Re: Traceroute versus other performance measurement

[Kai Schlichting <kai () pac-rim net>]

At Wednesday 01:54 PM 11/29/00, smd () clock org wrote:


> | At the expense of using all their bandwidth ttcp should provide some
> | reasonable measure of performance under those circumstances.
>
> ttcp has the disadvantage of invariant 5-tuple, which is germane to
> this problem.
>
>        Sean.

While this is moving rapidly towards a rather marginal topic, the
above struck me. And Google says for "tuple ttcp" :
http://www.cs.umn.edu/classes/Spring-1999/csci5212-nh/toc.html

Do I understand it correctly that the "invariant 5 tuple" refers to
5 non-variable aspects of this performance test, being namely:

- tcp or udp or icmp(?) protocol
- local IP address
- local protocol port or message type
- remote IP address
- remote port port or message type

E.g.: performance measurements will gravitate towards a result not
representative for the totality of all traffic, as the 5 variables
are rather fixed, or at the least fixed for the duration of the test ?

Has intelligent switching and forwarding (Layer-4 and up) started to
make such a significant impact on end-to-end performance that all
traditional performance tests must necessarily be flawed ?
(there must be a reason why my MRTG graphs of HTTP GET's to websites
 are so much more consistent than icmp pings...)



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