> On Jul 2, 2015:2:51 AM, at 2:51 AM, Juergen Schoenwaelder
> <[email protected]> wrote:
>
> True in principle but then there is apparently also confusion about
> scope and relationship of the work to what is called an I2RS agent.
That is for sure.
> My proposal back then was to charter a short-lived WG to produce a
> generic topology model so that this important piece of work is not
> tied to any other WG with its specific scope. This proposal did not
> fly but I still believe this would have been the cleanest approach.
I would be all for this at this point. Pruning down the
scope of topology to fit into the current I2RS box (which I disagree with)
does not seem to be working out well in terms of the topo work
at the IETF. Due to this mismatch, those interested in topology will find
that outside projects such as ODL have progressed topology well beyond
what is being discussed in i2rs. For example, multi-layered topology is
a reality and there is a functional implementation of this. Maybe
the solution is to indeed pull topology out of the i2rs WG and let it progress
independently?
> Anyway, good to read that topology people plan to get together in
> Prague. Getting the right people to sit together is at the end what
> makes work move ahead.
For sure.
—Tom
>
> /js
>
> On Wed, Jul 01, 2015 at 08:41:09AM -0400, Nadeau Thomas wrote:
>>
>> I personally think its important to do a generic topology model as well
>> as provide a layered model. This is something that has and is implemented
>> and deployed, so it is clearly important and useful. Where its done is
>> nearly irrelevant just as long as it gets done.
>>
>> —Tom
>>
>>
>>> On Jun 30, 2015:1:41 AM, at 1:41 AM, Juergen Schoenwaelder
>>> <[email protected]> wrote:
>>>
>>> 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
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>>>>> 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
>>
>
> --
> 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/>
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