On Sun, 23 Sep 2007 michael.dillon@bt.com wrote: > > having full routes from multiple providers was the only way > > to be automatically protected. > > Not so. Anyone who had sufficient transit was also protected from > the games. And they shielded their customers as well.
Michael, how are these two statements not in agreement? It looks to me like you're saying the same thing: A network which claims "tier 1" status by failing to buy any transit, subjects its customers to connectivity failures when depeering happens, while a normal multi-homed network does not inflict that failure upon its customers. Isn't that what you're both saying?
I suppose that if you dig deeper, which most people don't seem to do, then buying transit is just one form of having full routes from multiple providers. But on the surface, the comment that I responded to seemed to be repeating that commonly held belief than only transit-free, default-free providers with multiple peers for any given prefix, can be considered Tier 1. Last century, there was lots of boasting in the business and people needed rules of thumb such as "default free" and "transit free" to sift the wheat from the chaff. But I don't think that is true anymore, especially not on a global scale (even a partly global scale). There are providers who provide high levels of service and reliability who have some transit and some default routes in the mix. I'd like to see a lot more focus on how a network deals with single points of failure, physical separacy of links, and the like. These are more important than whether they are a pure-play peering network.
Disclaimer: this is my first posting of the morning, thus it's inevitably dunderheaded or offensive, for which everyone has my apologies in advance.
Not at all. It is inevitable to have misunderstandings when going through a paradigm change. We went through the last one when the telecom industry bought up the ISP industry. But now we are going through another one as businesses higher up the OSI stack, like Google, are getting into running an IP WAN. Also, traditional telecom companies are diversifying into other service areas higher up the stack in a similar way to how IBM branched out from being a computer hardware manufacturer into a services company. --Michael Dillon