+10 Good explanation. This is a lot of why I have someone like Cogent/L3/etc and some random transit provider in most of my pops I spec, plus a backhaul to another node.
On Thu, Aug 29, 2013 at 9:37 PM, Richard A Steenbergen <r...@e-gerbil.net>wrote: > 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 <r...@e-gerbil.net> http://www.e-gerbil.net/ras > GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC) > >