The MPLS WG Archive

[George Swallow <swallow@cisco.com>]

> 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

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George Swallow       Cisco Systems                  (978) 497-8143
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                     Chelmsford, Ma 01824