We could do an OpenDaylight implementation of Signaling Free Mcast over the 
OVS. Set the flow table to catch PIM and IGMP as packetIn from OVS to the ODL 
controller. That would easily translate to mapping (NVA) API and wire the OVS 
to mcast tree using flows. OVS + ODL will form the NVE.

There may be interest as people look for at least easy tap solution 
mapping-flow that can be enhanced to support app-mcast.

--szb

On Aug 31, 2014, at 9:49 AM, "Dino Farinacci" 
<[email protected]<mailto:[email protected]>> wrote:

Dino,

At Toronto NV03 session, you suggested that 
draft-ghanwani-nvo3-app-mcast-framework can use LISP's signal free multicast 
scheme.
After studying the draft-farinacci-lisp-signal-free-multicast-00, I agree that 
the proposed scheme can definitely solve the problem of application initiated 
multicast in environment where underlay network don't support any IP multicast 
protocol.

The design allows for either unicast or multicast RLOCs to be registered to the 
mapping system. So LISP signal-free multicast can be used when the underlay 
supports multicast.

 But there are some issues of using the LISP's signal free multicast mechanism 
in Data Centers when NVEs, especially the server based hypervisor virtual 
switches,  don't ( or can't) support the "General Receiver-site procedure" 
documented in the "draft-farinacci-list-signal-free-multicast-00".  The general

Whatever the application is going to use to tell the network what multicast 
groups are joined can be used as well.

receiver-site procedure requires egress edge (i.e. egress NVE) to terminate 
IGMP or PIM messages. But many NVEs (server based virtual switches) don't 
terminate IGMP nor PIM.

Well if the virtual switch supports LISP, then the app directly tells the xTR 
which groups it is joining.

And if the LISP xTR is one-hop northbound from the virtual switch, you can bet 
the virtual switch does IGMP snooping.

 Therefore, NVO3 needs a simpler scheme for "Receiver NVEs".   
draft-ghanwani-nvo3-app-mcast-framework-00 suggests all IGMP messages are sent 
to "multicast server".

That is not simpler - that adds a new component to the network.

And if you IGMP to a server why is that different than registering to a 
map-server.

But since there is no precise serial spec'ed on how the NVE-to-NVA protocol 
works no one can tell what can be leveraged for multicast.

LISP-signal-free-multicast works because the LISP mapping system protocols are 
well specified, implemented, and deployed.

 Or "Multicast server" can fake "IGMP query" to all the NVEs, which forwarded 
down to applications. The reply (IGMP report) can be automatically sent back to 
"multicast server" without NVE doing anything extra.

What do you think?

You want multicast routers to attach to the overlay. They don't send IGMP 
packets to each other.

IGMP is a host-to-router protocol and has been abused to be a host-to-switch 
protocol. Let's stop the abuse.  :-)

Dino



Linda

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