Le 22/08/2019 à 01:38, Fred Baker a écrit :
On Aug 21, 2019, at 12:56 PM, Masataka Ohta
<mohta@xxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
Once a full routing table is available on all the end systems, it
is easy for the end systems try all the destination addresses, from
the most and to the least favorable ones, based on the routing
metric.
Ohta-san:
I'm familiar with the paper "End to end arguments in system design"
as well. I'm also familiar with John Day, although I suspect I have
learned more from him than he has learned from me.
Interesting. In the same line, the Hourglass was recently covered by
July CACM. It questions the widely agreed validity of E2E Arguments in
explaining the Internet success.
For example, one of the points made is that "end-to-end arguments do not
necessarily lead to a spanning layer [IP, waist] that maximizes possible
supports [PHY, MAC]."
Alex
That said, we don't operate on the end2end principle in the Internet,
in the sense of the application determining the route its packets
will take to a destination. Applications know the addresses they
might send packets to, but they have no idea by what path said
packets might be routed - and probably wouldn't know how to interpret
them if they did. That is separately determined by every AS the
packet goes through, and can change in a clock tick. The network is
intelligent - it uses routing protocols scubas BGP, OSP, and IS-IS to
determine the routing of packets without the application being aware
or involved.
Yours very humbly, Fred
