[Nsi-wg] Policy use cases

[Henrik Thostrup Jensen]

On Mon, 9 Mar 2015, Henrik Thostrup Jensen wrote:

> I am aware of the possibility of including source/destination STPs as 
> proposed elsewhere, but that is flawed too (but I will answer that in another 
> email replying to that slideset, as there are multiple issue with that).

I cannot find the suggestion for this, so I'll just add it here.

Adding source/destination STPs to the request was suggested (I think) as a 
way for UPAs to check if transit policy was kept. However:

1. I cannot actually convince my self it is enough. While it will 
certainly catch some cases that cannot be cought from looking at the 
cross-connect there might be some situations where it is not enough. I 
don't have a counter-example, but I haven't seen an argument for why it 
should be correct.

2. The data is informational only. I.e., all one have to abuse the system, 
is to craft a request with some other source/destination than what is 
planned. That is, the mechanism is practially trivial to bypass. It should 
be difficult - not easy - to abuse the system.


     Best regards, Henrik

  Henrik Thostrup Jensen <htj at nordu.net>
  Software Developer, NORDUnet