The MPLS WG Archive

["David Allan" <dallan@nortelnetworks.com>]

Title: RE: Load balancing draft

Tom:

Not entirely true, any point where there is useful predictability reduces the number of possible faults that may only be caught by random process. IMHO that is useful.

cheers
Dave

> -----Original Message-----
> From: Thomas D. Nadeau [mailto:tnadeau@cisco.com]
> Sent: Thursday, November 21, 2002 10:59 AM
> To: Fedyk, Don [BL60:1A00:EXCH]
> Cc: George Swallow; Fedyk, Don [BL60:1A00:EXCH]; Allan, David
> [CAR:NS00:EXCH]; Alia Atlas; Shahram Davari; 'MPLS@UU.net'
> Subject: Re: Load balancing draft
>
>
>
> >George
> >
> >Let me restate. You Said "All load balancing done in
> prescribed manner."
> >Which is certainly restrictive. The Draft for load balancing
> says  not to
> >use certain fields. That is not the same. So I added different
> >implementations for load balancing following the draft still
> have freedoms
> >and different vendors can choose different algorithms.
>
>          Not really. If you want things to work the way the
> draft aspires
> them to, then everyone in the MPLS domain must use the same,
> predictable load balancing algorithm.  Going halfway doesn't work,
> and is arguably no better than what we have today.
>
>          --Tom
>
>
> >Hope that makes it clear,
> >Don .
> >George Swallow wrote:
> >
> >>Don -
> >>
> >>This seems to a non-sequitor.  I don't see how this comment
> relates to
> >>what I wrote below.  Were you trying to answer some other message?
> >>
> >>...George
> >>
> >>
> >>
> >>>George to be fair I heard Dave say  that the load
> balancing should not
> >>>use certain fields which are part of the label stack. This
> does not
> >>>require that balancing be done in a prescribed manner,
> freedom is still
> >>>there. Instead load balancing should be correct with
> respect to all of
> >>>MPLS formats  including reserved labels.
> >>>
> >>>Don
> >>>
> >>>George Swallow wrote:
> >>>
> >>>
> >>>
> >>>>>If you look at my post from rather late last night, I'd
> question the
> >>>>>lighter
> >>>>>overhead assertion. This discussion is really orthogonal
> to the probe
> >>>>>frequency and is more concerned with the probe
> quantity/quality to
> >>>>>determine
> >>>>>there is a problem. Goodness and scalability (and again
> my favorite
> >>>>>"bounded
> >>>>>detection time") can be expressed as how authoritative a
> test result is in
> >>>>>proportion to the messages expended. Also the fewer
> heuristics required to
> >>>>>interpret the test results, the more reliable the
> overall system is....
> >>>>>
> >>>>>
> >>>>My only point is that if your measurement is based on the
> assumption
> >>>>that all load-balancing is being done in a prescribed
> manner, then the
> >>>>quality of that measurement is very much dependent on the
> certainty
> >>>>that all of the nodes in the path are actually behaving
> according to
> >>>>that assumption.  On node behaving differently could
> reroute a large
> >>>>portion (or all) of the probes.  Thus the measurement could be far
> >>>>
> >>>>
> >>>>from the actual behavior.
> >>>
> >>
> >>==================================================================
> >>George Swallow       Cisco Systems                  (978) 497-8143
> >>                     250 Apollo Drive
> >>                     Chelmsford, Ma 01824
> >>
> >>
> >
>
> Success is relative; the more success, the more relatives. -Anonymous
>
>
>