Use of Default in the DFZ: banned in philly, see it now on the net!

Wed Jun 24 20:29:16 UTC 2009

Hi,
The classification we have is one possible classification, it's hard  
(if not impossible) to capture the diversity of the network in 4  
classes without having mislabels. We noticed that there were a  
considerable number of networks with special arrangements (i.e. a very  
small number of local downstreams mostly non-profit), specially in  
academic campus networks. Because these networks are not ISPs in the  
traditional sense (not their main business), we relaxed the stub  
threshold  at the cost of including some other cases of networks that  
are actual ISPs (e.g. Jack Bates).  Looking forward to see Randy's  
survey results to see how often this happened.

Thanks,

--Ricardo

On Jun 24, 2009, at 12:26 PM, Pete Templin wrote:

> Lixia Zhang wrote:
>> On Jun 24, 2009, at 11:04 AM, Pete Templin wrote:
>>> In (your) theory, your paper may hold up.  In practice, your  
>>> definition of stub network is most likely considered wrong, and  
>>> that likely shifts a lot of the assumptions in your paper.
>> But I also believe that there are a few common practical patterns  
>> that cover majority of reality.
>> We need to be mindful of diversity in real world but also capture  
>> basic common patterns (I'd agree that the paper perhaps should have  
>> said a few more words about the former).
>
> Skimming the paper turns up a key sentence, "Stub networks, on the  
> other hand, do not forward packets for other networks."  What part  
> of that led you to think that stub networks forward packets for 1-4  
> downstream ASNs?
>
> pt