Re: [mpls] MPLS Network Actions Framework

[Tony Li <[e-mail]>]

Hi Robert,

> So I am not so much worried about control plane state - especially that distribution of those actions mappings could be as simple as configuration push or pub-sub model. If you think that control plane memory associated with keeping state of local actions would be an issue then we clearly would have a different opinion on this. 
> 
> But please observe that even if you carry action ID in a label stack you still need to have your hardware understand it (state) and execute such action (no difference). 
> 
> The only difference I could think of would be in parameters of actions. But looking at list of use cases I do not see that it contains such requirement to embed parameters of executed actions also in each packet. 
> 
> So in control plane assisted model those parameters would indeed occupy data plane memory while in packet embedded case (example when they are part of SRH) they would not. 


You seem to be under the impression that I’m arguing with you.  I’m not. 


> To the question of dereferencing AIL I am not clear what exactly you are describing. In my model transit node capable of recognizing AIL is doing a fixed size 20 bit lookup (label lookup :) which either reveleas local action or not. 


I’m trying to point out that a transit node wil do that 20 bit lookup and needs to find an indication of what its local action should be. Even if a node is expected to take no actions, it would need to be configured to do nothing and simply forward. Thus, the configuration must include every node along the path, not just the nodes where there are actions.

Tony