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Re: Resilience: faults, causes, statistics, open issues
- From: David Andersen
- Date: Thu Jan 27 11:38:58 2005
On Jan 27, 2005, at 6:39 AM, András Császár (IJ/ETH) wrote:
This is self-serving, but see the intro and related work sections of my
thesis (we'll have a conference paper version of it done soon for NSDI,
but we're still revising it. Apologies for not having a shorter
reference to give you):
I've begun research on (carrier-grade, aka telecom-grade) resiliency
in IP transport networks. The first step would be to collect possible
failure events, their causes and consequences, statistics about
downtimes (mean time to repair) and mean times between failures, and I
would like to identify which of the problems are most typical (HW bug,
SW bug, cable cut through, plugged out (link going down), severe
I think this is the perfect forum to get some feedback from real
Is anyone out there who has some statistics/documents that would help
me in any way?
It doesn't focus specifically on carrier failures, but it has a batch
of references that might get you started on what the academic side
knows. I've also got some refs in there to some of the earlier teleco
studies, which I recommend taking a peek at. Again, relation to year
2005 ISP failures isn't totally clear, but it's a starting point.
Unfortunately, the reality is that we don't actually know all that much
as far as what's _really_ happening! Nick Feamster and I took a look
at some of the BGP routing failures (but didn't get back to root
Nick's also done some work on configuration management and building a
better routing protocol that's somewhat related to your question.
Ratul Mahajan examined BGP configuration errors - but it's not clear
exactly what fraction of failures or downtime are really due to those
David Oppenheimer studied failures at a few edge companies (app.
service providers, hosting providers, etc.). Has a nice breakdown of
failure causes and durations, but it's not clear if those numbers
directly translate to the carrier realm:
Finally, google back for some of Sean Donelan's NANOG posts. You'll
get some good individual cases from those, though the last time I
looked, I didn't find a big overall analysis.
Also, do you have any suggestions on open research issues to be solved
in the area?
Most of it. :) I (and probably others on this lis) would be
interested in what you find.