Actually, the Internet IS a series of tubes…

Alaska’s Senior Senator Ted Stevens was widely disparaged for a speech he gave back in June of 2006 when he compared the Internet as a “series of tubes“[1].  The backlash against the comment was quite remarkable, IMHO. People seemed to believe that this was an example of how stupid senators could be when dealing with technology (John Stewart did an awesome bit on it where he got John Hodgeman to admit “I’m a PC” on TDS (I can’t find a link to the video unfortunately)).

The other day, I was chatting with a developer from the networking group, and I commented to him that I thought that Stevens was right.  The Internet really IS a series of tubes.  The other developer looked at me strangely until I explained my reasoning to him.


If I was to describe the whole “Net Neutrality” debate (a subject on which I am completely agnostic) to a layman, I think I’d end up describing it by using something like the “series of tubes” analogy (I’d probably talk about pipes and hoses though).

It turns out that when discussing bandwidth, pipes that carry water almost perfectly model the Internet.  Bigger pipes can carry more water, smaller pipes can carry less water.  There’s no way of forcing more water through a pipe than the pipe can physically hold, and you simply aren’t going to get 1Mb/s download rates through a 56kb/s modem.    Similarly, pipes don’t have to be filled to capacity – you don’t have to use the bandwidth.

You could model the Internet as a series of interconnected pipes of varying diameters and length which carry data from the servers to the client computer, and not be too far wrong.  Water (data) flows more quickly through the larger pipes and slower through the smaller pipes.  Since the pipes are interconnected, data can travel via multiple paths between the server and the client, choosing the optimal path.  If large sections of the pipes are blocked (water main breaks), the data is redirected via another path, potentially at a loss of bandwidth.


If you think about the Internet as a series of pipes, the “Net Neutrality” debate then boils down to a discussion about allowing paying customers to reserve space within the pipes (which reduces the capacity that the non paying customers have available) or equivalently allowing paying customers to use alternate pipes that are only available to those customers (thus allowing the companies to reduce the size of the pipe that’s available for the non paying customers, since they don’t use as much bandwidth as the paying customers).  The people who are in favor of “Net Neutrality” want to force the pipe companies to keep the high volume traffic on the same pipes as their traffic (thus enabling more bandwidth for everyone), the people who oppose “Net Neutrality” (mostly the people who own the pipes) want to build an mechanism that allows them to gain additional revenue from the people who put the most data into their pipes.


If I had to guess, Stevens asked one of his staffers to explain the “Net Neutrality” issue to him, and the staffer came up with the “series of tubes” as a way of explaining it to Stevens, then Stevens ran with the idea, much to his later embarrassment.


[1] I am now officially flabbergasted.  The wikipedia has an article explicitly about “a series of tubes”.  For the record, I wrote this post before I read it (since some of my comments above are reflected in the article).

Comments (26)

  1. I still think roads, Highways and freeways are the best description.  

  2. Jason says:

    Different amounts of water can go through the same pipe based on water pressure, all the way up to the point where the material that makes up the pipe meets its breaking point.  So a small metal pipe can carry much more water per unit of time than a plastic pipe several times the metal pipe’s diameter.  While you can try to map this to the type of link (copper, fiber, etc), it gets too complex and the simplicity that makes the analogy attractive gets lost.  

    In general I hate analogies because they are usually used to either abstract away inconvenient details or to make use to something in the analogy that doesn’t map to the original and try to use it to prove a point that it really shouldn’t be used to prove.

  3. ajb says:


    I agree with your comments about the Tubes analogy.  However, I don’t think you described the Net Neutrality debate as well.

    As an internet user, I pay my ISP for some ‘use of the tubes’, and a ‘tube to my living room’.  The web sites pay their service providers for larger tubes to their servers.  We’ve both paid for our bandwidth.

    Net neutrality really boils down to:

    Can my ISP charge me more for downloading one substance (say, Coke) through the tubes than they would charge me for another (eg Water). or can they block certain substances entirely (eg Pepsi).  (I am assuming neither substance clogs up the tubes more than any other).

    I don’t dispute the ISP’s right to charge me more for more bandwidth.  If they want to charge me more because I am downloading 10 GB a day, that is reasonable.  If they want to charge me more for having a 10MB Skype conversation than downloading a 10MB file, that seems wrong.  If they want to allow me to visit but not (unless google pays them a fee), that seems wrong.

  4. olle says:

    Actually, bigger pipes can carry more water but not any faster than smaller pipes. It is pipes carrying water under higher pressure that carry water more quickly, so the physics of your analogy is a bit off.

    Sorry, the "series of tubes" analogy for packet-switched networks just isn’t a very good one.

  5. Steve Boyko says:

    But when the "water main" breaks, whose floor do the bits flood onto?

    For the record, I always talk about the "last mile" connection to the Internet as a pipe. I think the analogy works well there. It doesn’t work as well when you talk about how data gets from somebody’s web server to your computer.

  6. Ken says:

    I’d like to second Aaron’s response.  

    The problem with the tube and water analogy is that you get pressure in an enclosed space like a tube.  If you start shrinking the size of the tube or, say, put a nozzle on it, and keep the pressure constant, the speed of the water flowing through the tube increases.  You can even get that water up to enough speed to cut most material (i.e. water jet cutter).

    On the other hand, you take all that traffic on the highway and move it onto a side street with a much lower speed limit, the traffic slows down and can even start backing up the highway.

  7. Adrian says:

    That doesn’t really explain net neutrality.  There’s already tiered pricing for bandwidth.  I’m pretty certain Microsoft and Google and Yahoo! each pay a lot more for their network access than I do for my piddly DSL line.

    That’s like paying for the size of your access point to the network of pipes.  If you want to push or pull more water through, you’re going to have to pay for a bigger connection.

    Neutrality is not-discriminating against water based on the sender or receiver once it’s in the pipes.

    "Series of tubes" is a good sound bite for recalling Senator Steven’s remarks.  The whole bit is much more absurd.  It shows that he doesn’t really understand the technology, yet he’s on the committee that could potentially write regulations for it.

  8. ajb: It’s my understanding that the Net Neutrality debate isn’t about the individual consumer.  It’s about whether or not the big name bandwidth consumers (think YouTube or other streaming video sites) can pay a higher rate to get guaranteed bandwidth.  The problem with this is that since there is only a fixed amount of bandwidth available, if the big guys get to reserve some percentage of the bandwidth, the little guys (individual consumers) get screwed because they can’t use the bandwidth.

  9. Mike Dimmick says:

    Yes, Larry, but who pays in the end? It’s still the consumers.

  10. Norman Diamond says:

    Here’s another reason why the highway analogy is better than the pipe analogy.  Some highways are free, some are toll.  In some countries all limited-access highways are toll; in others, some at random are toll and others at random are free.

    Of course, free doesn’t mean free as in speech, it means free as in beer.  Taxpayers voluntarily agreed to donate beer for drivers on some highways but not on other highways.  Oops, my cynicism is showing.  Anyway, net non-neutrality would be a lot like the random situation.

  11. Adrian, there’s one critical difference.  Microsoft and Google undoubtedly pay a TON of money for their bandwidth.

    But none of their bandwidth is guaranteed – in other words they’re paying for the amount of water they put into the pipes, but they have no guarantees that they’ll be able to put all the water that they want to into the pipes.  The telco’s want to let MS & Google & NBC & CBS & FOX & whoever pay extras to be guaranteed that they’ll get the traffic to your house reliably – right now they only give a good-faith effort.

  12. I agree that the "series of tubes" analogy was actually a pretty good one.  Stevens deserved the razzing he got because that analogy was sandwiched into a rambling complaint from him that video traffic was slowing down the delivery of email, something that is not accurate.  AFAIK, America’s internet is not being used at capacity and the delay Stevens had with receiving his email (as we all know) was almost certainly due to issues with the sending or receiving mail server.  

    Also, keep in mind that Stevens referred to sending an email as "sending an internet".  He deserved the notoriety he got.

  13. Cheong says:

    Actually, I’d think the concern of Net Neutrality is about this can be used as a step towards content censorship in the internet. (Afterall, in your "tube/pipe model" all water in the tubes/pipes are water. )

    It’s okay for ISPs to have concern over the amount of network traffic, but it’ll certainly upset some customer of they found someone is monitoring what they’re talking/transferring. And quite some people will be upset to found that one day they can no longer download anything via warez sites, because NN is no longer observed by the ISP and the ISP are now responsible for suppressing the act of illegal download. I’d think those are the reasons for most people who object it.

  14. Jim Lyon says:

    Larry, ajb has the right idea. While the telco’s are using the thought of charging big names extra as the selling point, they’re really after something different.

    Once they’ve established that it’s OK to discriminate against certain packets, what they really want is to prohibit (or charge more for) packets that undermine their other businesses. Who’ll pay 90 cents per minute for a call to Austrailia when VoIP works seamlessly? Who’ll pay for premium cable if you could get similar service cheaper via IP download?

    If it were really about giving reserved bandwidth to the big names, you’d see them clamoring for non-neutrality. As it is, they’re uniformly for preserving neutrality.

    For a look at how non-neutrality plays out, just check the conditions on data service with most cell phones. Unless you pay an arm and a leg, they restrict you to just http (text and images) and email. They do their best to restrict everything else, especially streaming audio. (Why give it to you for free when you might otherwise pay 31 cents/minute?) (And if I try to run Skype on my cell phone, the connection gets made but the audio mysteriously disappears after 5 secxonds.)

    In short, non-neutrality is not about serving you better; it’s about extracting more money from a (mostly) captive audience.

  15. Norman Diamond says:

    > The telco’s want to let MS & Google & NBC & CBS & FOX &

    > whoever pay extras to be guaranteed that they’ll get the

    > traffic to your house reliably

    Yuk.  The obvious problem is that, no matter how good that is in principle, who’s going to enforce the principle.  Odds are that the "best efforts" in ordinary transactions will turn into "best smokescreens to hide deliberately crippled efforts".  As for the principle itself, it does sound good, but I wonder how they could deliver it.  If Google in South Korea pays for guarantees, how will that force satellite receivers in Mongolia or censors in Saudia Arabia to deliver on the guarantees?

    Monday, July 30, 2007 9:44 PM by Patrick Farrell

    > rambling complaint from him that video traffic was slowing

    > down the delivery of email, something that is not accurate

    That ramble is likely inaccurate on routes where every leg is underutilized, but again, what happens when passing through a constricted leg?  It was stated that Stevens comes from Alaska.  Does every provincial town in Alaska have fat pipes to the backbone?  Does someone know for sure that they don’t have the same limitations as backwater areas in other countries?

    Here’s another analogy.  Attach a device that your Windows system hasn’t seen before, and it spends a few minutes dedicating CPU and disk operations to searching for a driver.  Even a talented Microsoft employee blogged recently that he couldn’t figure out why his PC slowed to a crawl for a few minutes after he connected an external monitor.  No matter what the bandwidth of your CPU or disk accesses or network connection, if you use a big enough fraction of it then the big users will slow down the little users.

    > Also, keep in mind that Stevens referred to sending an email

    > as "sending an internet".

    Do I see someone referring to sending an e-mail message as "sending an email"?  Maybe some razzing is called for, though to a lesser degree.  Let’s upload an ftp.

  16. Leo Davidson says:

    I think it’s a perfectly good analogy. People rejecting it seem to expect analogies to be exact replicas of a situation in another domain but they don’t have to be that to be useful. Analogies are just rough tools for allowing people to think about something and grasp the very fundamentals of something unfamiliar. If you dig deep enough then all analogies fall apart because, shockingly, they’re not descriptions of the exact same thing they’re being used to illustrate. Nobody hears an analogy and thinks that gives them a full, deep understanding of something. It’s just a starting point.

  17. AndyC says:

    The analogy itself is reasonably sound and works well as a non-technical explanation. The problem was that Stevens was stretching it too hard, which just served to demonstrate how little he knew about what he was saying. For that he deserved most of the ridicule he got.

  18. Adrian says:

    Larry said:  "But none of their bandwidth is guaranteed – in other words they’re paying for the amount of water they put into the pipes, but they have no guarantees that they’ll be able to put all the water that they want to into the pipes."

    I find it hard to believe there isn’t an service level agreement on high-end connections the big players pay for.

    And I think you’re incorrect that net neutrality is about guaranteed bandwidth.  It’s not about how much data you can pump into the network.   It’s about how well your packets get routed.  If Portal G pays a premium, the ISPs will make sure those packets are delivered to the end user faster than those from Portal Y, who didn’t pay the premium.

  19. This would (of course?) be the Senator Stevens whose house was just searched by the FBI.

  20. Frank, and that has nothing to do with whether or not his analogy was accurate.

    I try VERY hard to stay away from politics on this blog.

  21. Mihai says:

    The "series of tubes" thing is news only for noobs.

    The old generation knows that it was always about pipes and liquids:

  22. foxyshadis says:

    You can think of it in a more concrete way too: The internet really is a series of tubes, long tubes housing copper and fiber buried several feet underground and criss-crossing the country, and in cities for fiber/cable and where phone poles are impractical. That doesn’t really say anything about the net neutrality debate though. :p

  23. Norman Diamond says:

    > I try VERY hard to stay away from politics on this blog.

    Oh?  The base note started:

    > Alaska’s Senior Senator Ted Stevens

    instead of "Some random person Ted Stevens".  I agree with you that Frank Wilhoit’s comment had nothing to do with whether the analogy was accurate, but the comment was a lot less political than the base note.  The FBI’s antics are more outrageous than politicians, but that doesn’t make them political.

  24. Norman Diamond says:

    Tuesday, July 31, 2007 2:02 PM by foxyshadis

    > criss-crossing the country

    Last I heard, the internet spread to other countries too, and even into the New World.  In fact if one studies ancient history and supposes that some features of the internet existed before the web, then one might have to judge that some features of the internet were even invented in other countries instead of being 100% Swiss.

  25. Norman, acknowledging someone’s job isn’t political.  Calling Bill Clinton the "Adulterer In Chief" is political (which is not intended to be a statement about Clinton, it’s just an example of a politically tinged reference).  Whether you like it or not, Ted Stevens IS the senior senator from the state of Alaska.

  26. nikita nipone says:

    Microsft pays more for its bandwidth because every microsoftie gets 1 MByte/sec connection to the entire internet (except to some poor countries where they have a single 56K modem connection to the internet).

    In Korea people have 2 GB/s connection to their homes and the internet is cheap, but in the rest of the world it is not so cheap.

    Now, the internet has grown larger and eventually you will be able to buy an IP phone and walk around the world with your phone and talk through WI FI and WI MAX for free. Telecommunication companies are scared that their revenue will plummet and they are trying legislators to stop the technical advances by law, simply restricting the kind of traffic you can get through TCP/IP.

    I think telecos are doomed and they should move as fast as they can onto new technologies and new markets, like IPTV.

    If they can win in some countries and convince legislators to create monopolies, they will fail in other countries. Countries with fewer regulations will flourish and have better technology than those with monopolies. Eventually all countries will follow the leader, so I agree with Larry that in this case it is better to be agnostic and see what happens.