On Wed, Aug 28, 2013 at 09:54:28AM -0700, Michael Smith wrote:
It's really "can reach" versus "how well can they reach." I can't any provider that would have less than a full view of the DFZ but, if your primary traffic is to Provider X, and one of your Tier 1's peers locally and the other peers in France, then you would look more closely at the closer one. Unless, of course, that local peer was saturated 99% of the time. Then France might be attractive.
One thing to keep in mind is that for major Tier 1s, it's not at all uncommon to see some very large percentages of traffic (like say well north of 50%) stay completely on-net, going from customer to customer. In this type of model, capacity to other third party peers (typically the other Tier 1's) becomes secondary to other considerations like backbone capacity, which is why those "huge Tier 1 networks" often have much less peering capacity than you might otherwise expect. Tier 2's on the other hand, typically spend the vast majority of their time/money/effort figuring out how they can deliver traffic to "other networks" via peering and transit relationships. This usually means they have much smaller amounts of backbone capacity, but relative to their total sizes they often have a lot more capacity to the other major peering/transit networks. The economics of each model are vastly different too. Tier 2's are typically always looking to take advantage of tricks like hot potato routing and 95th percentile billing to get "free" inbound to minimize their backhaul costs. All too often people tend to get caught in the mentral trap of thinking "peering == free", but in reality the Tier 1's are just shifting the majority of their operational costs into backbone instead, and peering becomes the way to handle the "leftovers". Each model has its advantages and weaknesses, but most people who haven't lived in both worlds tend to vastly underestimate the realities of the "other side"'s cost models. There is a lot to be said for the value of a Tier 2 network. Sometimes throwing a token amount of money at a problem solves it much more effectively than waiting for two squabbling Tier 1's to fight over the "principal" of not paying anything or risking being perceived as weak. And a Tier 2 with multiple transit paths and extensive peering options may be able to easily reroute traffic around a particular problem spot in a way that a Tier 1 just doesn't have the ability to do. Then again, sometimes there is value in just buying transit from someone who operates a massive entwork, with the economy of scale necessary to implement terabits of backbone capacity for cheap, and a huge customer base. As for the "which one should I buy" question, a smart person would realize the different strengths and weaknesses of each model, and probably end up buying from (at least) one of each to take advantage of this. Of course in reality 99% of people fail to understand any of this, and turn off their brains after thinking things like "1 > 2 so it must be better". :) -- Richard A Steenbergen <ras@e-gerbil.net> http://www.e-gerbil.net/ras GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)