MTU to CDN's

Fri Jan 19 06:46:29 UTC 2018

I don't mind letting the client premises routers break down 9000 byte
packets. My ISP controls end to end connectivity. 80% of people even let
our techs change settings on their computer, this would allow me to give
~5% increase in speeds, and less network congestion for end users for a one
time $60 service many people would want. It's also where the internet
should be heading... Not to beat a dead horse(re:ipv6 ) but why hasn't the
entire internet just moved to 9000(or 9600 L2) byte MTU? It was created for
the jump to gigabit... That's 4 orders of magnitude ago. The internet
backbone shouldn't be shuffling around 1500byte packets at 1tbps. That
means if you want to layer 3 that data, you need a router capable of more
than half a billion packets/s forwarding capacity. On the other hand, with
even just a 9000 byte MTU, TCP/IP overhead is reduced 6 fold, and
forwarding capacity needs just 100 or so mpps capacity. Routers that
forward at that rate are found for less than $2k.

On 18 January 2018 at 23:31, Vincent Bernat <bernat at luffy.cx> wrote:

>  ❦ 18 janvier 2018 22:06 -0700, Michael Crapse <michael at wi-fiber.io> :
>
> > Why though? If i could get the major CDNs all inside my network willing
> to
> > run 9000 byte packets, My routers just got that much cheaper and less
> > loaded. The Routing capacity of x86 is hindered only by forwarding
> > capacity(PPS), not data line rate.
>
> Unless your clients use a 9000-byte MTU, you won't see a difference but
> you'll have to deal with broken PMTUD (or have your routers fragment).
> --
> Many a writer seems to think he is never profound except when he can't
> understand his own meaning.
>                 -- George D. Prentice
>