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Re: Is anyone actually USING IP QoS?

  • From: Vadim Antonov
  • Date: Tue Jun 15 16:54:16 1999

Vijay Gill <[email protected]> wrote:

>> Scalability on the Internet pretty much means that algorithms should run
>> in O(log(N)**M) where N is the total number of end-points and M is
>> constant.  (Note that non-CIDR unicast routing doesn't fit this
>> criterion, but CIDR does).

> Reference to this?

I guess it's my private rule-of-thumb.  (Antique Kleinrock and Klein, maybe?)

Anyway, O(N) seems to be infeasible (as at least some network components will
have to scale at super-Moore's law exponential rates), and O(log(N)) - too strict
(all dynamic routing algorithms are super-linear, but still work).

The design based on O(P(log(N))) algorithms was demonstrated to work in practice
(DV  of SPF with route aggregation).  O(P(N)) (non-hierarchial routing) was
demonstrated to fail during the CIDR deployment saga.

>The pressure is being applied now.  Vendors however had a lock on this
>market, witness how long it took for cisco to give oc-12 atm interfaces.
>They didn't move till uunet put the GRF into the core.

The pressure is called competition :)

Unfortunately, large switching equipment vendors still didn't get a clue on
how to build real fast routers.  (Nortel may be an exception, with their
stake in Avici; however i have serious misgivings about ability of Avici
design to deliver on promises.  Hypertorus is not what one wants to use
for general permutations.  And i find their claim to be inventors of massively
parallel routing simply hilarious.  Obviously, their marketing department
employs Al Gore as a PR consultant.  Never mind that the only reference to the
name "Avici" i was able to find is the particularly hot kind of hell in
Buddhist mythology :)