I'd like to see Section 3.4, "IP multicast in the underlay" expanded a bit.  

The section mentions the use of BIDIR for a scalable underlay.  The sad fact is 
that many vendors still do not fully support BIDIR in their devices (after how 
many years?) or have limitations on its use that preclude it as a viable 
option.  I'm no expert in these Underlay sort of DC to DC networks but it seems 
that SSM would not have that issue since it is basically a subset (and much 
simpler to implement and configure) of the PIM protocol and would therefore be 
available in pretty much all vendor devices that support multicast.  The 
problem is one of Source Discovery of the VTEPs (or, in the case of this draft 
I think the term is NVE) which would be the sources of the multicast traffic in 
each TS.

At the very least, I'd like to see a paragraph discussing the possible use of 
SSM as an alternative to BIDIR if the VTEP/NVE devices had a way to learn of 
each other's IP address so that they could join all SSM SPT's to 
create/maintain an underlay SSM IP Multicast tunnel solution.  This would 
greatly simplify the configuration and management of the underlay IP Multicast 
environment.

I realize that the VTEP/NVE Source Discovery problem is beyond the scope of 
this Framework document but I'd like to see the above mentioned to possibly 
encourage more work in this area if it is not already underway.


Beau Williamson
CCIE #1346 R/S Emeritus
Principal Member of Technical Staff
Corporate Engineering
metroPCS/T-Mobile
Internal: 314982
Office:   469.330.4982
Mobile:   972.679.4334


-----Original Message-----
From: MBONED [mailto:[email protected]] On Behalf Of Dino Farinacci
Sent: Tuesday, May 24, 2016 12:21 PM
To: Bocci, Matthew (Nokia - GB)
Cc: MBONED WG; <[email protected]>
Subject: Re: [MBONED] NVO3 Multicast Framework

Sorry, I thought I had. NVo3, see my comments below.

Dino

> On May 24, 2016, at 6:14 AM, Bocci, Matthew (Nokia - GB) 
> <[email protected]> wrote:
> 
> Hi Dino
> 
> Could you copy NVO3 on your comments, please?
> 
> Thanks
> 
> Matthew
> 
> From: EXT Dino Farinacci <[email protected]>
> Date: Monday, 16 May 2016 at 23:31
> To: Leonard Giuliano <[email protected]>
> Cc: MBONED WG <[email protected]>, Matthew Bocci 
> <[email protected]>, Benson Schliesser <[email protected]>
> Subject: Re: [MBONED] NVO3 Multicast Framework
> 
> I just have one minor comment. Regarding the second paragraph:
> 
> <PastedGraphic-2.png>
> 
> Using LISP-signal-free does not mean the head-end must do replication. The 
> draft indicates that a mapping system is used to decide where packets go. If 
> the mapping database indicates that packets are encapsulated to multicast 
> RLOCs, or unicast RLOCs, or both in one set, so be it.
> 
> And note if there is a single multicast RLOC, then there is no replication 
> happening at the head-end, just one packet encapsulting multicast in 
> multicast.
> 
> So what is written above is true, but it may be associated with an incorrect 
> section title.
> 
> Dino
> 
>> On May 12, 2016, at 2:52 PM, Leonard Giuliano <[email protected]> wrote:
>> 
>> MBONED,
>> 
>> The following draft recently went through WG last call in the NVO3 working 
>> group:
>> 
>> https://datatracker.ietf.org/doc/draft-ietf-nvo3-mcast-framework/
>> 
>> This doc covers multicast in data center overlay networks.  As you know, it 
>> is part of our charter in MBONED to provide feedback to other relevant 
>> working groups.  Please review and send any comments to the NVO3 WG mailing 
>> list ([email protected])- all comments will be greatly appreciated by NVO3.
>> 
>> _______________________________________________
>> MBONED mailing list
>> [email protected]
>> https://www.ietf.org/mailman/listinfo/mboned
> 
> <PastedGraphic-2.png>

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