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Networking The Internet United Kingdom Technology

BT Begins Customer Tests of Carrier Grade NAT 338

Posted by timothy from the party-line-but-with-less-yelling dept.
judgecorp writes "BT Retail has started testing Carrier Grade NAT (CGNAT) with its customer. CGNAT is a controversial practice, in which IP addresses are shared between customers, limiting what customers can do on the open Internet. Although CGNAT goes against the Internet's original end-to-end principles, ISPs say they are forced to use it because IPv4 addresses are running out, and IPv6 is not widely implemented. BT's subsidiary PlusNet has already carried out CGNAT trials, and now BT is trying it on "Option 1" customers who pay for low Internet usage."
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BT Begins Customer Tests of Carrier Grade NAT More

BT Begins Customer Tests of Carrier Grade NAT

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  • Priority Failure. (Score:5, Insightful)

    by Anonymous Coward on Tuesday May 07, 2013 @09:30AM (#43652665)

    If people had spent as much money on IP6 as they have on NAT, we'd be done by now.

    • Businesses make money by charging people for scarce resources. IPV6 addresses are in no way scarce, so why would they invest any money in that?

      With NAT, they can keep making money the way they always have with minimal additional investment, and they can make even more money by offering dedicated IPV4 addresses to people who pay extra for some kind of "platinum premium plus pro" plan.

      • Businesses make money by charging people for scarce resources

        uh, no. businesses make money by providing value which customers then pay for. that doesn't mean artificially scarce resources, which aren't truly scarce. This will however, break a ton of shit very quickly.

        • Re:Priority Failure. (Score:5, Insightful)

          by Noughmad ( 1044096 ) <miha.cancula@gmail.com> on Tuesday May 07, 2013 @10:00AM (#43653045) Homepage

          that doesn't mean artificially scarce resources, which aren't truly scarce.

          That's why those De Beers guys are so poor.

          • Wish I had some mod points. Regardless of which side of the current argument you are on, De Beers is an insane example of how a company can create artificial scarcity, and do it for over 100 years, while making boatloads of cash.

          • Re:Priority Failure. (Score:5, Insightful)

            by Sarten-X ( 1102295 ) on Tuesday May 07, 2013 @10:48AM (#43653705) Homepage

            De Beers creates artificial exclusivity, not scarcity. It's a subtle but important distinction.

            They produce a product that people value not because it's particularly rare, but because it's just uncommon enough to be a status symbol. Various substitutes can look and act similarly, so the high prices aren't justified by an actual need for the product. Rather, the need is for the brand itself, and the company creates and perpetuates the value of that brand by limiting supply. They ensure there's just enough supply to meet demand, but not enough surplus to impact the prices people are willing to pay.

            Steve Jobs understood this concept well.

            • Re:Priority Failure. (Score:4, Insightful)

              by Shompol ( 1690084 ) on Tuesday May 07, 2013 @12:01PM (#43654859)

              They produce a product ...

              diamonds is not a product, it's a mineral (aka raw material, commodity)

              that people value not because it's particularly rare, but because it's just uncommon

              and what is the difference between "rare" and "uncommon"?

              ... enough to be a status symbol.

              It is not a status symbol because it is rare or uncommon -- it is a status symbol because De Beers adverised it... as a brand! "Diamonds are Forever"???? Have you ever seen anybody advertising a commodity before? "Gold is Forever", anybody?

              Various substitutes can look and act similarly, so the high prices aren't justified by an actual need for the product.

              Excepts this product is needed practically everywhere in technology, if not for De Beers having a chock-hold on the market and inflating prices. These guys [wikipedia.org] produces a flawless artificial diamond for use in technology, and got death threats over it.

              Rather, the need is for the brand itself, and the company creates and perpetuates the value of that brand by limiting supply. They ensure there's just enough supply to meet demand, but not enough surplus to impact the prices people are willing to pay. Steve Jobs understood this concept well.

              Yes, they turned a commodity into a brand, by monopolizing 90% of supply. The problem is -- it is a commodity, a raw material needed everywhere in technology. If the price went down it could revolutionize semiconductors industry. It can also be artificially produced from graphite, but looks like that technology is going to be squashed by De Beers, much like the electric car was destroyed [youtube.com] by the oil industry.

              • Re:Priority Failure. (Score:4)

                by Noughmad ( 1044096 ) <miha.cancula@gmail.com> on Tuesday May 07, 2013 @12:12PM (#43654989) Homepage

                and what is the difference between "rare" and "uncommon"?

                Ferrari is rare. Mercedes is uncommon. Now, hand in your geek card as you obviously never played Magic: The Gathering.

              • Re:Priority Failure. (Score:5, Informative)

                by Sarten-X ( 1102295 ) on Tuesday May 07, 2013 @01:53PM (#43656393) Homepage

                diamonds is not a product, it's a mineral (aka raw material, commodity)

                Diamond is indeed a mineral, with many industrial uses. Most of the diamonds mined, though, aren't used or marketed as an exclusive product. More on this in a minute.

                and what is the difference between "rare" and "uncommon"?

                Something "rare" is hard to find, even if you have the resources to acquire it. Something "uncommon" is just something that's not commonplace. It might also be rare, but in this case (as with Apple products) the price is kept just high enough that not everybody that wants one will have the resources to get one. They're readily available, but for some reason, it's still remarkable to see one.

                To use the venerable car analogy, a DeLorean is rare, because there's so few of them in existence. A brand-new Mercedes Benz is uncommon, because it's unlikely for the average person to buy one.

                ...it is a status symbol because De Beers adverised it... as a brand!...

                Less of a brand (because diamonds don't carry a big label saying "De Beers"), but more of a specific product. The symbolism of a diamond standing for love and commitment is purely a De Beers invention. Want to impress your wife? Give her a new Mercedes. Love her forever? Give her a diamond!

                A car is just a chunk of metal, and a diamond is just a rock. A chunk of metal with the promise of reliable transportation and the luxury of comfort is a product. A rock with the symbolism of love and promise of durability is also a product.

                Have you ever seen anybody advertising a commodity before? "Gold is Forever", anybody?

                Every. Goddamned. Day.

                I work in finance, so I watch a lot of finance-oriented television. Yes, there are many companies touting their gold-related investment strategies, which basically boil down to "buy gold and make the price go up so my pre-existing gold holdings are worth more". In a way, it's similar: They're shifting the public perception of a mundane item into a valuable product.

                Excepts this product is needed practically everywhere in technology, if not for De Beers having a chock-hold on the market and inflating prices.

                There are many other [wikipedia.org] manufacturers of synthetic diamonds, perfect for industrial use. Until recently, though, the diamonds they could easily produce were all colored, which aren't as suitable for jewelry. Now Gemesis, Scio, and others can produce gem-quality colorless diamonds.

                These guys produces a flawless artificial diamond for use in technology, and got death threats over it.

                [citation needed]

                If the price went down it could revolutionize semiconductors industry.

                The price is currently a few dollars per carat, in powder form. One carat is a huge amount compared to the size of existing transistors, so it's rather ridiculous to blame the price for the lack of diamond semiconductors. Instead, it's likely the immaturity of diamond semiconductor technology [pbs.org] that holds up back:

                The combinations of the extreme properties of diamond ... suggest that diamond should out-perform nearly every other semiconducting material system for electronic applications. IN PRINCIPLE! The reality is that there are many other factors involved in developing and implementing a technology: cost, manufacturing infrastructure, investment, and knowledge base. I think it is fair to say that diamond materials need a lot more research, knowledge, and technology development before they can be considered a mature semiconducting material.

                ...that technology is going to be squashed by De Beers, much like the electric ca

        • uh, no. businesses make money by providing value which customers then pay for

          And what is of value?

          Things that are scarce.

        • Comment removed based on user account deletion

      • Because I'll switch ISPs to whomever offers me IPv6 first.

        Oh, wait, that would require that I have a choice...

        • Re: (Score:3)

          by grahamm ( 8844 )

          There are already ISPs which supply IPv6. The SixXS FAQ lists 7 in the UK (which means competitors of BT) and 14 in the USA.

    • But IPV4 was never going to run out! There were so much new blocks to free up, nobody could've seen this coming!

    • Yeah, it's sad but it was also inevitable in a world of companies driven more by selfish buisness interests than a desire to improve the system as a whole.

      The thing is NAT delivers it's benefits immediately. You deploy the NAT box and then you can connect more computers than you have IPv4 address for. Simple. Yes some applications will break, that is why if you are a provider selling service you deploy it on your lowest tier customers who are least likely to be using such applications and represent the smal

      • Re: (Score:3, Insightful)

        by rudy_wayne ( 414635 )

        Yeah, it's sad but it was also inevitable in a world of companies driven more by selfish buisness interests than a desire to improve the system as a whole.

        Unfortunately, it's not that simply. ISPs are faced with a very serious and legitimate business problem. -- switching to IPv6 is very expensive but provides no benefit to them. For example, the millions (tens of millions?, hundreds of millions??) of modems that would have to be replaced because they can only handle IPv4. These are typically supplied by the ISP. Replacing all of them is an enormous expense, and when you're done, everything works exactly the same as it did before. From a business standp

      • There's more to it than NAT vs IPv6. The reality is we'll need both in the future. Say BT switched on IPv6 tomorrow and everyone in the UK got an IPv6 address - brilliant. But that's only half of the problem, they still need access to the IPv4 internet because all those servers the world over aren't IPv6 accessible yet.

    • we would be done by now. They should have written an extension, not a replacement.

    • Re:Priority Failure. (Score:4, Interesting)

      by Bengie ( 1121981 ) on Tuesday May 07, 2013 @10:43AM (#43653619)
      They shouldn't be able to call it "Internet" access if it's not a public IP address. This means they should not be classified as an ISP because they would not be offering Internet access as their primary service, just a crippled gateway to the Internet.
  • Is the only solution. This is a stopgap measure like carpooling and congestion charges that don't actually fix the original problem of a diminishing resource.

    • Umm, carpooling and congestion charges both work. Ultimately, unless you force people to not leave their home, people still need to go to work, and there aren't very many options available for dealing with that.

      • It takes an interesting mind to watch thousands of 5-passenger cars go by with a single occupant and not think that carpooling is a solution. Just one additional passenger will double the capacity of the road.

        • So will doubling the speed of the cars.

          Or adding lanes.

          But carpooling isn't a solution unless two people are coming from the same place and going to the same place.

  • Ah, the bad old days... (Score:5, Insightful)

    by fuzzyfuzzyfungus ( 1223518 ) on Tuesday May 07, 2013 @09:31AM (#43652679) Journal

    Fantastic! This will be just as wonderful as AOL was, back when they were still unsure about this whole 'ISP' fad, and offered ghastly semi-access to the internet proper. I think I just threw up in my mouth from all the nostalgia!

    • Re: (Score:2, Funny)

      by Anonymous Coward

      Fantastic! This will be just as wonderful as AOL was, back when they were still unsure about this whole 'ISP' fad, and offered ghastly semi-access to the internet proper. I think I just threw up in my mouth from all the nostalgia!

      Me too!

  • I hereby declare a Jihad against BT for their infidelity about IPv6.

  • On the other hand.... (Score:5, Interesting)

    by mark-t ( 151149 ) <markt.nerdflat@com> on Tuesday May 07, 2013 @09:40AM (#43652799) Journal

    With CGN, they can't *POSSIBLY* argue that an IP address somehow is linked with a particular subscriber anymore.

    This is going to create a hell of a problem when people inside the CGN start doing stuff they aren't supposed to outside of it, and those people outside can't do anything useful with the IP that they have.

    • Given that the usual move when you have an IP and want to identify John Doe is to ask the ISP, I assume that the same principle will still work just fine. After all, if the ISP isn't keeping track of which traffic to a given IP needs to go to which subscriber, the system will break, so they will still know what the story is....

      • Re:On the other hand.... (Score:5, Insightful)

        by mark-t ( 151149 ) <markt.nerdflat@com> on Tuesday May 07, 2013 @09:58AM (#43653013) Journal

        Nope.... not remotely. Which is the whole problem.

        Because if BT implements CGN, then the IP that somebody outside ot BT would have for somebody inside of it would actually map to a whole bunch of BT subscribers. BT has no possible way to tell which subscriber utilized the IP because all of them did... possibly even all at exactly the same time, unless BT maps every subscriber to a unique global IP anyways, at which point BT doesn't gain anything by using CGN at all.

        • Re: (Score:2)

          by Imagix ( 695350 )
          Not true... the CGN unit can do a bunch of interesting things to sort this out. Assigning or hashing port numbers to source IPs, to maintaining a massive set of logs of which subscriber used which IP and port at what time. Not saying that this is a _good_ thing, but is theoretically possible.

        • My point is that, for NAT to work, the NAT system has to track activity between internal hosts sharing an external IP and the outside world in order to handle the address translation process. If it didn't, it wouldn't be able to rewrite a packet coming from the outside and send it on to the appropriate internal host.

          So, if an outside entity knows that shared IP w.x.y.z did something, BT's NAT has to know which subscriber behind the NAT was responsible, because it would otherwise be incapable of correctly se

          • The company requesting information would need to know the public facing source port and correlating time otherwise there would be no way to look up the correct state/mapping. The company requesting this information wouldn't be able to know this information unless the user was connecting directly to their servers or they themselves were playing man-in-the-middle. The former option is plausible with some activity, i.e. if a peer were directly connecting to them in a torrent, but the latter option would be ill

        • To track abuse reliablly from behind a NAT two things are required

          1: the service being abused logs port number information as well as IP and time information
          2: the NAT keeps sufficient logs to map that IP/port/time combination back to a user.

          If the NAT keeps sufficient logs then in some cases item 1 may not be required, for example if the abused service can also provide the IP the abuse was received on then that is likely to narrow things down significantly.

      • Re: (Score:2)

        by grahamm ( 8844 )

        All it means is that as well as quoting the IP address they will also have to quote the port number and an accurate time in order for the subscriber to be identified. It would also need the ISP to log the 4-tuple (Subscriber 'private' IP, External IP, External Port, TCP/UDP) for each connection as well as which private IP is allocated to each subscriber.

    • doesn't really matter, all that piracy shakedown stuff is coming to a close a prenda is being brought front and center for those specific activities. There are very, very wide implications for what is going on that will probably stop a large amount of the "piracy settlement" firms.

    • Your src port will always be from x-y on this outgoing IP address. Instead of spreading the users out horizontally by IP address, they could stack them vertically by port number.

  • No choice (Score:2, Informative)

    by markus_baertschi ( 259069 )

    The carrier has probably no choice. He can no longer get IPv4 addresses for new customers, so either he refuses customers or uses NAT to map multiple customers on the same IP.

    On the other hand, the average Joe customer will not see the difference. He can surf as before and all his apps will work as before. Some apps (mostly p2p stuff) will suffer, but most internet user don't use those.

    If you as customer do need a 'real' IP, then there always is the option to get a more expensive option.

    • If you as customer do need a 'real' IP, then there always is the option to get a more expensive option.

      There's no real need to upcharge either - customers who are negatively affected could simply be placed on a 1:1 list, and everybody else would continue to share the pool.

      But maybe they can trade the retirement system free phone service in exchange for their /8 instead.

  • Over the last eight years and my previous three ISPs, my router has never once received anything other than a 192.168.x.x or a 10.x.x.x IP address from my local ISP. Not once have I received a live & legit IPv4 address. I have to pay a lot more for those. What's the difference between this and CGNAT?

    • Re: (Score:2)

      by Imagix ( 695350 )
      Odd.. every ISP that I've had gives out public IPs. Now, they're only willing to give you 2 usually, but they're proper public IPs. I'm not counting visiting hotels and such.

    • Over the last eight years and my previous three ISPs, my router has never once received anything other than a 192.168.x.x or a 10.x.x.x IP address from my local ISP. Not once have I received a live & legit IPv4 address. I have to pay a lot more for those. What's the difference between this and CGNAT?

      You are thinking of your routers internal address, the one you use to access it from inside your home network to configure and troubleshoot. They are talking about the routers external address, the one the rest of the internet sees.

    • CGNAT is NAT for your external IP address. Your router will assign private network IP addresses so your devices on your internal network, but the external interface on your router will have a publically addressable IP address assigned by the pool allocated to your ISP. Depending on their size, they may have a pool of tens of thousands or millions of addresses to assign, but you definitely got one even if you didn't know it.

      Head on over to http://whatismyipaddress.com/ [whatismyipaddress.com] to find out.
    • It's still technically NAT, because your modem is having it's external address translated to an internet addressable address on the ISP's side. The difference is that what you are seeing is a one-to-one translation with direct passthrough of all traffic. CGNAT typically refers to a one-to-many translation, where multiple subscribers are tied to a single address, and there is no inbound traffic.
  • It's pretty easy to set up a node on Tor. We could just declare the "open internet" lost to commercial interests and do all the "interesting" stuff on an encrypted network. Sure, it's slower than an open connection, but with increasingly common cable and optical connections it's still faster than even reasonably fast DSL from a couple years back.
    • Or you know, just use one of the many IPv6 tunneling mechanisms. The issue is that many of those mechanisms use IP protocol 41, and many ISPs, modems, and routers filter out non-standard protocol traffic.

  • I've had to deal with this. (Score:5, Informative)

    by Gerafin ( 1408009 ) on Tuesday May 07, 2013 @10:03AM (#43653083)
    Having to share an IP address with tons of people is absolutely, 100% a crippling experience. There are plenty of sites (newspapers, the site I get textures from, RapidShare, etc.) who limit their services by IP address. There's nothing quite like seeing messages about how your IP has exceeded the download limit on a website you've never visited before. Also: having to deal with bans when playing online games, as many are IP-based. The impossibility of hosting your own servers for games or other purposes. BitTorrent is nigh unusable. I would not pay a dime for this kind of a service, ever again.

  • And letting us know from the get go.

    How many unscrupulous ISPs could be doing this behind closed doors right now without anyone noticing??

  • If BT required all devices on it's network to be IPv6 compliant, many existing in use devices would cease to function.
    If BT said you MUST replace your working, but not IPv6 compliant device there would be an even louder cry of EVIL!

    The situation is not very good, but there aren't any alternatives.
    This is like politics. It's not about choosing the better choice, but the less evil one.

  • Comment removed (Score:5, Interesting)

    by account_deleted ( 4530225 ) on Tuesday May 07, 2013 @10:17AM (#43653287)
    Comment removed based on user account deletion

  • No ipv6 for you (Score:3)

    by sl4shd0rk ( 755837 ) on Tuesday May 07, 2013 @10:26AM (#43653393)

    "Limiting what customers can do..." seems to be the new norm... along with with "shut up. give up rights. sign EULA"

  • CGNAT has nothing to do with End-to-end (Score:4, Informative)

    by bgt421 ( 1006945 ) on Tuesday May 07, 2013 @10:36AM (#43653537)

    The end-to-end principle has to do with where network logic is placed, not which devices are reachable, routeable, or have an IP address. As simply as possible, the end-to-end principle means that we should have smart end hosts and a dumb network. This is why routers don't guarantee packet delivery -- its up to the hosts (with TCP, et al.) to ensure this. This is in contrast to telephony networks, where the network is responsible for almost everything.

    There are good reasons to oppose CGNAT, but the "end to end principle" is not one of them.

    http://en.wikipedia.org/wiki/End-to-end_principle [wikipedia.org]
    or, if you're inclined to primary sources:
    http://groups.csail.mit.edu/ana/Publications/PubPDFs/End-to-End%20Arguments%20in%20System%20Design.pdf [mit.edu]

  • 21CN (Score:4, Informative)

    by TinheadNed ( 142620 ) on Tuesday May 07, 2013 @10:45AM (#43653651) Homepage

    Apropos of nothing, here's what BT did invest in for their "21st Century Network [wikipedia.org]".

    It's all IPv4.

  • BT and its customer (Score:3)

    by multi io ( 640409 ) <olaf.klischat@googlemail.com> on Tuesday May 07, 2013 @11:10AM (#43654099)

    BT Retail has started testing Carrier Grade NAT (CGNAT) with its customer.

    Has the customer been informed already? How does he or she take it?

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