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Re: [RRG] Are host-stack modifications allowed or disallowed ?

William Herrin wrote:

On Wed, Mar 5, 2008 at 8:07 PM, Tony Li <tony.li@tony.li> wrote:

 |>  [...] Why now?  What's changed?
 |BGP communities

 That's part of the existing architecture, not anything new.


Tony,

Back in '98 I don't recall my upstreams providing a list of
communities I could assign to my announced routes which would alter
the way in which they advertised them to their upstreams and peers.
It might not have been common, but was definitely available among several of the big players in 1998. 
For sure UUnet, Teleglobe, and two or three others (MCI? AboveNet? ebone?).
More than one of those listed the communities in their RADB entries.


That offering seems somewhat common today.



 |CDNs (e.g. Akamai)

 Interesting, but I'm missing on how that's relevant.


At least one of us is being obtuse. I won't claim it isn't me.

Paraphrasing your question, you asked: What has changed since we
allowed loose source routing to slip away that should cause us now to
be concerned about giving the customer finer grained control over
routing.

The answer is: our customers now pay large amounts of money for
relatively crappy methods of moving packets to their customers in a
"better" way than central servers with generic BGP could. Back when we
allowed loose source routing to die, nobody was spending money on such
a thing.
Probably because LSRR as a "traffic engineering" solution didn't (and doesn't) scale, especially from a hardware perspective.
Crappy often scales well. "Never underestimate the bandwidth of a station wagon full of mag tapes." (Dates back to uucp days.) 

Brian Dickson

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