Evaluating Tier 1 Internet providers

Luke S. Crawford lsc at prgmr.com
Fri Aug 30 03:25:41 UTC 2013


On 08/29/2013 07:43 PM, Blake Dunlap wrote:
> +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.

...

>> 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.


a major problem here is that some providers try too hard to be tier 1... 
  -  my pager has gone off many times because $lowcost_tier1 decided to 
route a packet from them in san jose destined for them in Sacramento 
through texas.   Problem is, often that is still fewer hops, (even if 
it's many more ms) than going through my tier2 provider, so having the 
backup did not help me.  Nor would taking customer-only routes from 
$lowcost_tier1... the shortest path, in terms of hops, was through them, 
through texas.   There was nothing to be done short of switching to my 
tier2.

I have no idea how to solve this sort of problem automatically. 
Ideally, if someone has a congested or down link, I'd prefer that they 
not announce routes to that part of the internet, as I do have a backup, 
but that isn't how it works.



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