing the available bandwidth is not prohibitive, the benefit can be negligible. That said, it never hurts to have a larger Internet conduit, and WITS is currently looking at ways of increasing the size of our connection without breaking the bank. However, since we cannot create a pipe large enough to satisfy the ever expanding needs of the community we necessarily must find a congenial method to divide it.

How to divide the resource

Some quick math will point out the obvious, namely that the 3000 plus members who must share this resource can not simply partition it off into small, equal parts. To do so would cause the Internet to become unusable to anyone without the patience of Penelope*. Fortunately not everyone is using the Internet at all times, at least, not yet. Since dividing bandwidth equally among users is not readily workable, Willamette is taking a multi-pronged approach to managing bandwidth. First, like almost every other school and business dealing with this issue, we have decided to partition the available bandwidth at the application level. Basically what this means is that your Internet performance, in addition to the number of concurrent Internet users, will also depend upon the type of application that you are using to access the Internet. Second, WITS has implemented a monitoring system that allows us to identify the users and applications that are consuming abnormally high amounts of Internet bandwidth. We are now able to find these "bandwidth hogs" and limit their access to the Internet if necessary.

Prioritizing Applications

Willamette has invested in a piece of network equipment to facilitate these endeavors. This traffic-shaping device is intelligent enough to sort Internet traffic based on the application and computer that generated the traffic and is able to partition the aggregate bandwidth into smaller sub-divisions of appropriate sizes. Traffic is then categorized as either low-priority, medium-priority or high-priority. P2P applications fall in the low-priority grouping; traffic generated by email, web browsers and the like fall in the medium-priority grouping; and time critical applications such as telnet and DNS end up in the high-priority grouping. Each category of traffic is guaranteed a minimum slice of bandwidth but is permitted to consume more bandwidth if it is available. This ensures that bandwidth-aggressive applications are not allowed to starve other applications of Internet access and frequently used applications like web and email are furnished with the resources necessary to function at an acceptable level. These recent implemented changes should result in better performance for all campus Internet users.

An Eye to the Future

Despite all claims to the contrary, it does not appear that the price of bandwidth will decrease dramatically anytime within the foreseeable future. Bandwidth consumption, meanwhile, has been rising consistently and significantly. As more and more services are pushed out onto the web and Internet access becomes even more ubiquitous, this trend will only continue. We recognize how important fast and reliable Internet access is to the Willamette community for research, business and student life needs. As part of a project with the libraries, WITS is working to establish a direct connection to the State of Oregon network that should offer an increased capacity to the Internet without a significant increase in costs. We continue to look for additional methods to keep the supply from being outstripped by rising demand.

*the wife of Odysseus who waited 20 years for her husband to return form the Trojan War