T1 vs. T2 [WAS: Apology: [Tier-2 reachability and multihoming]]

Sun Mar 27 16:29:53 UTC 2005

On Mar 26, 2005, at 11:21 PM, Randy Bush wrote:

>> forget this concept of tier1, 2, 3 .. they are little more than terms 
>> used
>> by salesmen.
>
> at least t1 and t2, also permeate academic papers where the real
> topology is actually measured.  but we should not let demonstrable
> measurements get in the way of our defense of the position of our
> smaller networks by marketing people.

And how, pray tell, does one actually "measure" T1 vs. T2 networks?  
(Assuming you are not talking about two of the Terminator movies. ;-)

If someone is paying Network A, but sends communities to be treated as 
a peer, are they T1 or T2?

If someone buys from Network B, but peers with all of Network B's 
peers, and therefore does not appear in a path through Network B in  
those peers' BGP tables (except at the actual peering router), are they 
T1 or T2?

If someone "peers" with Network C, but is out-of-balance and pays a 
settlement fee every month, are they T1 or T2?

Assume someone else is out-of-balance with Network C, but in the other 
direction, does that make Network C a T2?  Even if the network in 
question still pays Network C?

Etc., etc., etc.

There might be a way to define "Tier 1" and "Tier 2" sufficiently well 
as to disambiguate all the variations, but I do not think you could do 
it without seeing (NDA'ed) contracts and/or actual router 
configurations - neither of which are likely without the help of the 
network in question.  And if you have their help, you can just ask. :-)

Back on a more operational topic, it really doesn't matter what "tier" 
you are, it just matters how good your connectivity is.  There is no 
need to 'defend' the 'smaller networks'.  Some of the "tier 1" networks 
have totally suck ass connectivity.  (Yes, 'suck ass' is a technical 
term. =)

-- 
TTFN,
patrick