[Nsi-wg] NML topology

"Joan A. García-Espín" joan.antoni.garcia at i2cat.net
Thu Feb 25 12:25:26 CST 2010


Agreed, good point Gigi.
Hierarchical NSA deployments *require* this to be true, since the  
distribution of entities in the service plane does not map to the one  
in the transport plane is this case.

I'm catching up the discussion, regards,
--
Joan A. García-Espín
CTX, i2CAT Foundation





El 23/02/2010, a las 18:07, Inder Monga escribió:

> OK Gigi, I think you make a good point regarding the broker function  
> of an NSA. Let me try to rephrase some of the statements:
>
>
>>> - NSI + RM = NSA. This does not mean they have to be the same  
>>> software module or function. The two functions can be distributed,  
>>> but for the outside world looking in, NSA includes the RM  
>>> capability.
>
> - NSA MAY include RM capability. NSI + Service Request Composition/ 
> Decomposition + {RM} (optional) = NSA.
>>>
>>> - ONE NSA can manage  MULTIPLE local RM's. The interface between  
>>> NSA and RM MUST NOT be a publicly accessible interface. An RM can  
>>> ONLY be controlled by a SINGLE NSA.
>
> - ONE NSA can manage ZERO TO MULTIPLE local RM's. The interface  
> between NSA and RM MUST NOT be a publicly accessible interface. An  
> RM can ONLY be controlled by a SINGLE NSA.
>
>
> On Feb 23, 2010, at 9:00 AM, Gigi Karmous-Edwards wrote:
>
>> Inder and All,
>>
>>
>> I also agree with all the below statements, with the exception that  
>> an "NSA must include RM capabilities". I can imagine an NSA that  
>> serves to process and break up a single request from a requester  
>> agent and then use the NSI to make sub-requests to other NSAs that  
>> do have RM capability. In this example the first NSA does not have  
>> resources that it directly manages and it also does not manage  
>> other NSAs.
>>
>> In this way an NSA can be a neutral entity (broker) that is not  
>> associated with network resources.
>>
>> Thanks,
>> Gigi
>>
>> Inder Monga wrote:
>>>
>>>> I think owned and controlled are synonymous for our purposes -  
>>>> even if the physical device interface is delegated to a  
>>>> subordinate function (e.g. an RM) it is still under the control  
>>>> and management of the NSA.
>>>
>>> I agree with your comments.
>>>
>>> Let me try to re-iterate the conclusions, so it can be captured in  
>>> the Architecture Document:
>>>
>>> - There can be only one owner of the resource that controls/ 
>>> manages/provisions the resource. This is known as the Resource  
>>> Manager.
>>>
>>> - All others can only "request" access (provision, schedule,  
>>> reserve) to that resource from that resource manager (RM)
>>>
>>> - The service "request" interface is "Network Service  
>>> Interface" (NSI).
>>>
>>> - NSI + RM = NSA. This does not mean they have to be the same  
>>> software module or function. The two functions can be distributed,  
>>> but for the outside world looking in, NSA includes the RM  
>>> capability.
>>>
>>> - ONE NSA can manage  MULTIPLE local RM's. The interface between  
>>> NSA and RM MUST NOT be a publicly accessible interface. An RM can  
>>> ONLY be controlled by a SINGLE NSA.
>>>
>>> - An NSA can decompose the service request to multiple sub- 
>>> requests and send them to other NSAs. An NSA that decomposes the  
>>> requests, MUST compose the responses and respond to the original  
>>> service request.
>>>
>>> Inder
>>>
>>>
>>> On Feb 23, 2010, at 5:46 AM, Jerry Sobieski wrote:
>>>
>>>> Comments in line:
>>>>
>>>> Guy Roberts wrote:
>>>>>
>>>>> Freek,
>>>>>
>>>>> Some interesting questions, here are my thoughts your questions-
>>>>>
>>>>> Requirement 1:  In my opinion each network resource should be  
>>>>> owned by only one NSA.  However, one NSA can own many  
>>>>> resources.  I guess this means that 'owned' and 'controlled' are  
>>>>> synonymous.  Though perhaps the distinction could be that a  
>>>>> passive object (eg patchcord link) can only be owned and not  
>>>>> managed?
>>>>>
>>>> It seems to me even a passive patch cable is still managed - what  
>>>> happens if it breaks?   I think the issue here is that it is a  
>>>> component of a network, and by definition it is managed by the  
>>>> associated NSA.  (What that NSA needs to do - if anythng- to  
>>>> control or manage the patch cable is a separate issue. )   Also,  
>>>> often in this whole conflagration we find that one agent controls  
>>>> the port on one end of a link and another agent controls the port  
>>>> on the other end, and these two separate objects must *MUST*  
>>>> correspond to one another, ..so the configuration is negotiated  
>>>> via protocols and the link in-between simply reflects this agreed  
>>>> config.   It is sort of moot who actually owns the resource, or  
>>>> "controls" it, as that agent simply has the priviledge of writing  
>>>> the negotiated configuration into the device...
>>>>
>>>> I think owned and controlled are synonymous for our purposes -  
>>>> even if the physical device interface is delegated to a  
>>>> subordinate function (e.g. an RM) it is still under the control  
>>>> and management of the NSA.
>>>>
>>>> Jerry
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>>>
>>>
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>
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