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Re: shim6 @ NANOG (forwarded note from John Payne)
On 24-feb-2006, at 12:26, Mikael Abrahamsson wrote:
1) Traffic engineering, traffic engineering and traffic engineering
I guess we'll have to take this one to heart. I believe this means
decent traffic engineering must be in the first version of the specs.
I think it should be considered whose problem shim6 is aimed at
solving and whose side shim6 development should be one. ISPs want
to do TE, customers want to work around it (perhaps).
In my book, TE is evil and ISPs should be lossless and efficient.
TE is just evil patching.
In my book, traffic engineering is chapter 6. :-)
You can read it online: http://www.oreilly.com/catalog/bgp/chapter/
ch06.html
If you have several links to the internet, you don't want one to sit
idle while another is congested. So traffic engineering is an
essential part of multihoming. Now obviously most ISPs are multihomed
themselves so they want to do their own TE. That's completely
legitimate. However, that doesn't mean that they get to decide how
their customers can do TE. If a customer sends traffic to an ISP and
that traffic conforms to SLAs and accepted congestion control
methods, the ISP should deliver the packets. That's their business.
But some people at the NANOG BOF expressed a different view: "the law
of large numbers only works if I control the large numbers". And:
"most small businesses can't single home properly". To which a
certain ex area director replied: "that doesn't stop them from doing
it twice.
[...] just like us they're all idiots".
Unfortunately, these days, many people take TE to mean "break up my
portable address block in small parts". That is one way to do it, and
an effective one, but also the least scalable one.
I like the fact that shim6 discourages end users from getting their
own address space and AS number just because of redundancy and
multihoming, and I definately like the fact that I will be able to
move between IPs due to mobility, and keep my ssh session up during
this move. I really hate shutting down my ssh sessions just because
I go from wireless to wired mode. Without "screen" I would hate it
even more.
Well, shim6 isn't really mobility, although you could probably do
this with it.
This has to take precedence over some ISPs desire to do TE. Perhaps
if their routers could be smaller and simpler due to smaller TCAM
space need, they could afford to upgrade their links instead of
doing a lot of TE to work around the bw problem. Their job is to
move the packets the customer sends to them, and shim6 is an
enduser feature and they shouldn't bother about it.
Amen to that.
And I hope they're not using TCAMs for the (entire) IP routing table,
because these suckers use lots of power and scale linearly.