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"discuss" <discuss-bounces at openvswitch.org> wrote on 06/14/2016 10:31:40
PM:

> From: John McDowall <jmcdowall at paloaltonetworks.com>
> To: Na Zhu <nazhu at cn.ibm.com>
> Cc: Srilatha Tangirala/San Francisco/IBM at IBMUS, "OpenStack
> Development Mailing List \(not for usage questions\)" <openstack-
> dev at lists.openstack.org>, discuss <discuss at openvswitch.org>
> Date: 06/14/2016 10:48 PM
> Subject: Re: [ovs-discuss] [openstack-dev] [OVN] [networking-ovn]
> [networking-sfc] SFC andOVN
> Sent by: "discuss" <discuss-bounces at openvswitch.org>
>
> Juno,
>
> It is a container for port-pair-groups and flow-classifier. I
> imagine there could be more the than one port-chain per switch. Also
> we may want to extend the model beyond a single lswitch

I agree that there could be more than one port-chain per switch, determined
by the flow classifier.

What I'm confused by is:

1. Why are items only recorded in logical switches?  I would think
that I could also attach an SFC to a logical router - although I admit
that the current neutron model for ports doesn't really allow that
easily.  Couple that with the change of name from Logical_Port to
Logical_Switch_Port, and I'm left wondering if we aren't better off
with the following "weak" links instead:
-the Port_Chain includes the logical switch as an external_id
-each Port_Pair_Group includes the Port_Chain as an external_id
-each Port_Pair includes the PPG as an external_id
-each Logical_Switch_Port includes the PP as an external_id

I *think* that *might* allow me (in the future) to attach a port chain
to a logical router by setting the logical router as an external_id and
using Logical_Router_Ports to make up the PPs...


2. I still don't see what Logical_Flow_Classifier is buying me that
ACL doesn't - I can codify all of the classifiers given in the match
criteria of an ACL entry and codify the first PPG of the SFC as
the action of the ACL entry...

Ryan
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