Month: September 2008

A fellow named Paul Korzeniowski has written a very good, concise piece on the Comcast action at the FCC for Forbes, Feds And Internet Service Providers Don’t Mix. He manages to describe the controversy in clear and unemotional language, which contrasts sharply with the neutralists who constantly use emotionally-charged terms such as “blocking,” “Deep Packet Inspection,” “forgery,” and “monopoly” to describe their discomfort.

What Comcast actually did, and still does today, is simply limit the amount of free upstream bandwidth P2P servers can use to 50% of capacity. This isn’t “blocking” or “censorship,” it’s rational network management:

Cable giant Comcast is at the center of a very important controversy for small businesses. In the summer of 2007, it became clear that the carrier was putting restrictions on how much information selected customers could transmit. BitTorrent, a P2P application-sharing company, had been using lots of bandwidth, so the ISP throttled back some its transmissions.

“Throttled back some of its transmissions” is correct. Comcast doesn’t throttle back P2P downloads, which you can prove to yourself if you happen to have a Comcast account: download a large file using P2P and notice that it moves faster than it possibly can on any flavor of DSL. My recent tests with Linux have files downloading at 16 Mb/s, the advertised maximum for my account.

Korzeniowski then explains the facts of life:

The reality is that all ISPs are overbooked–they have sold more bandwidth than they can support.

This overbooking has been an issue since the old Public Switched Telephone Network (PSTN) days. In that situation, individuals would receive a busy signal when the network was overloaded. Because the Internet has an antithetical design, ISPs don’t have a busy signal option.

ISP’s actually do have a “busy signal option:” it’s the Reset packet that Comcast uses to limit active upstream sessions. But neutrality regulationists call it “forgery” and abhor it.

“Overbooking” bandwidth isn’t a bad thing, and in fact it’s central to the economics of packet-switching. The PSTN forces each caller into a bandwidth ghetto where he is allocated a small chunk of bandwidth, 4 KHz, regardless of how much he currently requires. If you’re on the phone and have to set it down to check on your chili, you have 4 KHz. If you’re blasting files over a modem connection, you have 4 KHz. It doesn’t matter how many other callers are on-line and what they’re doing: you each get 4 KHz. That’s the law.

But packet switching, of which the Internet is an example, allows your bandwidth allocation to float depending on what you need to do and what other people are doing. You share network facilities with your neighbors (and this is true whether you use DSL or cable, you just share at different points on these technologies), so you can get a larger chunk of bandwidth when they’re idle than when they’re banging the net hard.

Overbooking allows you to use very large amounts of bandwidth for short periods of time, which is ideal for web surfing: you click on a link, you get a ton of graphics sent to you computer. While you’re reading, your neighbors get to use the bandwidth that would be wasted if you had PSTN connections. It works for everybody, most of the time. It works so well, in fact, that ISPs haven’t bothered to meter actual bandwidth use: the resource is so abundant, and the demands so few (especially in the upstream direction, where your clicks move) that there’s never been a need to control or meter it.

Enter P2P, a method of moving large files across networks that relies on free upstream bandwidth. Now the abundant broadband upstream is constantly occupied, not by an interactive application that sends a click now and click 5 seconds from now and a click a minute from now, you’ve got applications running that constantly stream traffic up the wire, to the detriment of the others in the neighborhood. Something has to give.

One approach is to cap upstream traffic:

However, the “all you can eat” model may no longer be viable–a change the government seems to be ignoring. ISPs could use the open salad bar model when users were mainly transmitting small textual data. But with video becoming more common, users increasingly transmit very large high-definition files.

In response, Comcast plans to cap customer usage at 250 GB of data each month. That translates to about 50 million e-mails, 62,500 songs, 125 standard-definition movies, or 25,000 high-resolution digital photos. That amount would seem to meet the needs of most customers, including small and midsize businesses. The only folks affected would be companies such as BitTorrent, that have based their business on the “all you can eat” model, and hackers, who routinely spew out tons of unwanted solicitations and malware.

Capping has its critics, mostly the same people who object to traffic management as well:

For whatever reason, some believe ISPs should not be able to put any restrictions on the volume of information that any user transmits. That’s absurd. Per-bit and per-byte pricing models have long been used for data transmissions. In trying to build and sustain their businesses, carriers constantly balance their attractiveness and viability versus unlimited usage pricing models. By government decree, they no longer have that option. In effect, the FCC has decided to tell ISPs how to run their networks.

Capping frees up bandwidth for sharing by taking free bandwidth off the table for P2P. But it’s not a technically elegant approach. Humans respond to caps month-by-month, but networks experience congestion and overload millisecond-by-millisecond. So the sensible engineering approach is to manage traffic in pretty much the way that Comcast does it today: identify the bandwidth requirements of applications, and allocate bandwidth to those that need it the most, as we would with any scarce resource: grant transmission opportunities (that’s a technical term we use in network architecture) to highly interactive applications such as VoIP ahead of non-interactive applications such has HDTV file transfers. This is sound practice, but the FCC has now said it’s illegal. The FCC is anti-consumer.

Net neutrality supporters have pressured the FCC because they believe cable companies are unfairly monopolizing the Internet access marketplace. This conveniently ignores a couple of factors. First, there is no Internet access monopoly. A small or midsize business can get access from cable companies, telcos or wireless suppliers. True, there are not 50 choices, as you might have when buying a new pair of pants, but there is a reason why so few companies compete in the Internet access arena–it’s not a great business.

In fact, net neutrality advocates have turned a blind eye to the history of the dot-com bubble. Internet access start-ups burned through more cash with fewer positive results than any market sector in memory–and perhaps ever. Providing Internet access requires a lot of capital for the network and support infrastructure, and there’s not a lot of money to be made when customers pay about $20 a month for unlimited access.

The alternative to application-sensitive traffic management is a crude user-based system that treats all of each user’s traffic the same. This means, for example, that your VoIP streams get the same service from your ISP as your web clicks and your file transfers. This is insane.

Each Internet user should be able to multitask. We should be allowed to share files with P2P or any other non-standard protocol of our choice at the same time that we’re video-chatting or surfing the web. The heavy-handed FCC ruling that all packets must be treated the same undermines the economics of packet switching and delays the day when the Internet will make the PSTN and the cable TV systems obsolete.

Comcast was right to take the ruling to the courts to get it overturned. ISPs should be allowed to deploy a traffic system that combines elements of the protocol-aware system currently in use at Comcast with the new “protocol-agnostic” system that’s under test, such that each customer has a quota for each class of traffic. This is sound network engineering, but the current state of law makes it illegal.

This is not good.

Cross-posted to CircleID.

UPDATE: See Adam Thierer’s comments on this article at Tech Lib.

Technorati Tags: net neutrality, FCC, Comcast