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On 06/17/2015 02:24 PM, Cathy Zhang wrote:
> Hi Nicolas,
>
> Thanks for your suggestion. Yes, we can add Application ID to the
> parameter of the flow classifier/filter. The next updated version will
> reflect this. Actually in its existing design, the parameter field of
> the flow classifier can be extended in the future to include more flow
> descriptors for more granular differentiation of flows.
>
> Per earlier suggestion from Isaku etc., we can also add a “context”
> field to the service chain API. The context field will include
> information such as “the encapsulation mechanism” used by the service
> functions in the chain, which can be NSH, VLAN, none etc. so that the
> Service Function Forwarder (the vSwcitch) knows whether it should act as
> a SFC proxy or not and if acting as a Proxy, what is the chain
> correlation mechanism between the Service Function Forwarder and the
> Service Function.
>
> Any comments/questions/suggestions?

My only comment is the same as the one I placed on the telco-wg service 
function chaining spec [1]. That is, I don't believe this work should be 
done in the Neutron API at all.

Rather, I believe these concepts belong in an entirely separate (from 
Neutron) API endpoint and project. Of course, the reference 
implementation of service function chaining would make calls out to the 
Neutron API for "plumbing" purposes -- e.g. make me a port on this L2 
network, etc.

I strongly believe having a separate project for service function 
chaining is the right long-term strategy for this, since the SFC 
concepts are not the same as Neutron's. SFC isn't really about 
networking (in terms of connectivity). Instead, SFC is about the 
*orchestration* of virtual (and sometimes non-virtual) resources into a 
hot-reconfigurable pipeline for directing packets across the network.

Thoughts?
-jay

[1] https://review.openstack.org/#/c/169201/