Nobody's going to tear down the Internet and rebuild it from scratch, but academics at Stanford University are imagining what the new blueprint would look like if they did and they hope their work will lead to an Internet that works better in 20 years than it does today. So far the program, called Clean Slate Design for the Internet, has narrowed down what it considers four key problems that need to be addressed: establishing a sustainable economic model for the providers that own the Internet infrastructure; establishing a trust mechanism so people can know with certainty where traffic comes from; upgrading mobility from an annoying special case that isn't handled well to a mainstream access mode; and improving performance.

Clean Slate participants, who include representatives from networking vendors and service providers, met last week to discuss their progress. Tim Greene talked to the leader of the effort, Associate Professor Nick McKeown, about how the project is going.

What's the point of a new blueprint for the Internet in the first place?

You might think of it as a purely academic exercise: If we got the chance to start over, what would we do? The outcome of that could be a really well articulated blueprint that says this is how it should be. We could say, 'This is what we should do and how do we get there?'

The other way is to say, 'Where would we like it to be in 15 or 20 years?' This is the approach we're taking and as part of that thinking about how might you get there.

So where do you want to be?

Anything we say now is a little bit half baked or a tenth baked. There is a collective belief that it needs to be done and only a partial answer as to how.

First the infrastructure of the network needs to be economically sustainable. The problem is the network operators aren't making any money from public Internet service. There are some good reasons for that. They were starting a business for which the marginal cost of providing service for an extra customer is zero. That makes it a natural monopoly because in a competitive market if the marginal cost of providing further services is zero then the competition is going to drive the price down to zero and everyone is going to go out of business unless they've already paid for their infrastructure. Who's paid for their infrastructure is the biggest guy and he's going to wind up with the monopoly.

It may be that the right outcome is to say we just accept that this is going to be a monopoly and see how within that environment do we make it work well.

What about trust?

We want a network that is trustworthy and within that I would include security. Denial of service, viruses, worms and to some extent spam are consequences of the Internet architecture. They're not inherent in any communication mechanism. They're hard to solve because it's very hard to determine the origin of packets. How do you tie a person to the data that is sent?

We are thinking of removing the Ethernet access switches and replacing them with switches that contain a flow table and basically nothing else. If a packet arrives and it's not in the flow table it will send it off to a centralized controller. The routing decision is made by the centralized controller, the accepting of the flow is made by the controller's policy decision. This gives administrators centralized control over what flows are allowed on the network, which would reduce the ability of viruses to spread, for example.