I have been in the same boat but some people thought it is really important to do a generic topology model in I2RS so here we go.
/js On Mon, Jun 29, 2015 at 05:06:17PM -0400, Joel M. Halpern wrote: > You may recall that I have expressed concern about many times about how > the network topology draft fits the I2RS scope. It is still not clear > to me that it is an I2RS item, although it is clearly useful for things > talking to the I2RS Agent. > > Yours, > Joel > > On 6/29/15 5:01 PM, Linda Dunbar wrote: > >Joel, Igor, Juergen, > > > >Thanks for the feedback. Actually I always thought I2RS Agent is within a > >single routing engine until reading the "I2RS Topology" draft. > > > >I see draft-ietf-i2rs-rib-info-model-06 as a very clear and good > >specification for information exchange between a routing engine and its > >client. It reflects one single node's RIBs associated with multiple > >Routing Instances supported by the routing engine. > > > >But the "I2RS Topology", which is also a very good specification > >describing the network view of topologies (which consists of multiple > >nodes and links among them), is more suited for the entity that manages > >multiple routing nodes. > > > >RIBs of one routing engine and "topology of multiple routing engines" > >definitely represent different perspectives: one is node view, another one > >is the network view. > > > > > >In order to make I2RS widely adopted by the industry, it is very important > >not to make it too complicated. Routing is not simple to start with, > >therefore, it becomes especially more important to keep I2RS specification > >simple and to the point. > > > >Therefore, I suggest to have a paragraph in the "network-topo" draft to > >describe that this is for the network view, it is for clients who > >manage/monitor multiple routing engines. > > > >My two cents. > > > >Linda > > > >-----Original Message----- > >From: Igor Bryskin [mailto:[email protected]] > >Sent: Monday, June 29, 2015 1:33 PM > >To: Joel M. Halpern; Linda Dunbar; Juergen Schoenwaelder > >Cc: [email protected]; '[email protected]'; [email protected]; Hariharan > >Ananthakrishnan; [email protected]; [email protected]; Jan Medved (jmedved) > >Subject: RE: [i2rs] comments to draft-ietf-i2rs-yang-network-topo-01 > > > >I agree with Joel, > > > >To answer Linda's question: if I2RS agent manages/represnts multiple > >physical devices, the interface between the agent and the devices is out > >of scope of I2RS. Note that such interface needs to be standardized only > >if one considers a scenario where an I2RS agent controls devices from > >different vendors. IMHO this scenario is unlikely, and at least for now it > >is safe to assume that said interface is private. > > > >Cheers, > >Igor > > > >-----Original Message----- > >From: i2rs [mailto:[email protected]] On Behalf Of Joel M. Halpern > >Sent: Monday, June 29, 2015 2:01 PM > >To: Linda Dunbar; Juergen Schoenwaelder > >Cc: [email protected]; '[email protected]'; [email protected]; Hariharan > >Ananthakrishnan; [email protected]; [email protected]; Jan Medved (jmedved) > >Subject: Re: [i2rs] comments to draft-ietf-i2rs-yang-network-topo-01 > > > >Juergen is correct that by the I2RS definition an I2RS Agent is part of, > >and associated with, a single routing element. > > > >It is true that the routing element may itself be a controller supporting > >and interacting with multiple forwarding elements. That is not required, > >and not discussed, by I2RS. As far as I2RS is concerned, the multiplicity > >is that the relationship between I2RS Clittns and I2rS agents is N:M. > >That is, a client may be working with multiple agents, > >and an agent may be communicating with multiple clients. But it is > >still the case that the agent is collocated with the routing system, and > >is not in a separate controller from the routing system. > > > >Yours, > >Joel > > > >On 6/29/15 10:46 AM, Linda Dunbar wrote: > >>Juergen, > >> > >>One I2RS agent can interface with multiple routing elements. > >> > >>The network view (which consists of multiple nodes, i.e. topology) has to > >>be over multiple nodes. Therefore, it is the interface between client and > >>Agent. Whereas, there are commands to individual routing element. > >> > >>Linda > >>-----Original Message----- > >>From: Juergen Schoenwaelder > >>[mailto:[email protected]] > >>Sent: Monday, June 29, 2015 3:28 AM > >>To: Linda Dunbar > >>Cc: '[email protected]'; [email protected]; Jan Medved (jmedved); > >>[email protected]; [email protected]; Hariharan Ananthakrishnan; > >>[email protected] > >>Subject: Re: [i2rs] comments to draft-ietf-i2rs-yang-network-topo-01 > >> > >>Linda, > >> > >>according to draft-ietf-i2rs-architecture-09, an I2RS agent is part of a > >>routing element. I am not sure your understanding "I2RS Agent is like the > >>SDN controller" is consistent with the architecture document. > >> > >>/js > >> > >>On Fri, Jun 26, 2015 at 05:03:25PM +0000, Linda Dunbar wrote: > >>>Alex, et al, > >>> > >>>The I2RS architecture depicts two types of interfaces: > >>> > >>>- One is the interface between Agent and Client, and > >>> > >>>- another is the interface between Agent and Routing entities. > >>> > >>> > >>>The network model and inventory are more for the interface between Agent > >>>and the Clients, isn't it? One single routing engine doesn't need to > >>>know the overall topology and inventory information of other nodes, even > >>>though some may do. > >>> > >>> > >>>And the /nd:network/nd:node and Termination points are more for the > >>>interface between the Agent and the Forwarding Engine, isn't it? > >>> > >>>IMHO, the information models should be oriented around the I2RS > >>>architecture. I.e. with description on where those information models > >>>are applicable, making it easier to differentiate from other IETF WGs > >>>work (such as L2VPN, L3VPN, or SFC). I recall there were some debates at > >>>the Dallas I2RS session. > >>> > >>>I2RS Agent is like the SDN controller, which can inform clients about > >>>the topology information, instruct routes to routing engine of multiple > >>>nodes, and retrieve link & termination points status from each of those > >>>nodes. > >>> > >>>The "Service Overlay" in Section 3.4.8 is definitely meant for clients > >>>not towards individual nodes. Mixing them all together make it confusing. > >>> > >>>Cheers, > >>> > >>>Linda Dunbar > >>> > >>> > >> > >>>_______________________________________________ > >>>i2rs mailing list > >>>[email protected] > >>>https://www.ietf.org/mailman/listinfo/i2rs > >> > >> > > > >_______________________________________________ > >i2rs mailing list > >[email protected] > >https://www.ietf.org/mailman/listinfo/i2rs > > -- Juergen Schoenwaelder Jacobs University Bremen gGmbH Phone: +49 421 200 3587 Campus Ring 1 | 28759 Bremen | Germany Fax: +49 421 200 3103 <http://www.jacobs-university.de/> _______________________________________________ i2rs mailing list [email protected] https://www.ietf.org/mailman/listinfo/i2rs
