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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: IGP metrics on WAN links
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
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