[e2e] a means to an end
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
>>>> Maybe this explains why so many seem to confuse the hardware and
>>>> with networking. KInd of like confusing the Intel instruction set
>>>> 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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