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
