Still trying to find an example of a case in which the term Virtual Network could not be used instead of Virtual Network Instance. And more importantly, given that Virtual Network is a defined term, why does Virtual Network Instance need a definition given that "Instance" in this case has the normal English meaning of "instance". And most importantly, let's not define a Virtual Network Instance as "a specific instance of a virtual network". Reminds of the Star Trek Movie:
SPOCK: And who is the Creator? ILIA PROBE: The Creator is that which created V'Ger. KIRK: Who is V'Ger? ILIA PROBE: V'Ger is that which seeks the Creator. Joe Pelissier -----Original Message----- From: smith, erik [mailto:[email protected]] Sent: Thursday, June 27, 2013 3:49 PM To: Eric Gray; Joe Pelissier (jopeliss); [email protected] Subject: RE: Virtual Network - what's an instance? 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:[email protected]] > 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
