Re: [sidr] Burstiness of BGP updates (was: WGLC: draft-ietf-sidr-bgpsec-reqs)

[Jakob Heitz <[e-mail]>]

I can not believe that it will be 2X.

First case: A beacon will very rarely cause a different
bestpath.

Second case: There is actually a changed route being updated.
You will receive both a regular update and a signature.
Only one of those will casue a new bestpath in the great
majority of cases.

Basically, in the large majority of cases, a signature does not
change the bestpath.

--
Jakob Heitz.

> -----Original Message-----
> From: George, Wes [mailto:[e-mail]]
> Sent: Monday, November 14, 2011 5:37 PM
> To: Jakob Heitz; Randy Bush
> Cc: Sriram, Kotikalapudi; sidr wg list
> Subject: RE: [sidr] Burstiness of BGP updates (was: WGLC: draft-
> ietf-sidr-bgpsec-reqs)
> 
> > From: [e-mail] [mailto:[e-mail]] On
> Behalf
> > Of Jakob Heitz
> >
> > The difference is that today's updates all have the same urgency.
> > BGPSEC is not urgent. It doesn't matter if you don't receive a
> > signature for a few minutes.
> > An UNREACH is not signed.
> 
> [WEG] I don't totally agree with this characterization. If the
> BGPSec info triggers a recalculation of bestpath from what was
> chosen when the unsigned update came through, this has the potential
> to drive 2x the work, essentially take 2x longer for convergence,
> plus push another round of updates to downstream neighbors, another
> reprogram of the FIB, etc. Seems to me by the time we've gained any
> benefit of saving updates for later because the box is busy, we've
> triggered a far worse potential death spiral on a busy box.
> Processing a few additional updates is rather pale in comparison to
> having to consistently recalculate a non-trivial percentage of the
> table when the box gets "busy."
> Similar to buffering and QoS, you can't get something for nothing
> here, and there are limits to where deferred processing can help to
> smooth out peaks vs. simply throwing more capacity at the problem,
> especially in the land of often underutilized multi-core systems.
> 
> Wes George
> 
> This E-mail and any of its attachments may contain Time Warner Cable
> proprietary information, which is privileged, confidential, or
> subject to copyright belonging to Time Warner Cable. This E-mail is
> intended solely for the use of the individual or entity to which it
> is addressed. If you are not the intended recipient of this E-mail,
> you are hereby notified that any dissemination, distribution,
> copying, or action taken in relation to the contents of and
> attachments to this E-mail is strictly prohibited and may be
> unlawful. If you have received this E-mail in error, please notify
> the sender immediately and permanently delete the original and any
> copy of this E-mail and any printout.