[e2e] a means to an end

Jon Crowcroft Jon.Crowcroft at cl.cam.ac.uk
Mon Nov 10 15:36:51 PST 2008

mpls on ethernet is fine if you do cells in frames

but remember, mpls is not a good solutuon for
mobility, or multicast

nor was atm

we tried - it failed.
In missive <4918A1B4.8010205 at telemuse.net>, Lynne Jolitz typed:

 >>I assume by Fred's "MPLS on Ethernet" mention that the reason underlying 
 >>their unusual approach is that they see no point (except more overhead) 
 >>in the additional layers below an MPLS routing layer, so the end-points 
 >>are the only things that matter (while ignoring of course, diagnostics, 
 >>blockage identification and so forth).
 >>But let's take this further. An old suggestion proposed at an IETF in 
 >>the early 1980's was similarly to disconnect the appearance of the 
 >>routing layer and visibility of the network itself and tunnel everything 
 >>on top of the network, so you'd have a layer 3 network encapsulated on 
 >>top of a layer-3 network not visible except within the routing cloud. 
 >>This was to hide the actual infrastructure so it couldn't be attacked. 
 >>One could even encapsulate with TCP instead of IP such that you could 
 >>allocate bandwidth portions and routes in an independent way - more like 
 >>an OC IS-to-IS routing scheme. The view was the only people who cared 
 >>about routing were the ones who could see how it was working, so why be 
 >>open to DDOS attacks on the routers themselves, and also so as to 
 >>promote quality. This was before BGP.
 >>So now we've got a Chinese proposal on MPLS-on-Ethernet. The advantage 
 >>of their approach is that at layer 2 you can do it with mindless 
 >>switches and spanning tree algorithms. This means very efficient, very 
 >>low power, very dumb routers. Can this be produced? Yes, in massive 
 >>quantities. Would people buy this? Very likely if cheap enough.
 >>How would massive deployment impact the Internet? That's one I'm 
 >>wondering about. Lynne Jolitz.
 >>Fred Baker wrote:
 >>> On Nov 9, 2008, at 11:05 AM, David P. Reed wrote:
 >>>> I'm completely confused by the suggestions from Fred and Noel that
 >>>> 802.11 802.1, MPLS are somehow competing with the current IP routing
 >>>> system.  None of those are end-to-end solutions, ...
 >>> Depends on your viewpoint. There are those that think of them as end  
 >>> to end solutions in some stated domain. In Beijing during the last  
 >>> week of October I visited a school that literally was proposing MPLS- 
 >>> on-Ethernet as an end-to-end solution.
 >>> The reason I mentioned them is this. You noted that the Internet was  
 >>> designed as a network of networks, and IP was the ring to bind them.  
 >>> True enough. We have two variations on that in the present Internet.  
 >>> One is that we literally have separate networks connected through a  
 >>> collection of backbone networks, often by means of network address  
 >>> translators or other gateways. The other is that the IP protocol  
 >>> usually runs atop some lower layer (what I call "intranet", what  
 >>> others inexplicably call "layer 2") networks, including various  
 >>> extended LAN, circuit switch, and virtual circuit networks.
 >>> To my way of thinking, whether you mean this in an infrastructure  
 >>> sense, and administrative sense, or a routing protocol sense, the  
 >>> Internet is very much a network of networks.
 >>>> Is the confusion between the limited scope of 802.11 and 802.16 and  the
 >>>> planet-scale scope of IP addressing really prevalent among the  
 >>>> community?
 >>>> Maybe this explains why so many seem to confuse the hardware and  
 >>>> cabling
 >>>> with networking.   KInd of like confusing the Intel instruction set  
 >>>> with
 >>>> the Win32 API, or confusing the workings of the marketplace with the
 >>>> resolution of social issues.
 >>>> Fred Baker wrote:
 >>>>> On Nov 9, 2008, at 4:31 AM, David P. Reed wrote:
 >>>>>> why not multiple competing "routing" layers?
 >>>>> We have those, in spades. Consider 802.11, 802.1, 802.16, ATM and  
 >>>>> its predecessors, etc.



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