Re: Internet "architecture"
Jon Crowcroft <[email protected]>
| Newsgroups | gmane.network.end2end |
|---|---|
| Message-ID | <CAEeTejL2EMMEi9e6d6UE-5y_dvWkKbJ1tPKTSg+uX4vVM-+2+w@mail.gmail.com> |
I think you can look at it a different way - SDN lets you move even more smarts out of the network into end systems - as far as we implement it, that looks even less like the ITU than the current ancient-route-computation/firewall/middlebox ridden IPv4 ossification of today so i can see that you could cast SDN in the Wicked Witch of the ITU role, but equally, I think of it as not being in Kansas anymore.... cheers jon On Sat, Apr 13, 2013 at 10:39 PM, John Day <[email protected]> wrote: > Yea, I have seen their stuff too, pretty amusing. about as disruptive as a > speed bump. ;-) > > Actually you have it backwards, we *are* using the reactionary designs of > 40 years ago and that is what is holding things back, rather than the > forward looking designs that were being pursued. > > Those weren't the answer, but it was on the way to the answer, that is > clear now and they would have found it if they had been able to keep going. > > Things become much simpler once you are out of the ITU model that SDN and > Open Flow are locked into. > > Have fun, > John > > > > At 8:25 PM +0100 4/13/13, Jon Crowcroft wrote: > >> well i've seen scott shenker do his SDN vision talk a couple of times, >> and I know nick mckeown's work pretty well, and I do not think they >> are bell heads >> >> one point is that computer science has grown up slightly since 40+ >> years ago, so we are capabile of building way more flexible safe, >> secure and performant systems that in the past, when the design >> constraints on protocol stacks were set by 1960s ideas of s/w... >> >> so the stuff out of berkeley, stanford, princeton, gatech etc >> in this space is not constrained by the old rules >> >> it is deconstrained by new capabilities... >> >> [slightly stolen from John Doyle's cool idea of de-constraining >> constraints] >> >> >> so the realpolitik of openflow is (as it was with GSMP) to get arms >> length from the legacy router biz, and move the functionality somwhere >> where we can do disruptive innovation >> >> but that is another chapter... >> >> In missive <a062408c2cd8f33d66244@[10.0.**1.3]>, John Day typed: >> >> >>Jon. >> >> >> >>Yes, precisely. The first place it shows up is in ISDN, then Frame >> >>Relay, ATM, and MPLS. All those CCITT-like connection oriented >> >>solutions. And you undoubtedly are correct, it was brought into the >> >>Internet by the Europeans where the new model was largely ignored >> >>after the suppression of CYCLADES and the completion other early work >> >>such as the Cambridge DS. (As near as I can tell the vast majority >> >>of European universities never strayed too far from the traditional >> >>ITU model during the 70s to 90s. In fact most of the research still >> >>bears a strong mark of it with an Internet veneer.) >> >> >> >>Yes, it did arrive sometime back and has been a constant source of >> >>humor since the ATM lunacy. In fact, this is what makes it so >> >>wonderful that OpenFlow and SDN have embraced the ITU world view so >> >>completely. The Internet becomes about as anti-Internet as it can >> >>get. The Bell-heads have taken over. You have to admit it is pretty >> >>amusing. >> >> >> >>Take care, >> >>John >> >> >> >> >> >>At 12:29 PM +0100 4/13/13, Jon Crowcroft wrote: >> >>>so the dogma here was that the business of manageing the net was just >> >>>another distributed system (see the Cambridge Distributed System) >> >>>wherre name services, router services, security services were >> >>>implemented in exactly the same way as any other distributred system >> >>>(file systems, transaction services, distributed computation tools)... >> >>> >> >>>but the control plane model of the net arrived in internet-land some >> >>>time back - for example simon crosby took ideas (this was around the >> >>>time when everyone was trying to do IP over ATM, which morphed into >> >>>mpls) from "switchlet" territory with remote computation as >> >>>controlplanestechnology...**other people, e.g. ipsilon, also took the >> >>>seperation of concerns that are >> >>>forwarding packets as fast as you can, >> >>>from >> >>>working out where they should and shouldn't go >> >>>and put them on different boxes, originally to be coordinated via the >> >>>Generic Switch Management Protocol >> >>>later re-discoverd as Software Definted Networkign and Openflow... >> >>> >> >>>plus ca change... >> >>>In missive <a062408a1cd8ddf0a5bcd@[10.0.**1.3]>, John Day typed: >> >>> >> >>> >>The whole distinction of data plane and control plane arises with >> >>> >>ISDN. It is a CCITT concept and was never used to describe >> anything >> >>> >>Internet related, either in the US or Europe. Such distinctions >> only >> >>> >>make sense in the beads-on-a-string models of the ITU. Routing, >> >>> >>ICMP, DHCP, etc. type functions were characterized as layer >> >>> >>management, which can exist to greater or lesser degree in all >> layers >> >>> >>and must be within the layer owing to the different scopes of the >> >>> >>layers. >> >>> >> >> >>> >>Take care, >> >>> >>John Day >> >>> >> >> >>> >>> >> >>> >>>the post-hoc rationalisation phrase is way too glib....certainly >> not >> >>> >>>intended to be rude to people that created this cool stuff we all >> >>> >>>use - in fact i was conflating three things >> >>> >>> >> >>> >>>1. a bunch of work fairly recently on optimal protocols and >> narrow >> >>> >>>waist of the hour glass... >> >>> >>>2. the ordering of constrints on the design of the internet >> >>> >>>protocols (as per dave clarks 88 paper) >> >>> >>>and >> >>> >>>3. the apparent simplicity of IP - my missing point was that the >> >>> >>>complexity pops out somewhere, and that place is in the control >> >>> >>>plane....as we've since disovered... >> >>> >>> >> >>> >>>of course, there were people that ran dynamic distributed routing >> >>> >>>for VC networks (X.25 for example - we had switches in the JANET >> >>> >>>network that did this) so they were even more complex in both >> data >> >>> >>>and control plane (what with crankback etc etc:) >> >>> >>> >> >>> >>>so yes, a bit glib really...sorry >> >>> >>> >> >>> >>>normal service will be resumed as soon as I get my IPTV QoS back >> :) >> >>> >>> >> >>> >>>j. >> >>> >>> >> >>> >>> >> >>> >>>On Fri, Apr 12, 2013 at 3:07 PM, Fred Baker (fred) >> >>> >>><<mailto:[email protected]>fre**[email protected] <[email protected]>> >> wrote: >> >>> >>> >> >>> >>>I'd suggest running the assertion by Vint. I made a similar >> >>> >>>assertion in a document not too long ago, which I ran by him for >> >>> >>>comment, and he told me I was flatly wrong. Yes, the circuit >> switch >> >>> >>>folks were using the term "catenet" to refer to networks that >> >>> >>>interoperated through translation, such as frame relay/ATM >> >>> >>>interoperation, he asserted, but at least some (he?) was using >> the >> >>> >>>term "Internet" as early as the mid 1970's. >> >>> >>> >> >>> >>> >> >>> >>>On Apr 11, 2013, at 8:59 PM, Dave Crocker >> >>> >>><<mailto:[email protected]>**[email protected]<[email protected]>> >> wrote: >> >>> >>> >> >>> >>>> This is a risky query. There have been previous threads about >> >>> >>>>such things as the "start" of the Internet. Instead, I want to >> ask >> >>> >>>>about the "architecture" of the Internet. >> >>> >>>> >> >>> >>>> Here's a comment that I sent earlier today, to a non-technical >> >>> >>>>person who is aware of the overall Internet timeline, but I >> believe >> >>> >>>>does not understand what is distinctive about Internet >> >>> >>>>'architecture'. I'm curious about reactions on this list, and >> any >> >>> >>>>possible improvements -- including complete replacement -- but >> more >> >>> >>>>importantly I'm interested in filling in the details: >> >>> >>> > >> >>> >>>> The original use of the term Internet was to describe a >> >>> >>>>distinctive technical design for a distributed, scalable data >> >>> >>>>exchange fabric. Its design characteristics differ dramatically >> >>> >>>>from those of its predecessor, the Arpanet, and from other >> related >> >>> >>>>efforts. >> >>> >>>> >> >>> >>>> That's what I sent. To prime the pump for the detail: >> >>> >>>> >> >>> >>>> By saying 'fabric' I meant to distinguish the mechanism >> for >> >>> >>>>moving raw data from the applications that used it. What I'd >> class >> >>> >>>>as distinctive were the TCP/IP separation, the remarkably modest >> >>> >>>>functionality of IP, even to the point of moving it's control >> plane >> >>> >>>>to the next level up with ICMP, and continuing with modest >> >>> >>>>expectations the layer below (which made it possible to operate >> >>> >>>>over any medium including birds.) This is usually >> characterized as >> >>> >>>>moving robustness to the edges. >> >>> >>>> >> >>> >>>> >> >>> >>>> Thoughts? >> >>> >>>> >> >>> >>>> d/ >> >>> >>>> >> >>> >>>> -- >> >>> >>>> Dave Crocker >> >>> >>>> Brandenburg InternetWorking >> >>> >>>> <http://bbiw.net>bbiw.net >> >>> >> >> >>> >>--============_-846339397==_**ma============ >> >>> >>Content-Type: text/html; charset="us-ascii" >> >>> >> >> >>> >><!doctype html public "-//W3C//DTD W3 HTML//EN"> >> >>> >><html><head><style type="text/css"><!-- >> >>> >>blockquote, dl, ul, ol, li { padding-top: 0 ; padding-bottom: 0 } >> >>> >> --></style><title>Re: [e2e] Internet >> >>> >>"architecture"</**title></head><body> >> >>> >><div>This is a can of worms, but. . .</div> >> >>> >><div><br></div> >> >>> >><div>At 4:23 PM +0200 4/12/13, Jon Crowcroft wrote:</div> >> >>> >><blockquote type="cite" cite>the folks who called it catenet >> included >> >>> >>bob braden who was working at UCL when i was there - of course, we >> >>> >>were concatenating networks that ran other protocols (Cambridge >> Ring, >> >>> >>X.25 (transport layer relays) and so on...so perhaps I'm >> conflating >> >>> >>two things - the interconnection of multiple disprate protocol >> >>> >>systems, and the IP interconenction of multiple IP networks with >> >>> >>disparete layer 2 and below....</blockquote> >> >>> >><div><br></div> >> >>> >><div>Early on the term catenet was applied without respect to >> >>> >>connection or connectionless, but only with respect to forwarding >> vs. >> >>> >>translation (if necessary).</div> >> >>> >><div><br></div> >> >>> >><blockquote type="cite" cite><br></blockquote> >> >>> >><blockquote type="cite" cite>it is the case (as some other folks >> >>> >>privately pointed out to me) that IENs (including IEN 1 written at >> >>> >>UCL) are Internet Experiment Notes, and go back to mid 1970s, so >> i'm >> >>> >>wrong to say "internet"</**blockquote> >> >>> >><blockquote type="cite" cite><br></blockquote> >> >>> >><blockquote type="cite" cite>however, my point about parsimony is >> >>> >>really over compressed - IP trades off simplicity in the data >> plane, >> >>> >>for complexity in the control plane - its not a pure trade off >> (it can >> >>> >>be seen partly as a win-win, as signaling protocols for VC >> networks >> >>> >>can be nearly as complex (or in X.25 and B-ISDN's Q.2931's cases, >> more >> >>> >>complex) as routing protocols....nevertheless, getting routing >> right >> >>> >>and all associated components is seriously non-trivial - other >> systems >> >>> >>(the aforesaid cambridge ring protocol stack) represent a >> different >> >>> >>trade off that is also quite elegant.</blockquote> >> >>> >><div><br></div> >> >>> >><div>The whole distinction of data plane and control plane arises >> with >> >>> >>ISDN. It is a CCITT concept and was never used to describe >> anything >> >>> >>Internet related, either in the US or Europe. Such distinctions >> only >> >>> >>make sense in the beads-on-a-string models of the ITU. >> Routing, >> >>> >>ICMP, DHCP, etc. type functions were characterized as layer >> >>> >>management, which can exist to greater or lesser degree in all >> layers >> >>> >>and must be within the layer owing to the different scopes of the >> >>> >>layers.</div> >> >>> >><div><br></div> >> >>> >><div>Take care,</div> >> >>> >><div>John Day</div> >> >>> >><div><br></div> >> >>> >><blockquote type="cite" cite><br></blockquote> >> >>> >><blockquote type="cite" cite>the post-hoc rationalisation phrase >> is >> >>> >>way too glib....certainly not intended to be rude to people that >> >>> >>created this cool stuff we all use - in fact i was conflating >> three >> >>> >>things</blockquote> >> >>> >><blockquote type="cite" cite><br></blockquote> >> >>> >><blockquote type="cite" cite>1. a bunch of work fairly recently on >> >>> >>optimal protocols and narrow waist of the hour >> glass...</blockquote> >> >>> >><blockquote type="cite" cite>2. the ordering of constrints on the >> >>> >>design of the internet protocols (as per dave clarks 88 >> >>> >>paper)</blockquote> >> >>> >><blockquote type="cite" cite>and</blockquote> >> >>> >><blockquote type="cite" cite>3. the apparent simplicity of IP - my >> >>> >>missing point was that the complexity pops out somewhere, and that >> >>> >>place is in the control plane....as we've since >> >>> >>disovered...</blockquote> >> >>> >><blockquote type="cite" cite><br></blockquote> >> >>> >><blockquote type="cite" cite>of course, there were people that ran >> >>> >>dynamic distributed routing for VC networks (X.25 for example - >> we had >> >>> >>switches in the JANET network that did this) so they were even >> more >> >>> >>complex in both data and control plane (what with crankback etc >> >>> >>etc:)</blockquote> >> >>> >><blockquote type="cite" cite><br></blockquote> >> >>> >><blockquote type="cite" cite>so yes, a bit glib >> >>> >>really...sorry</blockquote> >> >>> >><blockquote type="cite" cite><br></blockquote> >> >>> >><blockquote type="cite" cite>normal service will be resumed as >> soon as >> >>> >>I get my IPTV QoS back :)</blockquote> >> >>> >><blockquote type="cite" cite><br></blockquote> >> >>> >><blockquote type="cite" cite>j.</blockquote> >> >>> >><blockquote type="cite" cite><br> >> >>> >><br> >> >>> >></blockquote> >> >>> >><blockquote type="cite" cite>On Fri, Apr 12, 2013 at 3:07 PM, Fred >> >>> >>Baker (fred) <<a href="mailto:[email protected]">f**[email protected]<[email protected]> >> </a>> >> >>> >>wrote:<br> >> >>> >><blockquote>I'd suggest running the assertion by Vint. I made a >> >>> >>similar assertion in a document not too long ago, which I ran by >> him >> >>> >>for comment, and he told me I was flatly wrong. Yes, the circuit >> >>> >>switch folks were using the term "catenet" to refer to >> >>> >>networks that interoperated through translation, such as frame >> >>> >>relay/ATM interoperation, he asserted, but at least some (he?) was >> >>> >>using the term "Internet" as early as the mid >> 1970's.<br> >> >>> >></blockquote> >> >>> >><blockquote><br> >> >>> >>On Apr 11, 2013, at 8:59 PM, Dave Crocker <<a >> >>> >>href="mailto:dhc2@dcrocker.**net <[email protected]>"> >> [email protected]</a>> wrote:<br> >> >>> >><br> >> >>> >>> This is a risky query. There have been previous threads >> >>> >>about such things as the "start" of the Internet. >> >>> >> Instead, I want to ask about the "architecture" >> of the >> >>> >>Internet.<br> >> >>> >>><br> >> >>> >>> Here's a comment that I sent earlier today, to a >> non-technical >> >>> >>person who is aware of the overall Internet timeline, but I >> believe >> >>> >>does not understand what is distinctive about Internet >> 'architecture'. >> >>> >> I'm curious about reactions on this list, and any possible >> >>> >>improvements -- including complete replacement -- but more >> importantly >> >>> >>I'm interested in filling in the details:</blockquote> >> >>> >><blockquote>><br> >> >>> >>> The original use of the term >> Internet was >> >>> >>to describe a distinctive technical design for a distributed, >> scalable >> >>> >>data exchange fabric. Its design characteristics differ >> >>> >>dramatically from those of its predecessor, the Arpanet, and from >> >>> >>other related efforts.<br> >> >>> >>><br> >> >>> >>> That's what I sent. To prime the pump for the >> detail:<br> >> >>> >>><br> >> >>> >>> By saying 'fabric' I meant to >> distinguish >> >>> >>the mechanism for moving raw data from the applications that used >> it. >> >>> >> What I'd class as distinctive were the TCP/IP separation, >> the >> >>> >>remarkably modest functionality of IP, even to the point of moving >> >>> >>it's control plane to the next level up with ICMP, and continuing >> with >> >>> >>modest expectations the layer below (which made it possible to >> operate >> >>> >>over any medium including birds.) This is usually >> characterized >> >>> >>as moving robustness to the edges.<br> >> >>> >>><br> >> >>> >>><br> >> >>> >>> Thoughts?<br> >> >>> >>><br> >> >>> >>> d/<br> >> >>> >>><br> >> >>> >>> --<br> >> >>> >>> Dave Crocker<br> >> >>> >>> Brandenburg InternetWorking<br> >> >>> >>> <a href="http://bbiw.net">bbiw.**net <http://bbiw.net> >> </a></blockquote> >> >>> >></blockquote> >> >>> >><div><br></div> >> >>> >></body> >> >>> >></html> >> >>> >>--============_-846339397==_**ma============-- >> >>> >> >>> cheers >> >>> >> >>> jon >> >> >> >> cheers >> >> jon >> > >