On Sun, 30 Aug 2009, William Herrin wrote:
If your 95th percentile utilization is at 80% capacity, it's time to start planning the upgrade. If your 95th percentile utilization is at 95% it's time to finish the upgrade.
I now see why people at the IETF spoke in a way that "core network congestion" was something natural.
If your MRTG graph is showing 95% load in 5 minute average, you're most likely congesting/buffering at some time during that 5 minute interval. If this is acceptable or not in your network (it's not in mine) that's up to you.
Also, a gig link on a Cisco will do approx 93-94% of imix of a gig in the values presented via SNMP (around 930-940 megabit/s as seen in "show int") before it's full, because of IFG, ethernet header overhead etc.
So personally, I consider a gig link "in desperate need of upgrade" when it's showing around 850-880 megs of traffic in mrtg.
-- Mikael Abrahamsson email: swm...@swm.pp.se
