Microsoft's Black Tuesday bandwidth impact?

Frank Bulk frnkblk at iname.com
Wed Jan 9 21:38:35 UTC 2008


Adam:

Thanks for that detailed explanation.  I was under the assumption the MSFT
released updates just hours before 3 am (which is also a staggered target
across the time zones).  

With almost a day of lead time (plus computers turned off, Automatic Updates
turned off, local SUS servers), the network impact would be minimal, and
with day-to-day traffic as varied as it is, probably imperceptible if I
compared it to Tuesdays the week before or after.

Frank

-----Original Message-----
From: Stasiniewicz, Adam [mailto:stasinia at msoe.edu] 
Sent: Wednesday, January 09, 2008 3:22 PM
To: frnkblk at iname.com; nanog at nanog.org
Subject: RE: Microsoft's Black Tuesday bandwidth impact?

I think you misunderstand how Automatic Updates work.  The "3 AM" default
setting simply defines when Windows will install updates.  The actual
detection and download of updates (including the file that the scan engine
uses) are not done at 3 AM.

Using default settings, Windows will run an update check every 22-17.6
hours.  The 20% variance is to help prevent floods from computers booted up
at the same (for example, a computer lab).  This process will: check to see
if there is a new update detection file, download an updated list, run a
scan to see if the computer needs updates, and download needed updates.  

Microsoft releases updates on Tuesday at 10:00 AM PST (though some months
they have been a few hours late).  So to monitor the impact of the updates,
look at the traffic between Tuesday 10:00 AM PST through Wednesday 8:00 AM
PST.  Note, not all computers will get their updates at this time.  The most
simplest example are computers that are off.  But also, many people
disable/modify their Automatic Updates settings, while others will use the
Windows Update site.

Hope that helps,
Adam Stasiniewicz

-----Original Message-----
From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu] On Behalf Of
Frank Bulk
Sent: Wednesday, January 09, 2008 2:48 PM
To: nanog at nanog.org
Subject: Microsoft's Black Tuesday bandwidth impact?


Every month I look at my upstream bandwidth graphs and I see no blip in the
hours before 3 am on Microsoft's Black Tuesday.  I would think that with the
thousands of PCs out on our network downloading updates around that time
that I would see *something*.  I know every Black Tuesday I see my three
PC's blinking a logon screen.

Are MSFT's monthly updates really a non-event in regards to internet
bandwidth?

Frank




More information about the NANOG mailing list