What Comcast caps could mean for your surfing and streaming

Comcast has dropped the 250GB monthly limit on bandwidth that its subscribers may consume over cable broadband. For the moment, all limits are off, except with regard to what Comcast calls “the very small number of excessive users” who exceed some unknown higher threshold of bandwidth consumption. The firm plans to test the effect of higher included bandwidth limits (with a maximum of at least 300GB) in combination with overage fees of $10 per 50GB block—which works out to 20 cents per GB—beyond such caps. Wallow in pseudo-unlimited service for now.

The caps are likely to return, based on Comcast’s carefully worded statements about its near-term tests. But what does having no effective limit mean for Comcast subscribers right now? And how might you have to change your behavior when Comcast finishes its testing, installs its new limits, and starts charging fees for excess use?

It boils down to how you consume video through subscriptions, streams, downloads, and torrents; and to whether you routinely upload large amounts of data to sharing sites or Internet backup services.

Let’s break these variables out into three scenarios: downstream with cable television service, downstream without TV, and upstream.

Downstream with cable TV

Comcast brands its cable service with the ridiculous name Xfinity, and I’d better use it to avoid more confusion than the company has already introduced. If you have a television plus Internet bundle (with or without voice service), Comcast doesn’t count any Xfinity TV video that it transmits through its television set-top box against your data quotas, so that’s not an issue now nor will it be in the future. Comcast, like all cable firms, uses a broadcast model that devotes digital channels to making the programming on those channels continuously available. (On-demand service relies on reserved, empty channels in a given neighborhood that the service then assigns to particular subscribers when they request a movie or show.)

Comcast does split out video delivered by other means. With an Xfinity Streampix subscription— kill me, branding gods—Comcast subscribers can view certain TV series and movies via a Web browser or via an iOS app, and watch on-demand content available through a separate subscription. This Internet streaming video is accessible anywhere, but when you use it on your home network, it counts against your cap.

Comcast does exempt one kind of Xfinity programming from caps. When you use an Xfinity app on your Xbox 360. to watch on-demand programming, Comcast uses your Internet connection to stream the video, but doesn’t count it against your cap. It’s a curious choice, as using an Xbox 360 isn't fundamentally different from using a laptop. This circumstance may indicate that when caps return, Comcast will exclude all sorts of streaming video on your local network from totals.

(Comcast may have hell to pay for this, too, as an analysis from Internet backbone provider Level 3, which has jousted with Comcast over network policies in the past, appears to show that Xfinity Xbox streaming continues to work even when the Internet connection is otherwise flooded. Comcast agreed not to give its own data priority as part of its agreement to acquire NBC-Universal, and it may face legal action from the Department of Justice and Federal Communications Commission if this allegation proves true. Comcast categorically denies prioritizing its data.)

Without the cap in place, you might decide to use more streaming content and to unlock yourself from the set-top box and an attached television, but it would be difficult to watch so much that you'd exceed either the old 250GB cap or a new 300GB one, as your primary viewing will likely continue to be through the TV or from a DVR that records over-the-cable programming.

Advice: Quaff at Comcast’s streaming keg to your heart’s delight, but you’re unlikely to have trouble when caps return.

Downstream without cable

If you, like me, have little interest in 600 channels, but more interest in a limited selection of programs that you can cobble together from ad-supported sites like Hulu, subscription offerings like Netflix and HuluPlus, from streaming services like Amazon, and from Apple’s rent and purchase options for digital downloads, caps and the lack thereof will have a much greater impact on your Internet behavior. (I canceled cable—and later satellite—service some time ago in favor of Internet-only video access coupled with limited Redbox rentals and public library DVD borrowing.)

Have you held back on your Internet video consumption because you were afraid that you’d exceed your 250GB maximum and receive a call from Comcast warning you of a one-year ban from subscribing if you cross that limit again within 12 months?

It’s hard to know whether Comcast’s 250GB served as a deterrent for most people. I know I kept it in mind; and when the company added a bandwidth meter, I consulted it regularly to make sure that I wasn’t about to run afoul of it. But would the average person without a cable subscription cross that line? (Comcast said that until this last week the 250GB number was a guideline, not a hard limit, and that it focused on the heaviest users.)

A report a year ago said that an average household could consume 600GB of data by watching HD video at the same level of quality that set-top boxes deliver, and that extremely heavy users could exceed 1.4TB--though that doesn’t take into account high compression for Internet streaming services. Not all programming is available as a stream, either, despite HuluPlus’s extensive offerings. People may leave a TV on for 8 hours a day without actively watching it, and that is where the report’s figures come from. Internet consumption tends to be more intentional, and thus lower.

Apple says download sizes for its digital content vary from about 200MB for a standard-definition-quality TV show up to as much as 4.5GB for a 2-hour high-definition-quality movie. A 300GB allotment would permit you to download 66 HD movies of that length—or perhaps 60 with enough left to cover all of your email and nonstreaming Web browsing.

But streaming complicates the equation. Netflix, for instance, streams at rates ranging from several hundred kbps to nearly 5 mbps, depending on the source quality and your network connection's ability to deliver consistent performance. Still, 5 mbps isn’t the top streaming rate we’ll ever see. Though a 1080p HD signal at 30 frames per second can be encoded at modest quality at 5 mbps, a DVD uses roughly 10 mbps, and Blu-Ray as much as ten times that; broadcast digital TV can have throughput rates of between 8 and 20 mbps, depending on the station.

A 5-mbps data stream consumes 2.25GB per hour, which still allows a hefty 133 hours a month of viewing under a 300GB cap; that total works out to a little more than 4 hours per day over a 31-day month. Of course, 4 hours per day for a single person isn't the same as 4 hours per day for an entire household with a shared connection. In the latter case, a mere 65 minutes of streaming each day, at the highest quality settings, by each member of a four-person household would push the total past 300GB.

But that’s for now. Streaming quality will continued to improve, and every increase in throughput capacity increases the likelihood that you will consume more programming or higher-quality programming.

Gaming is generally not an issue. Huge downloads are rare, and even they run only into gigabytes, whereas hourly use is measured in tens of megabytes. A serious gamer would be hard-pressed to use more than several gigabytes a month in regular play.

Torrenting is a different matter: It's quite easy to rack up hundreds of gigabytes of downloads while retrieving material that you may never view.

Advice: Without a cap, you can go moderately crazy with downloads, as long as you don’t cross the line into what Comcast considers “excessive” use. But unless your household consumes hours per day of high-quality streaming video watched in separate sittings and coupled with frequent downloading, you may not have anything to worry about from a 300GB limit, at least for now.

Upstream for sharing and backups

Discussions of caps usually focus on the downstream direction, but Comcast and others measure use as the combined total of downloads and uploads. If you’re an amateur or professional photographer, a heavy torrents user, or a subscriber to an online backup service, you might run into this problem.

A few years ago, when testing Internet-hosted backup services for Macworld, I received a call from Comcast telling me that I’d consumed 600GB of service, and asking if I would please stop. I hadn’t been keeping track. But because I was “seeding” the backups of several home computers—creating the initial baseline set of data for each—I ran through an enormous amount of data. Seeding operations can be a killer, although many services let you send a hard drive with an initial locally made backup to avoid the time and potential disruption of that first big upload for each machine.

Backup software often lets you set a maximum throughput rate, but not a maximum level of bandwidth consumption over a period of time. Such software usually doesn’t provide easy reporting to help you track the full bandwidth consumed, either.

You could also run afoul of caps if you routinely shoot large amounts of video or use a high-megapixel camera, particularly if you store in RAW format and back up to a photo-sharing service or a hosted backup system. It’s easy to produce dozens to hundreds of gigabytes a month of new media in that way, and run up against caps when your photography upload usage is combined with your download usage.

Bandwidth consumption is also an issue in torrent uploads, as most torrenters participate in the shared economy by letting others gather bits and pieces of what they’ve downloaded. A large library of downloads comes with a large amount of uploading, too. (Depending on your torrent program, you can set throughput limits and ratio limits on what you upload to control that effect.)

Advice: Take advantage of the lack of caps to prime the pump on any Internet backups that you’ve planned but perhaps not followed through on. You’ll need to watch it, however, when caps return, as most backup software provides no indication about how much you’re transferring unless you look up reports.

Bust that cap

Even the 300GB cap Comcast sets is ridiculous, in any case. Pay a few dollars more each month for business-class service, and the caps are waived (although a multiyear contract is required, with a 75 percent cancellation fee). In competitive markets, such as where Cablevision and Verizon compete, no caps are in place. And independent ISPs like Sonic.net offer unmetered use and haven’t had a problem keeping up with demand.

Where the cap is set and how we receive information about approaching a cap remain the issues. Karl Bode, the editor of DSLReports, says that one problem is that “there’s nobody confirming these meters are accurate. ISPs want to bill like utilities, but don’t want to be regulated like them.” He believes this is “a disaster,” as Internet video distribution continues to evolve.

Comcast’s tests in particular regions should let people know exactly what they’re getting and not getting. For those of us outside the test markets, it’s time to figure out what kind of consumption we need—and whether 300GB will be enough when caps return.

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