number of hops != performance

Mikael Abrahamsson swmike at
Tue Nov 5 22:25:10 UTC 2002

On Tue, 5 Nov 2002, Petri Helenius wrote:

> If your L3 topology is well aligned with your L1 topology, you usually
> end up with more hops. The less intermediate gear, like SONET you
> use but do L3 instead, the more L3 hops you have.

This is exactly what we do, we run L3 pretty much directly on the fiber 
with some OEO-repeaters in between, therefore we display much of our 
infrastructure in a traceroute. We can do a L2 hop instead, that will 
probably make things less efficient in some cases and will hide the 
underlying infrastructure, but will make customers happy. I don't like to 
do silly technical suboptimisations for cosmetical reasons.

> > B) you have more places for things to go wrong in both hardware and
> >    software.
> This is specifically true for the hop-hiders using MPLS or other mostly
> pointless multihop recursive switching systems.

Quite true. I mean, either the equipment does an L2 or an L3 hop, either 
way it can go wrong.

Mikael Abrahamsson    email: swmike at

More information about the NANOG mailing list