On Thu, May 24, 2012 at 07:25:52PM +0200, ravi.ke...@telekom.com wrote: > > As for the TTL, I don't think that any OpenFlow version allows for > > matching on an IP TTL, so there is no support-by-analogy for > > matching on the MPLS TTL. Is there another reason to support > > matching on the MPLS TTL? > > I see there is a capability to match on nw_ttl so thought it would > make sense to add a match for mpls_ttl.
nw_ttl is part of the kernel-to-user interface but it is not exposed via OpenFlow. I think that the same is true of the TTL in your MPLS patch? > When IP packets traverse MPLS tunnels, IP TTL is copied into MPLS > TTL and it is copied back into IP when they exit. Hence thought of > providing a match for that. Maybe that is enough to make a case for an OpenFlow MPLS TTL match, but I don't follow. You might have to spell out the use case step-by-step for me to understand. > > > > It occurs to me that we could drop the NXAST_SET_MPLS_LABEL and > > > > NXAST_SET_MPLS_TC actions because these can be implemented through > > > > "register load" actions. OpenFlow 1.2 also dropped the similar > > > > OFPAT_ actions, for the same reason, so maybe we shouldn't bother > > > > with NXAST_ actions for them as they don't have any additional > > > > benefit for OpenFlow 1.0 with Nicira extensions. > > > > > > Same argument as above. In this case it isn't quite clear to me how > > > set_mpls_label and set_mpls_tc be implemented via reg_load. Any > > > pointers? > > > > In ovs-ofctl syntax, the "load" actions would look like this: > > load:123->NXM_OF_MPLS_TC[] > > load:5->NXM_OF_MPLS_LABEL[] > > > Thanks for the information. I will work on it after 1.1 is ready. I doubt you need to take any action to make this work. It should "just work" without any further changes. Thanks, Ben. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
