Comcast’s 250 GB Cap and Some Inside Info on Network Management

Karl Bode at Broadband Reports broke the news this morning (now confirmed) that Comcast will institute a 250GB bandwidth cap starting on October 1st. Nobody likes a cap, but as far as they go, this one’s pretty generous. It’s also far from unprecedented. Time Warner Cable made a lot of (negative) news when it started trialing a 40GB cap earlier in the year. But some of the smaller cable operators have been capping or metering for years. CableOne, for example, limits downloads and uploads during the time period between Noon and Midnight. The base plan allows for 1.3GB downstream and 131MB upstream in a day, and if you exceed those caps, the operator will slow down your connection. Meanwhile Sunflower Broadband appears to offer only 1GB downstream per month in its base plan. On the other hand, you can add extra gigabytes for only a dollar each in advance or the operator will charge you two dollars after the fact.

The one bit of good news around the fact that the big cablecos are getting into the capping game is that at least now we’re having a discussion about what’s reasonable. For example, should network management include caps, or slowed access for heavy users during peak times, or both? (I know “neither” is the ideal answer, but it’s also impractical.)

And, how much bandwidth is really enough? Keep in mind that the operators themselves don’t want to limit bandwidth too much because of the revenue potential from new services. As more IP devices hit the market, there are more opportunities for cable companies to sell broadband apps and even hardware/software bundles. Limitations on consumers are also limitations on cable revenue.

Which brings us around to the most important point. Capping and metering do not increase bandwidth capacity. Even as they set management policies for Internet use, operators still have to work continually to increase overall bandwidth availability. Good for the consumer, good for the cable company. Hell, it’s good for the country too.

Now one little extra tidbit. It turns out, unsurprisingly, that bandwidth management is more important in some places than in others. Apparently network management technology gets turned off by accident on occasion, and in one instance I heard about just this week, a not-to-be-named operator had network management accidentally turned off for two weeks before anybody noticed! I’m thinking the operator is probably not based in a college town.

38 thoughts on “Comcast’s 250 GB Cap and Some Inside Info on Network Management”

  1. I’m on Comcast… I wonder if they are going to provide a tool for keeping track of your bandwidth. Even something on their website.
    I keep track of my bandwidth using PRTG, but I know I miss some since I have to keep my computer on to monitor it, and my computer is not always on.
    So far in August it is reporting that I have used about 75GB total. Keep in mind I have been watching about 1.25 VUDU movies a week and there are three adult internet users in the house.

  2. I wonder if the various service tiers will get same cap too. It would make sense that if I pay for better upload/download speeds, I should get a better cap too.

  3. xdreamwalker hits the nail on the head. I’m not categorically against caps, but I would like to know when I’m getting close to the cap, and what is the penalty for exceeding the cap. I might be willing to pay extra for a larger cap, or be willing to be throttled at times if I exceed the cap. But unless I can assess my status, I am going to be nervous. Furthermore, many broadband users (and all power users) attach multiple devices to the broadband pipe: several computers (his, hers, work, kids), perhaps a TiVo, Vudu, AppleTV or whatever. Just being able to measure the bandwidth used by one computer gives me no information about the other computers or devices.

  4. Greg, I would be more then nervous about not being able to know how much I have used, I would be angry. It would be like Sprint telling me that I have 700 minutes a month, but not letting me check to see how many I have used. Hopefully Comcast get’s this right.
    I think I am able to catch most of the traffic from my house. PRTG from hooks up to my router using SNMP, but the computer running PRTG has to be on in order to capture the data.

  5. I can’t imagine Comcast won’t provide a meter. Time Warner Cable does. Sunflower Broadband does. And it will have to measure all IP devices… like Comcast’s new IP phones due out before the end of the year.

  6. Although come to think of it, the bandwidth from Comcast IP phones may be measured separately because it’s a hosted, quality-assured service rather than over-the-top. Not sure.

  7. Personally as a Comcast customer I’m probably fine with this cap as long as Comcast provides a way to track your usage.

    HOWEVER, it turns out they AREN’T GOING TO PROVIDE THIS.

    Just check out the faq page at:


    “There are many online tools customers can download and use to measure their consumption. Customers can find such tools by simply doing a Web search – for example, a search for “bandwidth meter” will provide some options. Customers using multiple PCs should just be aware that they will need to measure and combine their total monthly usage in order to identify the data usage for their entire account.”

    Meaning, that if you use a Tivo and an Apple TV and a laptop and a desktop, and so forth… you’re just SOL.

    Anybody know of software that can track the usage at the broadband router? Or an 802.11g/n router that comes with good software for such purposes? Or a way to pull that info out of your cable modem? Or should we all just call Comcast daily and ask where we stand as of today?

  8. Seriously, does anybody know how to do this yourself?

    I have a lot of computers, Tivos, Apple TV, etc that connect to the internet, and tracking usage isn’t even possible on some of these things that I’m aware of.

    I have a recent Linksys WRT300N (v1.1) Router, that if it supported even basic transmit/receive statistics with a CLEAR button or even a reboot at the start of each month would give me a way to track this. But at least scanning through the options in the html interface, I don’t see anything. Odd.

    If there were an in-line Ethernet switch with battery backup and an LCD display to track GB used I’d buy it…

  9. Do any of the Linksys WRT54G firmware replacements (e.g. tomato) give you a bandwidth counter (in addition to the QOS and other stats that I’m pretty sure they do provide)? If so, that might be the way to go…

  10. Steve, I have a WRT54G with Talisman firmware from
    I use PRTG Network Monitor from

    I have added SNMP to the router and PRTG looks there for traffic and tracks it.

  11. Tomato does provide a bandwidth counter. According to my router, I used 246GB so far in august and of course the month is nearly over. I’m a pretty heavy user, though.

    My concern isn’t whether 250GB is sufficient now; it probably is for nearly everybody. And not “nearly everybody” like the top 90%; I’m talking the top 99.99%. Heck, it’s probably sufficient for _me_!

    The real question is how they’ll handle this in the future as broadband applications like IPTV become more ubiquitous. Will they use the cap as an excuse to hold off on building their network?

    I don’t have comcast, but I do have time warner. They’re not quiiiiiite as evil but really it’s like comparing Franco to Stalin.

  12. To everyone annoyed at the caps, I might mention a couple of services called ‘DSL’ and ‘Satellite TV’.

    Of course, that’d be no fun, then you couldn’t whine about ‘The Man’ getting you down…..

  13. Wow. I see everyone here is making apologies for evil Comast. Are you all on some kind of paid “affiliate” program? You sign-up as an official Comcastic Apologist® and they raise your cap a few megabytes?

    Think back to the Boston Tea Party, did those guys go “…Well I guess it’s cool for England to abuse us in this way….Hey let’s go home and tell the people we know to chill out and just accept this kinda treatment. Don’t throw that tea into the harbor.”

  14. To answer one of the questions above, yes the tomoto and DD-RT software for linky routers DO provide bandwidth meters, but the problem is, if the router reboots at any point (which it often does at least once a month) then the stats are gone.

  15. So….i suppose the time has come for the big switch to FiOS…first I’ll call comcast and review why im taking my outrageous 180/mo bill to another provider..then ill treat myself to a higher-tier plan with FiOS

    has anyone heard if fios will soon have a similar cap?

  16. Frank, I have not paid for PRTG. They offer a free version that only allows 10 sensors, which is 9 more then my house needs.

  17. Frank, DSL speeds are insufficient for my needs and of course they’re not immune to caps. Though – as soon as Verizon wires my neighborhood for FiOS though, I’m jumping ship.

  18. Well of course, I’d switch to FIOS too if it were available. Also, I would commute to work in a hovercraft. And I’d like to start fires with my mind. And teleport.

    Realistically, given America’s last-generation infrastructure it’s going to take a _real_ investment to get us to parity with western europe. Verizon is making an admirable attempt and I applaud them for it, but it’s just not enough.

  19. First of all, if people don’t stand up and complain about caps, what is to stop ISPs from slowly reducing them until we are down to TW’s 40GB test-cap? Opponents of caps need to take it up with FCC and could probably use the old argument about restricting Internet & technology development, etc, etc.

    Secondly, Comcast isn’t even offering a meter or a defined standard of what’s going to count (all traffic or minus overhead or something else). I like this comment from Om’s post:

    “squidhammer said:

    Too right. I’ve worked on this very issue for a cable ISP (not Comcast). Everyone recognized, or came to recognize, that charges and limits would not fly without a bulletproof ISP provided meter. Anyone who wants to proceed without one is inviting lawsuits and government intervention. The only thing worse than the PR hit for instituting such a program? Having to suspend it because you can’t measure what you are charging for.”

  20. Dave (or anyone else, I suppose), out of curiosity, just what do you need the extraordinary bandwidth for?

    I personally use the slowest DSL package AT&T offers, and have no issues streaming video or audio, and don’t care if a 250MB patch downloads in 60 seconds or 10 minutes.

    Not posting this to start a flame war, I tend to want the fastest/bestest out there. But for fun, I switched to the slowest speed offered, and rarely feel like I’m missing out. And at $15 a month, the price is right.

  21. Frank, I download/stream (legit) video both in and out of my house – think Vudu, Xbox, Slingbox, etc. A typical HD movie download may run 5GB. I also use services like Mozy and now SugarSync for personal archiving – uploads and downloads.

    In terms of sheer numbers, I’m probably under 250MB. But our Internet usage will no doubt increase and I wonder if Comcast will scale the number. I also wonder why there isn’t a higher tier plan, that their default reaction is they disconnect you after two overages.

    Internet could now be considered a public utility. And like Ivan, I wonder if this will end up in court. Especially if Comcast’s own VoIP offering and video sites are not calculated in the monthly quota. Which of course would be non-net-neutral and anti-competitive.

  22. “…I also wonder why there isn’t a higher tier plan, that their default reaction is they disconnect you after two overages.”

    Ummmm…cronyism, collusion with the RIAA ( MPAA and )?

    “We are pleased that Chairman Martin, Commissioner Tate and others recognize that protecting valuable copyrighted works is central to any discussion about network congestion. We look forward to working together with the FCC and private parties such as Comcast and BitTorrent to ensure that the theft of music and movies is addressed as part of conversations to make networks more efficient.”
    – March 27, 2008

  23. Can you get 2 Comcast accounts and use each for 250GB a month? I’m not a Comcast customer (Time Warner) but I see caps coming all around, it’s just a matter of time.

    My main concern is actually ‘the cloud’ – I was shopping Amazon S3 as a secondary backup solution, but if I’m backing up my modest 200GB machine 4 times a month, that’d get me suspended in most parts of the country starting 10/1. Something to think about fer sure as I contemplate a move – where’s that list of FIOS communities…

  24. Frank,

    Ditto, I watch HD movies on my Apple TV. At around 5-6Mbps for an HD h.264 stream, I need something as fast as that or faster to watch the movie while its downloading. Which I can at the moment with Comcast 8Mbps cable modem service. For a 2 hour movie this is around 5GB or so, not counting the packet overhead of a few percent.

    Don’t forget that if you download this via P2P you have both your download, and your upload to get your share ratio back above one. If you share to the recommended 1.5 before you stop seeding, then you’ll have moved 2.5X the movie before you stop, or about 13-14GB. Meaning about 18 of these in a month, a lot less than one per day, would hit the cap.

    So forget IPTV if you watch anywhere near as much as the average TV consumer.

  25. “…I was shopping Amazon S3 as a secondary backup solution, but if I’m backing up my modest 200GB machine 4 times a month…”

    @Big John

    That’s all part of Comcast’s master plan! That cap will kill off anyone using Amazon S3 and also kill off UnBox! Nice huh? We can’t have anyone using reasonably price alternative to Comcastic cable now can we?

  26. Hmmm. 250 GB sounds like a lot, but how much bandwidth do I really use? I have a 360 like many of you and I have the Roku Netflix player. I just DL’ed Tiger Woods and Star Wars: Force Unleased this past weekend. Both those demos were 1GB+. I play COD4 online about 3 times a week, and I have no idea how much traffic that uses per min. I bet the bandwidth usage goes up if you are host in a game as well.

    Ok, let say that XBox Live uses around 10MB/h down and 6 MB/h up. ( And if you host in Halo 3 or CoD 4 lets just say it doubles.

    If I do around 10-15 hours of gaming / month
    10 hours of not hosting * 16MB/h (10 + 6 down/up) = 160 MB
    5 hours of hosting * 32MB/h = 160 MB
    5 full game demos =~ 5.5 GB
    5 arcade demos (500MB each) = 2.5GB
    1 HD video rental = 5 GB

    Total XBox Live Bandwidth per month: ~13 GB (just under)

    As for the Roku, it DL’s different quality content based on you connection speed. I always get the best quality so I am using 2.2 Mb/s for everything I watch on that. I just started watching Heros Season 1 and Airwolf Season 1. Those episodes are around 43 min long. I also watch a ton of movies, probably around 25/month, and say the average movie is 90min. How much bandwidth am I using.

    The math:
    2.2Mbps / 8 (bits in a byte) = .275MB/s * 60sec = 16.5MB/min * 43min = 709.5 MB/episode
    2.2Mbps / 8 (bits in a byte) = .275MB/s * 60sec = 16.5MB/min * 90min =~ 1.5 GB/movie

    So, if I watch 30 episodes of TV shows and 25 movies….
    709.5 MB * 30 = 21,285 MB =~ 21GB
    1.5GB * 25 = 37.5 GB

    Total Roku bandwith per month: 58 GB

    Lets add in web browsing, ubuntu updates and possible torrents
    Web = 500 MB
    Updates = 1 GB
    Torrents (8 * 700MB) =~ 6 GB down / 1 GB up = 7 GB

    Total other bandwidth: 8.5 GB

    Summing all bandwidth usage: 8.5 + 58 + 13 = 79.5 GB

    Disclaimers: I rounded bandwidth usage up in most places just to be safe. Also, I don’t really know the actual bandwidth requirements of XBox Live. So, all in all, it looks like you really have to abuse your network connection with massive amounts of torrents while you are sleeping and such to go over the 250GB cap. My math may be wrong somewhere in there too. Even if XBox Live traffic is double than I calculated I would still be way under, so I don’t plan on worrying about this cap. I don’t share my connection with anyone but my girlfriend and she is only a web browser. These numbers would obviously go up if you have more people using your connection. If you add in a PS3, Wii or a Slingbox may add to that total, but you would really have to push your connection to burst the bubble.


  27. In response to Comcast’s posting about the limits, I responded as follows:

    Comcast MUST provide a way to monitor TOTAL usage, including mobile devices, TiVos, etc. Telling the customer to download, install, and maintain separate tools for each PC, Mac, handheld, etc., is simply not sufficient.

    Also, why not charge fees for excess bandwidth usage? Who gains by the one-year suspension? Not the customer, not Comcast. Stiff fees are an effective deterrent that will benefit Comcast and still permit the customer to maintain service. (Electric companies, also monopolies, do not disconnect customers for excessive electric usage.)

  28. Update: It is now March. Well past the date when Comcast said a bandwidth Meter would be available. And still nothing. I assume they aren’t going to offer one.

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