On Fri, Jul 19, 2002 at 02:11:29PM -0600, Me wrote:
I think you missed part of his comment: " of course there are always some "twinking" done regularly to give higher priorities to the higher bandwidth, link condition etc"
so fiber mileage is just the base, with modifications to make it work correctly, based on bandwidth, etc.
Yeah, my (limited) experience is the opposite. At the previous large operator at which I had enable, the IGP metrics were chosen primarily according to circuit size, and were subsequently tweaked for other issues (such as circuit latency, or the requirement to balance cross- US traffic across non-parallel circuits). In my experience, congestion is a much more effecive killer of service than latency due to optical distance. Hence attracting traffic to circuits where there is more likely to be headroom seems a more reasonable first-order approach for choosing metrics. That experience is all in networks where intra-AS traffic engineering was done at the IP layer, however; in networks where there is a lower layer of soft traffic engineering maybe other approaches would be more appropriate. Joe