NTAC Peering Working Group

[Michael H Lambert <>]

Steven,

On 30 May 2013, at 10:52, Steven Wallace wrote:

> I think you've hit on something that's going to require network engineers 
> to re-think certain approaches to troubleshooting. IMO, the idea of an 
> in-band probe to determine the path is simply not going to be a part of the 
> SDN future (I could be wrong, but that's my prediction). The good news is 
> that you no longer need it. What I mean is that the controller knows the 
> entire path. I would be asking for an app where the engineer can easily  
> say to AL2S "what's the path for this flow" and the app responds with the 
> complete path as it exists in realtime.

If there are multiple controllers, do they all contain the entire state or 
are they just "cooperative"?  I'm trying not to think about the old mbone 
traceroute that would do a hop-by-hop query.

Michael