Law Technology

Comcast?s Disappointing Defense

By Ed Felten

Last week, Comcast offered a defense in the FCC proceeding challenging the technical limitations it had placed on BitTorrent traffic in its network. (Back in October, I wrote twice about Comcast’s actions.)

The key battle line is whether Comcast is just managing its network reasonably in the face of routine network congestion, as it claims, or whether it is singling out certain kinds of traffic for unnecessary discrimination, as its critics claim. The FCC process has generated lots of verbiage, which I can’t hope to discuss, or even summarize, in this post.

I do want to call out one aspect of Comcast’s filing: the flimsiness of its technical argument.

Here’s one example (p. 14-15).

As Congresswoman Mary Bono Mack recently explained:

The service providers are watching more and more of their network monopolized by P2P bandwidth hogs who command a disproportionate amount of their network resources. . . . You might be asking yourself, why don?t the broadband service providers invest more into their networks and add more capacity? For the record, broadband service providers are investing in their networks, but simply adding more bandwidth does not solve [the P2P problem]. The reason for this is P2P applications are designed to consume as much bandwidth as is available, thus more capacity only results in more consumption.

(emphasis in original). The flaws in this argument start with the fact that the italicized segment is wrong. P2P protocols don’t aim to use more bandwidth rather than less. They’re not sparing with bandwidth, but they don’t use it for no reason, and there does come a point where they don’t want any more.

But even leaving aside the merits of the argument, what’s most remarkable here is that Comcast’s technical description of BitTorrent cites as evidence not a textbook, nor a standards document, nor a paper from the research literature, nor a paper by the designer of BitTorrent, nor a document from the BitTorrent company, nor the statement of any expert, but a speech by a member of Congress. Congressmembers know many things, but they’re not exactly the first group you would turn to for information about how network protocols work.

This is not the only odd source that Comcast cites. Later (p. 28) they claim that the forged TCP Reset packets that they send shouldn’t be called “forged”. For this proposition they cite some guy named George Ou who blogs at ZDNet. They give no reason why we should believe Mr. Ou on this point. My point isn’t to attack Mr. Ou, who for all I know might actually have some relevant expertise. My point is that if this is the most authoritative citation Comcast can find, then their argument doesn’t look very solid. (And, indeed, it seems pretty uncontroversial to call these particular packets “forged”, given that they mislead the recipient about (1) which IP address sent the packet, and (2) why the packet was sent.)

Comcast is a big company with plenty of resources. It’s a bit depressing that they would file arguments like this with the FCC, an agency smart enough to tell the difference. Is this really the standard of technical argumentation in FCC proceedings?

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Full post as published by Freedom to Tinker on February 18, 2008 (boomark / email).