Examples of Discriminatory Protocols

Consider a few examples of ways that a protocol might discriminate. Many forwarding protocols tend to favor applications that generate large packets over applications that generate small ones. Other forwarding protocols favor applications that generate traffic in steady streams over applications that generate traffic in bursts even if the total amount of traffic is the same. Almost every protocol provides different service based on roundtrip times (and hence distance). There are protocols that mitigate or eliminate some of these effects. It will be interesting to see whether the FCC can craft principles nuanced enough to strike the right balance.

One might regard these forms of discrmination as weak or indirect. Even more interesting are routing policies that explicitly discriminate on the basis of source. To quote the four examples used in a leading textbook on computer networking:

· Never put Iraq on a route starting at the Pentagon.
· Do not transit the United States to get from British Columbia to Ontario.
· Only transit Albania if there is no alternative to the destination.
· Traffic starting or ending at IBM should not transit Microsoft.

Whenever these policies are invoked, they will necessarily force certain traffic to pass through more hops (or in the case of BGP more autonomous systems) or otherwise deviate from whatever the router’s protocol is trying to optimize. From one perspective, this would constitute degradation on the basis of source or destination. And this isn’t even getting into the Type of Service flag already embedded in the IP layer or the efforts like IntServ, DiffServ, and MPLS that propose alternative means for implementing quality of service.

Bear in mind that many routing policies attempt to improve network performance by prioritizing on the basis of application. Some users unable to get this functionality out of the network are purchasing overlay networks that perform the same functions in ways that represent even larger deviations from the seamless web of the Internet that middleware is making ever less seamless all the time.

The Chairman’s speech did embrace the case-by-case approach that Jim, Phil Weiser, I, and others have been advocating (although we differ in some important ways on the details). To work, the FCC should give industry actors given enough advance guidance so that innovation and investment is not chilled while we are waiting until there are enough cases to provide sufficient guidance about what is permissible and impermissible. Otherwise the case-by-case approach will be destined to become another iteration of what Jeremy Bentham called “dog law” (that is, you house train your dog by waiting until it pees on the carpet and then wallop it while it stares at you in confusion until the doggy “accidents” happen enough times for it to figure out what is going on).