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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: "Does TCP Need an Overhaul?" (internetevolution, via slashdot)
On Sat, 5 Apr 2008 01:02:24 -0400 "Christopher Morrow" <[email protected]> wrote: > > On Fri, Apr 4, 2008 at 9:51 PM, Paul Vixie <[email protected]> wrote: > > > (i'd hate to think that everybody would have to buy > > roberts' (anagran's) Fast Flow Technology at every node of their > > network to make this work. that doesn't sound "inexpensive" to me. > > I suppose he could try to sell it... and people with larger networks > could see if keeping state on a few million active flows per device is > 'expensive' or 'inexpensive'. Perhaps it's less expensive than it > seems as though it would. > > Oh, will this be in linecard RAM? main-cpu-RAM? calculated on > ASIC/port or overall for the whole box/system? How about deconflicting > overlapping ip-space (darn that mpls!!!) what about asymmetric flows? > > I had thought the flow-routing thing was a dead end subject long ago? > And you can't get high speeds with Ethernet; you get too many collisions. Besides, it doesn't have any fairness properties. Clearly, you need token ring. Oh yeah, they fixed those. I have no idea if it's economically feasible or not -- technology and costs change, and just because something wasn't possible 5 years ago doesn't mean it isn't possible today. It does strike me that any such scheme would be implemented on access routers, not backbone routers, for lots of good and sufficient reasons. That alone makes it more feasible. I also note that many people are using NetFlow, which shares some of the same properties as this scheme. As for the need -- well, it does deal with the BitTorrent problem, assuming that that is indeed a problem. Bottom line: I have no idea if it makes any economic sense, but I'm not willing to rule it out without analysis. --Steve Bellovin, http://www.cs.columbia.edu/~smb
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