Hi Mike,
On Fri, 30 Jan 2004 09:09:57 -0800 (PST)
Michael Thomas <mat(_at_)cisco(_dot_)com> wrote:
Now wait a minute. It's your bandwidth... shouldn't
you be _shaping_ his traffic if there's some reason
he shouldn't be using one path or another? And thus
provide negative feedback so that he has incentive
to use the path that you want him to use? After all,
the end consumer is likely clueless about your
network and is going to do whatever they can to
get what they're after -- bandwidth. Sounds to
me that if he's able to cause your bills go
through the ceiling _you're_ doing something
wrong.
I guess Daniel's problem is not that simply solved.
Just the shaping isn't enough, because the backup path should
be fully used only when the main path has some "trouble".
Moreover, "trouble" isn't also such a simple thing like
a direct link failure, such as fibre cut, but it includes
yet upper link(ISP)'s failure.
This is not even a problem of "OK" or "Not OK".
I mean, those cases are very likely to happen that you can
communicate with only a few of ASes through the main path.
So, though you may say "we can stop the shaping if we have
troubles in the main path," it is not such easy.
You have to change the bandwidth of backup path's shaping
depending on the number of routes passed from main path's
upstream ISP.
I'm not familiar with BGP routing techniques that much,
but I guess these policies can be implemented, right ?
Though I believe end-to-end multihoming is the way to go,
I don't have a good answer for this problem.
--
/arifumi
a(_at_)arifumi(_dot_)net