nanog mailing list archives

Re: Digital Island sponsors DoS attempt?


From: Dave Siegel <dave () siegelie com>
Date: Fri, 26 Oct 2001 08:58:41 -0700


I certainly wouldn't dispute DI's right to measure performance to
other places on the Internet.  After all, ICMP is an application too,
and as long as it doesn't negatively impact performance, there shouldn't
be anything wrong with it.

However, I would think it common courtesy to contact the network 
administrator of a site you intend to measure, particularly if your 
measurement tools are likely to trip security alarms.

On Thu, Oct 25, 2001 at 10:19:10PM -0500, Alan Hannan reportedly typed:


  Hi Brian,

  I know that an ISP can learn infornation about path quality off of
  its network.  I also know that many ISPs have no interest in
  learning about quality off of their network.

  You are right that discretely mapping empirical behaviour to datum
  such as AS Path, external_peering_link, and other various variables
  like Time of Day, etc... is difficult.  

  Some folks have made progress on this, and use it to make things
  better, some in a manual fashion, some in a more and more automated
  fashion.

  Some people would suggest to solve off-net quality problems by a/
  blaming, or b/ suggesting that the other network increase bandwidth,
  or c/ rerouting.  In order to do c/ sometimes it is helpful to learn
  information about different paths, from different vantage points.

  So, I don't really want to delve too deep into the theory of what
  exactly DI is doing, I suspect they'll tell us if they are as clever
  as they seem to be.

  I do know, however, that the gaining information about external
  performance can be useful for optimizing egress traffic flows, both
  on a micro, mid, and macro basis.

  With regards to your suggestion below about standardization, I think
  it would be great if stuff like IPPM, IPDR and such were done in the realm
  of off-net performance.  However, let's not confuse operational
  implementations (for example, off-net brains thinking about what to
  do) with standardized protocols required for interacting with
  others.  Egress flow optimization can be done autonomous of
  standards, and is, today :-)

  -alan

Thus spake Brian Wallingford (brian () meganet net)
 on or about Thu, Oct 25, 2001 at 11:41:20PM -0400:
On Thu, 25 Oct 2001, Alan Hannan wrote:

:
:  I suspect that DI, like many other companies, is actively monitoring
:  external sites to track, study, and hopefully improve connectivity
:  quality to them.

So, you suspect that Digisle has come up with a scheme for jiving
latency/path efficiency with as-paths, and integrating that into their own
routing policies?  Noone has done this well yet.  Those who have tried
have failed to realize the need for standardization, or have decided to
ignore such in the interest of developing a patented, proprietary scheme
(which is, based solely on common sense, doomed).

Conclusion: Digisle's probes are not at all justified.  Hopefully, they're
listening.

Admittedly, I may be misreading your theory.  If so, please elaborate.

cheers,
brian

-- 
Dave Siegel
HOME   520-877-2593   dave at siegelie dot com
WORK   520-877-2628   dsiegel at gblx dot net
                      Director, IP Engineering, Global Crossing


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