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Re: Get as much IP space as you ever dreamed of, was: Re: Looking to buy IPv4 addresses from class C swamp
by Brandon Butterworth 28 Apr '03

28 Apr '03

> a german steel mill from some god- > forgotten swamp in Panama. Like: that steel mill must have moved, yeah. Sure, you can have a steel mill in your garden too - http://www.dovebid.com/Auctions/AuctionDetail.asp?auctionID=1298 brandon

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Re: Selfish routing
by Mike Lloyd 28 Apr '03

28 Apr '03

alex(a)yuriev.com wrote: > Having capacity *always* makes a network better. True enough; given massive over-capacity, you'll have a hard time finding any congestion. (Of course, you also won't find optimality without applying some kind of measurement.) But curiously, adding some incremental capacity to a network can, under some conditions, actually make it worse! Leo Bicknell wrote: > I mean, really, the fact that a secondary path is worse than a primary > path with no capacity is a no brainer, couldn't these people be doing > something more useful? Roughgarden's point (as I see it) is that Braess' paradox applies. Most people find it obvious that adding more capacity to a network will always help, but as it happens, that's not true. That is not to say that adding capacity is always wrong. It's usually right; it's just of some interest to note that there are conditions where harm can result, especially when independent actors act "selfishly". The basic result is quite old, as Roughgarden observes; the same phenomenon exists in road networks, and he gives a nice example of strings and springs in his paper, which Jeffrey Arnold cited earlier: <http://wisl.ece.cornell.edu/ECE794/Apr2/roughgarden2002.pdf> This contains a good deal more detail than the NY Times writeup that started this thread :-) As Jeffrey observed, the assumptions in the model don't map well to the Internet we all know and love, but results like Braess' paradox come up again and again. If you want an optimal network, you can: 1/ sit in the middle and play at being the God of TE 2/ have the various actors optimize "selfishly" 3/ count hops and assume that's close enough (Oh, and if you're into that sort of thing, I suppose you can try dropping some packets to speed things up.) Roughgarden's result is that 2/ is not quite as good as 1/ at making fully optimal networks, but in a bounded way. I think the bound is a really nice result, although it's a pity the model assumptions aren't all that close to the operating nature of the Internet. alex(a)yuriev.com wrote: > However, claims "we have a special technology that magically > avoids problems in the networks that we do not control" is the > egineering religion. And I wouldn't evangelize that faith, as stated. I do happen to believe in "special" (or if you prefer, "selfish") technology that measures problems in networks I do not control, and if they can be avoided (say by using a different network or a different injection point), avoid them. In practice, that extra "if" doesn't change the equation much, since: Richard A Steenbergen wrote: > Random good luck just by having lots of paths to choose > from and a way to detect which one "works"... it's possible. Quite so. I won't comment on the degree of effectiveness, since that would be marketing :-) Nobody should be surprised at what I'd say about that anyway. Mike

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RE: Looking to buy IPv4 addresses from class C swamp
by McBurnett, Jim 28 Apr '03

28 Apr '03

Yes, That is VERY TRUE.. I put a block on 4 /8s of the 11 blocks I know are APNIC blocks and cut my spam load by 70%. But it is unmanagable.... J >Out of the frying pan, into the fire. A significant number of >endpoints >block all APNIC /8's due to spam. Perhaps RIPE? > >S > >Stephen Sprunk "God does not play dice." --Albert Einstein >CCIE #3723 "God is an inveterate gambler, and He throws the >K5SSS dice at every possible opportunity." --Stephen Hawking > >

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Re: Selfish routing
by Mike Lloyd 28 Apr '03

28 Apr '03

alex(a)yuriev.com wrote: >>alex(a)yuriev.com wrote: >>>If this is the last mile which is the problem, it will >>>*always* be a problem no matter if one talks about primary >>>or secondary path. >> >>Except when the last mile has an alternate (eg, a multihomed corporate >>site). > > Nope, then you either will get the congestion inside the corporate > network ( which you should not ) or the second path actually is the > best path. OK; great. And what mechanism were you thinking of to cause your flows towards that corporation to follow the second, better path? For those following along in the general audience, imagine you have links to ISP A and ISP B, both of whom provide transit to corporation X, advertising prefix P. Do you route P into A, or into B? If the "last mile" link from A to X congests, how will you switch to the alternate? The main point here is that BGP contains no mechanism to detect and use higher performance, lower congestion paths. It's not easy to make such choices promptly, correctly and stably. Alex says that if we all just buy enough OC-192, the problem will go away; that's debatable, but immaterial, since the network is as we find it, not as we wish it to be. I take the quote above as an acknowledgement that selection of path is important, and now the question is "how?". On BGP's inherent choice quality (or lack thereof), I sent a pointer earlier to a single slide from a NANOG presentation. That makes the point that BGP generates results quite close to what you'd expect from random routing (once you make it loop free). I received requests for a pointer to a more readable presentation; for that, see the archive: <http://www.nanog.org/mtg-0206/ppt/mike1.ppt> In a separate post, alex(a)yuriev.com wrote: > I do not have anti-vendor crusade. I have a crusade against > vendors who are selling ice to the eskimo, while molding the > concept of what ice is to fit their whitepapers. I admit to being a vendor, and we do have whitepapers. That may make us inherently evil in your eyes. Fine. But what about Roughgarden? What about MIT's RON project? What about the UWash Detour project? Why are all these academic, non-commercial people pointing out that it's not a simple thing to build an optimal network, but it can be done using any of a variety of smart route selection schemes? Are all these people just dupes of some grand pro-vendor conspiracy? Or are you molding their work to fit your crusade? Mike

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Fibre management software
by Thomas Kernen 28 Apr '03

28 Apr '03

Hello, does anyone have any recommendations for fibre management software that allows the cable management from the access POPs to the customer (a pair of fibre to the customer not the actual internal building cabling) and the global metro fibre cabling. If possible that can be linked into an active network management application (directly or via some middleware). The purpose is the identify all cabling in the network (we manage the dark fibre directly) and if possible link it to the NMS platform (in an IP over optical network) TIA Thomas

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Re: Selfish routing
by Michael.Dillon＠radianz.com 28 Apr '03

28 Apr '03

>> In brief, >> the paper's says that under certain assumptions the globally optimal >> latency would be only 25% better than the selfish result. >If I might, his model says the best is between 0% and a max of 25% >better than the selfish result. Selfish routing may actually get us the >best possible Internet, although that is not proven. This sounds a lot like the 80-20 rule. Selfish routing gets you 80%. Infinite knowledge will bring you up to 100% of what is possible but that presumably costs a very large amount of money. --Michael Dillon

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Selfish routing
by Sean Donelan 27 Apr '03

27 Apr '03

How do network operators maintain "fairness" in their networks in the face of selfish behaivor? Although this article concerns some of the "smart routing" products, we see the same thing with other applications (and even malicious applications like worms). Every 5 years or so we discuss the need for something like a "penalty box" for ill behaived traffic. But in the end, that's too hard. Its easier to add capacity than to solve the fairness problem. http://www.nytimes.com/2003/04/24/technology/circuits/24next.html Like motorists who cut off other cars as they swerve onto residential streets to speed their own trips, an Internet based on what Dr. Roughgarden and Dr. Tardos call "selfish routing" might indeed speed up the journeys of some data packets. But over all, the two researchers found, the result is quite different. Those shortcuts through side streets often have the effect of delaying other drivers, or in the Internet's case, packets. [...] One antidote to selfish routing, the two researchers found, is more capacity. Optimum overall system speeds can be restored despite selfish routing by either doubling the number of lanes on a highway or doubling the bandwidth of a communications link. Particularly in the case of roads, however, that is rarely practical or even desirable.

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level3 thoughts
by matthew zeier 26 Apr '03

26 Apr '03

Investigating Level3 as an upstream provider (oc12 or more). Any recommendations for or against? Related, what are they doing with Genuity's network? -- matthew zeier - "Curiosity is a willing, a proud, an eager confession of ignorance." - Leonard Rubenstein

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nodecontrol
by Ingo Flaschberger 26 Apr '03

26 Apr '03

Hi i develope a device for remote out- and in- of band management for internet nodes. more information: nodecontrol.sil.at systemtest: 62.116.6.11 / telnet / test / test plz no flames, i will not post about that again. Kind regards, Flaschberger Ingo -- we own the fibre; 9.6.98 illiad

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RE: 60 Hudson
by Todd A. Blank 25 Apr '03

25 Apr '03

Correct me if I am wrong, but the FiberNet to which you are referring in 60 Hudson is a different "FiberNet" than the one that was headquartered in Columbus, OH and recently sold to Cogent. As far as I know, they (the FiberNet in Columbus) are not out of business, unless selling to or being taken over by Cogent is synonymous with "going out of business" :-) This is not in defense or support of either of these organizations. It is merely a clarification of the facts. Maybe Drew is trying a new variation on the "Joe Job" thing :-) Sincerely, Todd A. Blank IPOutlet LLC -----Original Message----- From: Drew Weaver [mailto:drew.weaver@thenap.com] Sent: Friday, April 25, 2003 12:57 PM To: 'Jeffrey Meltzer' Cc: 'nanog(a)merit.edu' Subject: RE: 60 Hudson This might explain why fiber net went out of business and sold to cogent?? -Drew -----Original Message----- From: Jeffrey Meltzer [mailto:jeffrey@villageworld.com] Sent: Friday, April 25, 2003 10:32 AM To: nanog(a)merit.edu Subject: Re: 60 Hudson Quick followup, apparently the current issue i'm having with them is a "bad oc48 card" (again, shocker), and they don't have one in stock, and had to put a "rush order" in for a new one...You'd think a carrier would keep this sort of thing in stock. Went down late yesterday afternoon, and with this being Friday, i'm sure this won't be fixed until late Monday. Use this as an indicator before choosing FiberNet :) Jeff -- Jeffrey Meltzer Network Services Manager ICS/VillageNet 631.218.0700 On Fri, Apr 25, 2003 at 09:42:22AM -0400, Jeffrey Meltzer wrote: > > As someone who uses FiberNet in 60 Hudson (and ethernet link back to 25 > Broadway) i'd say avoid them like the plague. In the ~6 months that i've > had this circuit (aparently it's provisioned over an OC48), it's gone down > at least 4 times, possibly more, sometimes for upwards of 12 hours at a time > (starts at 10% packet loss, then just keeps growing). Their answer every > times has been "bad OC48 card". I don't know whether that's just the line > they're feeding me (I have a feeling it is), or their hardware vendor is > just garbage, but they don't appear to have the ability to keep this circuit > up for more than 3 weeks at a time. > > At one point they sold us on upgrading it from Ethernet to FastE, we said ok > maybe that will be better. However, they took down the 10M link at around 9pm > on a Friday night, and by 7pm Sunday night they hadn't had the 100M link up > yet so we just told them to forget it... > > Since the circuit is just backup, i've been testing FiberNet as fo late. > Yesterday, after I started seeing packet loss I waited at least 2 hours to > call them, to see if they'd notice the issue themselves. Of course as usual > they didn't. > > I'm fairly sure i'm the only customer they are providing this > service to between 25B and 60H, otherwise for sure they'd know by know > (unless they are dedicating a full OC48 to my 10M link, which would be a > whole other story itself). > > I'm unsure, however, if this is how they provision service inside (suite to > suite) 60 Hudson, it'd be fairly strange if they did, but FiberNet is > turning out to be a fairly strange company. > > ..just my experience :) > > JEFF > > -- > Jeffrey Meltzer > Network Services Manager > ICS/VillageNet > 631-218-0700 > > On Wed, 16 Apr 2003, Simon Lockhart wrote: > > > Speaking to Level3, they're saying that the Fibernet suite on the 1st floor > > is the best place for interconnects to other suites in the building.

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