Re: Is anyone actually USING IP QoS?
Vijay Gill <wrath@cs.umbc.edu> 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 :) --vadim
On Tue, 15 Jun 1999, Vadim Antonov wrote:
Vijay Gill <wrath@cs.umbc.edu> wrote:
I guess it's my private rule-of-thumb. (Antique Kleinrock and Klein, maybe?)
The paper titled "Stochastic Performance Evaluation of Hierarchical Routing for Large Network" by Kamoun and Kleinrock does give a result for optimal levels of hierarchy to be ln(n), where n is the number of nodes, in a symmetric distributed network, for routing purposes.
that the only reference to the name "Avici" i was able to find is the particularly hot kind of hell in Buddhist mythology :)
This has amused me for months. The Thus Come One of Pervasive Lights and Proper Views told her, "You are supposed to fall down into The Avici Hell because of your evil karma, and experience the acute suffering without any respite. In the cold Hell, the offenders will encounter the severely cold wind and be tortured by the sudden chill. In the feverish Hell of heat, the offenders will experience sudden heat waves, which are brought about by the hot wind." /vijay
participants (2)
-
Vadim Antonov
-
Vijay Gill