So this is because that the problem statement already uses it for different meaning.
Should the framework draft support the consistency to L2VPN/L3VPN or the nvo3 problem statement? L2/L3VPN documents were generated much early without the description issues. Regards, Lucy > -----Original Message----- > From: Black, David [mailto:[email protected]] > Sent: Friday, June 28, 2013 10:39 AM > To: Lucy yong; [email protected] > Cc: Black, David > Subject: RE: Virtual Network - what's an instance? > > HI Lucy, > > Short answer: the problem statement draft's use of "virtual network > instance" > and much of the discussion here (including Eric's note below) does not > limit > the scope of "virtual network instance" (VNI) to "on a device". > > The framework draft needs a term for that concept (portion of a > specific > virtual network that is on a specific device") and as of now, "virtual > network instance" has been taken by the problem statement draft with a > broader meaning, making VNI problematic for that purpose. > > IMHO, We need to decide whether a "virtual network instance" is limited > to > "on a device" or not and modify the problem statement or framework > draft > accordingly. > > Thanks, > --David > > > -----Original Message----- > > From: [email protected] [mailto:[email protected]] On Behalf > Of Lucy > > yong > > Sent: Friday, June 28, 2013 10:44 AM > > To: Eric Gray; smith, erik; Joe Pelissier (jopeliss); [email protected] > > Subject: Re: [nvo3] Virtual Network - what's an instance? > > > > Here is my 2cent. > > > > Why do we now run into the language and term conflict issue in nvo3? > > > > We used similar terms such as VSI, VFI, VRI etc in L2VPN and L3VPN > before to > > present multiple xx instances on a device. There are many documents > developed > > in L2VPN and L3VPN WGs. We did not have problem there. > > > > Regards, > > Lucy > > > > > > > > > > > -----Original Message----- > > > From: [email protected] [mailto:[email protected]] On > Behalf Of > > > Eric Gray > > > Sent: Friday, June 28, 2013 6:51 AM > > > To: smith, erik; Joe Pelissier (jopeliss); [email protected] > > > Subject: Re: [nvo3] Virtual Network - what's an instance? > > > > > > Erik, > > > > > > Well, one issue is that we would minimally need to include "VNI" in > an > > > acronym expansion. I believe we can all agree that the English > > > language > > > interpretation of "instance" fits the way we are using it. But > this > > > may > > > not be important enough to worry about, given how late in the cycle > we > > > are in discussing this WRT to framework draft, and - if the English > > > usage > > > is correct - then the "definition" is also correct. > > > > > > In fact, it would have been nice if we could have used the acronym > VNI > > > instead of spelling it out in the problem statement draft. It > might > > > have > > > been a whole page shorter. > > > > > > For many of us, there is a reason to distinguish a VN from a VNI. > > > > > > For instance, in talking about the various approaches that might be > > > used > > > to implement virtual network overlays, one might use the phrase > > > "specific > > > VN" to mean a VN of a specific type, but not necessarily a specific > VNI. > > > > > > A specific VN might - for instance - be a VLAN, or an IP subnet, > > > without > > > being a specific instance of either. Therefore, it is possible to > > > distinguish > > > a "specific VN" from a "specific VNI." > > > > > > Either a VN, or a VNI may be implemented using BGP/MPLS VPNs, VPLS, > > > NVGRE, etc. In the VN case, we may talk about the > technology/approach > > > used while in the VNI case, were talking about a specific VN > instance. > > > > > > Your reference to "VNID" below doesn't help and may be an > illustrative > > > example of why the distinction is needed. For some approaches that > may > > > be used, the technology provides its own "VNID" while for others, > > > either > > > the way that the VN would otherwise be identified is more > complicated > > > than desired (hence a numerical identifier that maps to a more > complex > > > real identification may be useful), or there isn't a way to > identify a > > > VN of > > > that type at present (so we invent one). > > > > > > A VN of a certain type may be identified by a VNID of a certain > type. > > > A VNI > > > is identified by a specific VNID for its associated type. > > > > > > -- > > > Eric > > > > > > -----Original Message----- > > > From: smith, erik [mailto:[email protected]] > > > Sent: Thursday, June 27, 2013 6:49 PM > > > To: Eric Gray; Joe Pelissier (jopeliss); [email protected] > > > Subject: RE: Virtual Network - what's an instance? > > > Importance: High > > > > > > Ha..that's funny... I was going to complement you on your correct > > > spelling (because it's the way the everyone spells my name by > > > default)! :-) > > > > > > To borrow your format: > > > > > > Specific VNs (i.e. - VN instances) are identified by a VNID > (Virtual > > > Network ID) > > > > > > My point is, if the statement "VLAN 41 may be an instance of the > VLAN > > > concept" is technically correct (and I believe it is), then why > > > wouldn't "VN 41 may be an instance of the VN concept", "the > tenant's > > > VN" or "there's a problem with VN 41" also be acceptable? Why > should > > > we have to append "I" to "VN" in each case? If the answer is "we > > > don't", then can anyone provide a specific scenario where VNI must > be > > > used? > > > > > > Regards, Erik > > > > > > > > > -----Original Message----- > > > From: Eric Gray [mailto:[email protected]] > > > Sent: Thursday, June 27, 2013 4:28 PM > > > To: smith, erik; Joe Pelissier (jopeliss); [email protected] > > > Subject: RE: Virtual Network - what's an instance? > > > > > > Erik, > > > > > > Weird talking to someone whose name is "correctly spelled" > > > according to most of my Ericsson colleagues - which is already > strange > > > enough. :-) > > > > > > Specific VLANs (i.e. - VLAN instances) are identified by a VID > > > (VLAN ID). > > > Specific IP subnets (i.e. - IP Subnet instances) are identified in > a > > > somewhat more complicated way. > > > > > > If we need to talk about generic concepts, we need to > > > differentiate the generic concept of a virtual network from the > equally > > > generic concept of a specific instance of a virtual network. > > > > > > -- > > > Eric > > > > > > -----Original Message----- > > > From: smith, erik [mailto:[email protected]] > > > Sent: Thursday, June 27, 2013 4:11 PM > > > To: Eric Gray; Joe Pelissier (jopeliss); [email protected] > > > Subject: RE: Virtual Network - what's an instance? > > > Importance: High > > > > > > Eric, if VNI is required to describe an instance of a VN, why isn't > > > VLANI required to describe an instance of a VLAN? > > > > > > Regards, Erik > > > > > > -----Original Message----- > > > From: [email protected] [mailto:[email protected]] On > Behalf Of > > > Eric Gray > > > Sent: Thursday, June 27, 2013 3:51 PM > > > To: Joe Pelissier (jopeliss); [email protected] > > > Subject: Re: [nvo3] Virtual Network - what's an instance? > > > > > > Joe, > > > > > > At the end of the day, every definition is either a tautology, or > > > it is wrong. > > > > > > As one of my colleagues has put it, a VN is a concept and a VNI > > > is a realization of the concept. > > > > > > VLAN 41 may be an instance of the VLAN concept. > > > > > > The subnet associated with a router interface IP address and its > > > associated net-mask is an instance of the IP subnet concept. > > > > > > A VN is intended to be a generic concept that includes multiple > > > virtual-network types. A VNI is an instance (or realization?) of a > VN. > > > > > > -- > > > Eric > > > > > > -----Original Message----- > > > From: [email protected] [mailto:[email protected]] On > Behalf Of > > > Joe Pelissier (jopeliss) > > > Sent: Wednesday, June 19, 2013 6:29 PM > > > To: [email protected] > > > Subject: Re: [nvo3] Virtual Network - what's an instance? > > > > > > Maybe it's just me, but the definition of VNI does not seem useful: > > > > > > "Virtual Network Instance (VNI): A specific instance of a VN." > > > If someone did not understand what a Virtual Network Instance is, > then > > > simply adding the word "specific" does not help much. Essentially, > a > > > VNI is a VN - the terms appear synonymous, so it would be best to > > > simply eliminate the VNI term. > > > > > > My $0.02 worth... > > > Joe Pelissier > > > > > > -----Original Message----- > > > From: [email protected] [mailto:[email protected]] On > Behalf Of > > > Black, David > > > Sent: Wednesday, June 19, 2013 7:48 AM > > > To: LASSERRE, MARC (MARC) > > > Cc: [email protected] > > > Subject: Re: [nvo3] Virtual Network - what's an instance? > > > > > > Marc, > > > > > > Good - that'll work well, and I'm assuming that you'll bring the > rest > > > of the draft into line, as there is usage of the VNI acronym to > refer > > > to the NVE-local portion of a VN (what I refer to as VNLI below). > > > > > > Thanks, > > > --David > > > > > > > -----Original Message----- > > > > From: LASSERRE, MARC (MARC) [mailto:marc.lasserre@alcatel- > lucent.com] > > > > Sent: Wednesday, June 19, 2013 3:54 AM > > > > To: Black, David > > > > Cc: [email protected] > > > > Subject: RE: Virtual Network - what's an instance? > > > > > > > > Hi David, > > > > > > > > In the soon-to-be-published revision of the framework draft, the > VN & > > > > VNI definitions stand as: > > > > > > > > Virtual Network (VN): A VN is a logical abstraction of a physical > > > > network that provides L2 or L3 network services to a set of > Tenant > > > > Systems. A VN is also known as a Closed User Group (CUG). > > > > > > > > Virtual Network Instance (VNI): A specific instance of a VN. > > > > > > > > I think that this addresses your concern. > > > > > > > > Marc > > > > > > > > > -----Original Message----- > > > > > From: [email protected] [mailto:[email protected]] On > > > Behalf > > > > > Of Black, David > > > > > Sent: Wednesday, June 19, 2013 1:24 AM > > > > > To: [email protected] > > > > > Subject: [nvo3] Virtual Network - what's an instance? > > > > > > > > > > In working on some control plane draft material, I've run > across an > > > > > inconsistency in the use of the concept of a "virtual network > > > > > instance" > > > > > (or VNI) between the problem statement and framework drafts. > > > > > > > > > > The problem statement draft does not define "virtual network > > > instance" > > > > > and uses that term more or less interchangeably with "virtual > > > network" > > > > > to refer to a specific virtual network. Here's an example with > > > both > > > > > terms used in the same sentence near the top of p.5: > > > > > > > > > > A key requirement is that each > > > > > individual virtual network instance be isolated from other > > > virtual > > > > > network instances, with traffic crossing from one virtual > > > network > > > > > to > > > > > another only when allowed by policy. > > > > > > > > > > The framework draft defines Virtual Network Instance (VNI) as > > > > > effectively being the portion of a virtual network that is > > > > > instantiated in an NVE: > > > > > > > > > > VNI: Virtual Network Instance. This is one instance of a > > > > > virtual > > > > > overlay network. It refers to the state maintained for a > > > > > given VN on > > > > > a given NVE. Two Virtual Networks are isolated from one > > > > > another and > > > > > may use overlapping addresses. > > > > > > > > > > Something's wrong here. Back in February, Thomas Narten > proposed > > > > > that we use the problem statement terminology consistently in > the > > > > > framework draft, but there hasn't been any further discussion. > > > > > > > > > > Speaking for myself, the problem statement draft's usage seems > more > > > > > intuitive (an "instance" of a virtual network is a virtual > network, > > > > > not part of one, as is the case in the framework draft), but > we've > > > > > had the VNI acronym around in the framework draft for a good > long > > > > > time now. > > > > > > > > > > If it were ok to change the framework draft, I would prefer: > > > > > > > > > > VNLI: Virtual Network Local Instance. This is an > instance > > > of a > > > > > virtual overlay network on a specific NVE. The VNLI refers > to > > > the > > > > > local state and associated processing for a given VN on > a > > > given > > > > > NVE. Within an NVE, VNLIs are isolated from one another > and > > > > > may use overlapping network addresses. > > > > > > > > > > But that's just my 0.02 - what should be done about this? > > > > > > > > > > Thanks, > > > > > --David > > > > > ---------------------------------------------------- > > > > > David L. Black, Distinguished Engineer EMC Corporation, 176 > South > > > > > St., Hopkinton, MA 01748 > > > > > +1 (508) 293-7953 FAX: +1 (508) 293-7786 > > > > > [email protected] Mobile: +1 (978) 394-7754 > > > > > ---------------------------------------------------- > > > > > > > > > > > > > > > _______________________________________________ > > > > > nvo3 mailing list > > > > > [email protected] > > > > > https://www.ietf.org/mailman/listinfo/nvo3 > > > > > > > > _______________________________________________ > > > nvo3 mailing list > > > [email protected] > > > https://www.ietf.org/mailman/listinfo/nvo3 > > > _______________________________________________ > > > nvo3 mailing list > > > [email protected] > > > https://www.ietf.org/mailman/listinfo/nvo3 > > > _______________________________________________ > > > nvo3 mailing list > > > [email protected] > > > https://www.ietf.org/mailman/listinfo/nvo3 > > > > > > > > > _______________________________________________ > > > nvo3 mailing list > > > [email protected] > > > https://www.ietf.org/mailman/listinfo/nvo3 > > _______________________________________________ > > nvo3 mailing list > > [email protected] > > https://www.ietf.org/mailman/listinfo/nvo3 _______________________________________________ nvo3 mailing list [email protected] https://www.ietf.org/mailman/listinfo/nvo3
