RE: LSRR traceroute packet acceptability

Kenichi Ishikawa (ishi@cs.washington.edu)
Tue, 22 Sep 1998 14:07:45 -0700 (PDT)

I was not aware of the difference of behavior between normal and
LSR packet.
Thank you for pointing out that.

Hmm... I'm also confused.

--
Kenichi Ishikawa


On Tue, 22 Sep 1998, Stefan Savage wrote:


> I'm confused about exactly how we hope to use LSR for measurements.  The
> classic problem with LSR is that intermediate routers do not process
> them on the "fast path".  They are not routed on the line cards but are
> frequently shunted to a much slower host processor.  Consequently, these
> packets will traverse the network slower than regular packets and are
> more likely to be dropped.  
> 
> Its seems like LSR paths can be used as a lower bound when compared with
> normal paths (ie a lsr path will only be slower and lossier than a
> normal path).  However, I'm not sure how reasonable it would be to
> compare metrics for two lsr paths (since the metrics will differ due to
> router architecture, load on the host cpu, etc...).  Am I
> misunderstanding the experiment?
> 
> - Stefan