Hi Lothar,
I agree with you that the discussion that is going on about the term TSI is a little bit confusing. In my opinion, it is best to think about the TSI in regard to the containment tree proposed in draft-kreeger-nvo3-hypervisor-nve-cp-01. In its simplest case the containment tree might look like this: TSI -- VN -- MAC -- IP. Therefore, a TSI is nothing more than a conceptual interface which connects a Tenant System (TS) to a Virtual Network Instance (VNI). I personally like the new term TSI more than the old one (VNIC), because it does not make any assumption about the implementation of the interface, i.e. the TSI can be for example a logical NIC or a physical NIC, and it can be VLAN-tagged or untagged. If I understand the current NVE reference model correctly, there is a one-to-one relationship between the TSI on the TS side and the VAP on the NVE side, i.e. each TSI is logically associated with exactly one VAP. I do not think it is a good idea to call the TSI an "Overlay network interface", because the TSI is not directly involved in creating the overlay network. This is the job of the NVE which conceptually consists of one or more VNIs and the Overlay Module. Thanks, Florian >>> "Reith, Lothar" <[email protected]> 21.04.13 13.44 Uhr >>> Given that the term TSI lead to a long discussion and perhaps even confusion, I like to offer some abstraction help. Please consider any network can be drawn as a graph with vertices and points representing the endpoints of the vertices. Agreed? If you agree, please consider which of the 3 options the TSI represents: a) The point in the tenant system that interfaces towards the network b) The point in the network that interfaces towards the tenant system c) The vertice that connects 2 points (one in the network that is closest to the tenant system and one in the tenant system that is closest to the network) Do all agree that it is b) ? If yes, do you agree that we may be better of in renaming Tenant System Interface as “Overlay network interface”? Or did I get something totally wrong? Lothar Von: [email protected] [mailto:[email protected]] Im Auftrag von Lizhong Jin Gesendet: Freitag, 19. April 2013 19:05 An: [email protected]; Lawrence Kreeger Betreff: Re: [nvo3] NVO3 Terminology changes Hi Larry, I wonder if point C or D is feasible in implementation. In my understanding, the TSI must be a virtual port which could be associated with the special VN, and transmit/receive packets from tenant system (the virtual port terminology is used in many switch chip). If we use one IP address, we could not treat it as a virtual port. One simple example, if packet with broadcast IP address received, will this packet be send to IP_a and IP_b on the same vNIC? I don't think we need to define such kind of detail for TSI. The TSI definition is implementation related. I could define the TSI with a VLAN (piont B in your figure), or define TSI with a priority queue within one vNIC. BTW, I like the name TSI, and remove NIC/vNIC/pNIC. pNIC is closely related with data transfer between network and host stack, and it is usually a controller without MAC&PHY. vNIC is a driver function or virtual function(defined by SR-IOV). A TSI could also be a vNIC teaming interface by teaming driver. So "interface" is a appropriate name to define a Tx/Rx channel between tenant system and VN. Regards Lizhong ---------- Forwarded message ---------- From: "Larry Kreeger (kreeger)" <[email protected]> To: Qin Wu <[email protected]>, Anoop Ghanwani <[email protected]>, "Black, David" <[email protected]> Cc: "[email protected]" <[email protected]>, "Reith, Lothar" <[email protected]> Date: Wed, 17 Apr 2013 16:55:50 +0000 Subject: Re: [nvo3] NVO3 Terminology changes Hi Qin, Regarding what defines a TSI, someone could choose any branch in the tree below to define as the TSI. I was assuming that the TSI would be at point A below in the tree. However, point B would correspond the the VAP. Pat had mentioned having the TSI at point D. I think if we were to define the TSI to be either point C or point D, then it would depend on the service being given (L2 or L3). I would prefer it to be at point A or B. VNIC-+-VN-+-MAC-+-IP ^ | | +-IP ... | | | | | +-MAC-+-IP | | +-IP ... | | | +-VN-+-MAC-+-IP | ^ | +-IP ... | | | | | +-MAC-+-IP | | ^ +-IP ... | | | ^ | | | | A B C D - Larry
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