[Nsi-wg] Example routing policies in NSI

[Henrik Thostrup Jensen]

Hi

On Wed, 4 Feb 2015, John MacAuley wrote:

> Here is a slide package capturing my understanding of the routing 
> policies described in Uppsala.  Not sure if I missed any.

I just had a quick look at it, but from the top of my head:

Link preferral. Many networks are connected through multiple links, but 
can also send traffic over backbonetransit networks. And there can be more 
of these. Being able to priotize between these is pretty important.

There are no cases with selective transit (well, only trivial ones). For 
instance with something likes this:

A - B - C - D
       \ E

A can reach C & E, but not D.

Furthermore we are currently discussing this case with another 
network/community:

A - B - C - D

A should be able to reach B+D
B should be able reach all.
C should be able to reach B+C
D should be able to reach A+B+C.
(at least it is symmetric)

That is, A and C are not exchanging traffic, but C provides transit to D, 
and D has transit to A through B and C. Yay!

I'd like to stress that it is not NORDUnet bringing the insanity here, but 
a case of conflicting link AUPs and this issue: 
https://honestnetworker.wordpress.com/2013/06/28/5/

I'll take a closer look at this and the other slides next week.


     Best regards, Henrik

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