Joho the Blog
An Entry from the Archives

As a former systems engineer, I hope I "get" the edge-center distinction, but I'm not sure I see the locus-of-control issue raised here as a bona fide example of it. Aren't obnoxious schemes such as the V-chip and hardware profiling in Windows XP edge-resident? What we hate about these schemes is the loss of self-determination, but that seems to come from an open-closed distinction rather than a topological one. Authoritarian controls can be implemented either centrally or at the edge.

What's interesting is that, from an engineering perspective, once you decide to get Draconian on users' asses, there are efficencies - what Saltzer et al. call in their seminal End-to-End paper performance enhancements - to be gained by embedding functionality in the network.

This in turn suggests that the World of Ends argument is not so much a capital-t Truth as an optimization under the assumption that Information Wants to be Free. Where it doesn't - for instance, in Microsoft's (closed) vs. Sony's (open) approach to building online gaming services - end nodes are mostly the places people drop in their quarters.

Edge-based authoritarian proposals aren't authoritarian unless there's compulsion coming from an authority. E.g., there's nothing authoritarian about my installing a "family-friendly" filter on my home computer. It becomes authoritarian when it's not an impulse from the edge but a compulsion from the center: "All TV's shall have a V chip and all programming shall speak to it." Likewise, XP's hw inspector comes in a system that through various practices (some of which were legal) occupies the center. So, I think there is a topological component here because closed apps/systems that occur only on and from the edge can be accepted or rejected, while ones that embed themselves in the center are therefore much harder to reject.

It is clear that I'm using "center" here differently than the E2E guys did and differently than you're using it, Gordon, since I count market dominance as an occupying of the center even though XP is running on edge machines. So we may be agreeing.

The WoE argument, like the E2E argument that it attempts to recapitulate, doesn't say that all center services are bad, only that there has to be a good reason for putting them in the center, for there is a price to centralizing. WoE attempts to put this in terms of agreements rather than network performance because Doc and I just don't know all that performancey stuff.

Ah, ok, cool, once you extend the definition of network design to include politics, then V-chips and XP become edge implementations of centralizing policy (police-y?), and we come closer to agreeing.

One question that remains is whether you believe a closed approach is ever justified (and therefore that centralized or network-embedded optimizations are sometimes desirable, say for business reasons), or if WoE implies that openness and end-orientation are context-free design virtues.

Outside cyberspace, for example, we don't seem to balk at networks of vending machines that are "closed" in the sense that I can't get Pepsi from a Coke machine. Being closed networks, most vending intelligence resides not at the ends (as E2E prescribes) but in the supply chain - in central or embedded effects like manufacturing and distribution. At the risk of hurting myself, how do you think we should extend the analogy to embrace MMOGs? Should they be extensible opt-in networks with minimal infrastructure and maximum provider diversity (which is how I interpret Sony's strategy)? Or are they service vending machines (pace Microsoft)?

The thorniness of this question was driven home to me recently by a NewsFactor.com article [1] quoting Yankee Group: "[Game developers and publishers] don't have the infrastructure and don't want to spend the money for it. Microsoft is taking all the risks on themselves. It's a much more risk-free invitation than to create a [online] game for Sony right now.... "

1. http://www.newsfactor.com/perl/story/20937.html

No no, E2E isn't an absolute! It is merely a *preference* that can be undone by all sorts of considerations.

I'm not sure I'm getting your point about massively multiplayer online games. The NewsFactor article you point to (for which: thanks) seems to me to say that the Xbox is beating PS2 in MMOGs not because of a difference in approach but in execution: MSFT is doing a better job with the infrastructure and with the clients as well. I'm missing your point about the extensible opt-in networks.

In any case, I'm happy to let the market decide, so long as it's a genuinely competitive market. I mean, Doom/Quake did great by giving away very playable demos and by enabling people to do mods. While I might suggest that as a business strategy to another game company, I wouldn't suggest that there's some type of moral imperative behind it.

Whats' the betting that within a weeek of installing such a device the child will be metering the parent's TV consumption instead?

My boys always get the root password via ingenious social engineering attacks.