North American Network Operators Group
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Re: Outbound Route Optimization

  • From: Patrick W.Gilmore
  • Date: Thu Jan 22 04:49:25 2004 
On Jan 21, 2004, at 4:20 PM, vijay gill wrote:

On Wed, Jan 21, 2004 at 09:05:46PM +0000, Paul Vixie wrote:



            My questions are these:

"Is sub-optimal routing caused by BGP so pervasive it needs to be
addressed?"



that depends on your isp, and whether their routing policies (openness
or closedness of peering, shortest vs. longest exit, respect for MEDs)
are a good match for their technology/tools, skills/experience, and
resources/headroom.



In practice, all of the above just turn out to be marketing sauce
or in some cases, outright lies.

There is no substitute for dollar spend (opex and capex) to make
a network perform.  There is no magic sauce, there is no silver
bullet. You have adequate resources, you will have adequate
performance.




I dunno if the last sentence is a type-o or not, but it is definitely
incorrect in at least some cases. Having "adequate resources" in no
way guarantees "adequate performance". (Unless you define "resources"
to include the political clout to override business decisions which
help the bottom line but hurt performance - e.g. not peering with a
network because they are too small.)



OTOH, having inadequate resources does give you a near perfect chance
of having inadequate performance.






(experience says they're not going to trust your MEDs even if they're
close

enough to hear them.)


Most people don't trust MEDs for a reason paul, and it is not because
they want to mess with your customers.




There are a variety of reasons for not listening to MEDs, including
political reasons which may not be in the best interest of performance,
or even may be detrimental to performance.



I've found most people willing to put in the time & effort to give you
MEDs will give reasonably good MEDs. It also seems the hight of hubris
to assume you know what is happening inside someone else's network
better than the people who run that network. At least IMHO....





In any case, no matter how many resources or black boxes you have, you
cannot guarantee good performance on the 'Net. Too many people
involved over which you have no control. Even if you had control, BGP
is not the right tool to exert such control in all cases.



--

TTFN,

patrick