Install a traffic shaper and you're bound to feel some political heat--and we're not talking about how many people are streaming Limbaugh on your LAN. We're referring to the massive debate and flame mail you will get for limiting protocols.
You probably know which protocols are overwhelming your network. Are people clogging up your bandwidth with e-mail or P2P traffic? In the enterprise, expect each administrator--the person in charge of VoIP, the Web dudes, the e-mail admin--to want highest priority. Before you jump into this quagmire, get a fair, well-thought-out policy down on paper, and get CxO-level buy-in for that policy.
If you're in an educational setting, the problem protocol is almost guaranteed to be P2P. But do you block P2P protocols outright? This is where politics--more specifically, avoiding a student uprising--comes into play. Blocking P2P completely will likely get you hung in effigy. A larger concern, however, is the legal aspects of P2P. Most P2P material traversing your network--including Kazaa, Gnutella and the infamous Napster--is copyrighted. Such transfers fall outside fair-use rules and are in violation of federal copyright law.
Does this mean allowing P2P traffic on your network or trying to rate-limit it opens you up to legal liabilities? So far, that's not likely, but check with your institution's lawyers. The Digital Millennium Copyright Act states that a service provider is not liable as long as the provider doesn't have actual knowledge that a material or activity is infringing on copyrights. And, while much P2P traffic is infringing, not all of it is.
At some point, however, content creators may discover an infringing user on your network and issue a notification. If this happens you need to disable or remove the content; failure to act can result in liability. However, this same thing will happen if a user hosts infringing material on an internal Web server as opposed to P2P. Based on precedents at print time, there is no indication that allowing or rate-controlling any particular protocol will open you up to liabilities. Because most content creators are interested in suing the people distributing infringing content--as opposed to users downloading files--several institutions have decided to severely limit or completely block outgoing P2P traffic. Others limit all P2P to just a few kilobits per seconds, thus allowing the traffic but at a rate so slow that nobody wants to use it.