Ivan is making a good point that switch's acting as ToR's have routing 
capability in them as well.   This should be documented as a state of reality. 

--
Paul Unbehagen


On Jun 19, 2012, at 8:14 AM, "Joel M. Halpern" <[email protected]> wrote:

> Please do not aggravate the mess marketing produced by redefining switch to 
> include router.
> 
> Yours,
> Joel
> 
> 
> On 6/19/2012 6:17 AM, Ivan Pepelnjak wrote:
>> It’s the classic “what is a SWITCH” confusion caused by some marketing
>> whiz more than a decade ago. I’m not too familiar with what you can or
>> cannot do within an ID/RFC, but the logical thing to do would be to
>> define ...
>> 
>> Switch = a network device performing packet forwarding based on L2 or L3
>> headers, or a combination of both
>> 
>> ToR = ToR switch (unless indicated otherwise)
>> 
>> ... or something similar in the General Terminology section.
>> 
>> Kind regards,
>> 
>> Ivan
>> 
>> *From:*[email protected] [mailto:[email protected]] *On Behalf
>> Of *LASSERRE, MARC (MARC)
>> *Sent:* Tuesday, June 19, 2012 12:07 PM
>> *To:* Joel M. Halpern; Benson Schliesser
>> *Cc:* [email protected]
>> *Subject:* Re: [nvo3] call for adoption: draft-lasserre-nvo3-framework-02
>> 
>> It was certainly not a deliberate change to imply that L3 was not needed…
>> 
>> Could you suggest which sentence(s) need clarification?
>> 
>> Thanks,
>> 
>> Marc
>> 
>> -----Original Message-----
>> From: [email protected] <mailto:[email protected]>
>> [mailto:[email protected]] On Behalf Of Joel M. Halpern
>> Sent: Tuesday, June 19, 2012 1:27 AM
>> To: Benson Schliesser
>> Cc: [email protected] <mailto:[email protected]>
>> Subject: Re: [nvo3] call for adoption: draft-lasserre-nvo3-framework-02
>> 
>> I probably would have sent a private comment, but not bothered the list,
>> 
>> if it was just ToR entities.  But the document has changed what the ToR
>> 
>> entities are connect to from being switches / routers to being switches.
>> 
>>   It is that change which concerns me, and for which I seek explanation.
>> 
>> Yours,
>> 
>> Joel
>> 
>> PS: I actually agree that the common usage is ToR switch, and the common
>> 
>> deployment is to put L2 devices in that place in the topology.
>> 
>> On 6/18/2012 7:20 PM, Benson Schliesser wrote:
>> 
>> > Hi, Joel.
>> 
>> >
>> 
>> > I would like for the authors to respond with their own comments. But
>> speaking only for myself (as an individual):
>> 
>> >
>> 
>> > I think that common usage of the unqualified term "ToR" generally
>> refers to a "ToR switch". While the term "ToR" literally refers to a
>> location, and could be used to describe a "ToR router" or "ToR storage
>> array" etc, in my experience the definition in the framework draft is
>> fairly accurate. (And moreover, "switch" isn't necessarily limited to
>> L2... forwarding != routing, and encap / tunneling makes this even more
>> confusing.)
>> 
>> >
>> 
>> > But regardless, I think the definition of "ToR" is more-or-less
>> inconsequential to the framework. We should get it right, of course. But
>> it's more important that we define the NVE correctly. And the NVE could
>> perhaps be resident in many types of device, including a device that is
>> not exactly a router but does have L3 interface(s).
>> 
>> >
>> 
>> > In the draft, the ToR concept is introduced in an "example of
>> multi-tier DC network architecture". I know from experience that there
>> are many possible variations on where the access and aggregation layers
>> are located. Do you think the authors should make the example more
>> generic, perhaps change ToR to "access" or something like that? It's not
>> clear to me what's best here - suggestions would be appreciated.
>> 
>> >
>> 
>> > Cheers,
>> 
>> > -Benson
>> 
>> >
>> 
>> >
>> 
>> > On Jun 18, 2012, at 5:07 PM, Joel M. Halpern wrote:
>> 
>> >
>> 
>> >> I sent the comment below to the authors, upon reviewing the diffs
>> from the previous version of this draft.  I would appreciate
>> clarification on this issue before the WG adopts this document as a
>> basis for further work:
>> 
>> >>
>> 
>> >> In looking at the latest revision of this draft, the text seems to
>> have moved from describing the devices at the ToR as switches / routers
>> to refering to them as just switches.  I can not tell if this change is
>> because the authors understand switch to include IP forwarding device
>> (possibly with IP routing protocol support), or if there is a change in
>> capabilities envisioned.
>> 
>> >> If the former, it should be stated explicitly, since it is an
>> unusual usage.
>> 
>> >> If the later, I am confused as the document then very clearly states
>> that the data center interconnect devices (now referred to in section
>> 1.3 as switches) are L3 capable devices.  In fact, the premise of the
>> document requires such L3 capable devices (usually known as routers.)
>> Thus, teh sentence "Core switches are usually Ethernet switches, but can
>> also support routing capabilities" seems very strange.  switches !=
>> routers.  And this document and the WG charter requires those devices to
>> support L3 capabilities.
>> 
>> >>
>> 
>> >> Thank you,
>> 
>> >> Joel M. Halpern
>> 
>> >>
>> 
>> >> On 6/18/2012 5:51 PM, Benson Schliesser wrote:
>> 
>> >>> Dear NVO3 Participants -
>> 
>> >>>
>> 
>> >>> This message begins a two week Call for Adoption of
>> http://tools.ietf.org/html/draft-lasserre-nvo3-framework-02 by the NVO3
>> working group, ending on 02-July-2012.
>> 
>> >>>
>> 
>> >>> Please respond to the NVO3 mailing list with any statements of
>> approval or disapproval, along with any additional comments that might
>> explain your position. Also, if any NVO3 participant is aware of IPR
>> associated with this draft, please inform the mailing list and/or the
>> NVO3 chairs.
>> 
>> >>>
>> 
>> >>> Thanks,
>> 
>> >>> -Benson & Matthew
>> 
>> >>>
>> 
>> >>> _______________________________________________
>> 
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>> 
>> >>> [email protected] <mailto:[email protected]>
>> 
>> >>> https://www.ietf.org/mailman/listinfo/nvo3
>> 
>> >>>
>> 
>> >>
>> 
>> >> _______________________________________________
>> 
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>> 
>> >> [email protected] <mailto:[email protected]>
>> 
>> >> https://www.ietf.org/mailman/listinfo/nvo3
>> 
>> >
>> 
>> >
>> 
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>> 
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>> 
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