Re: [CCAMP] [RTG-DIR] RtgDir review: draft-ietf-ccamp-general-constraint-encode-16.txt

[Leeyoung <[e-mail]>]

Hi Lou,

The original question Tomonori raised was if sub-matrices are like virtual nodes attached to connectivity matrix. The answer was no, and sub-matrix is simply a partition of connectivity matrix into smaller pieces. To that end, I added the following text in Section 2.1

   Each sub-matrix is assigned a unique Matrix ID to represent a 
   mutually exclusive set of {src port, src label, dst port, dst label} 
   from other sub-matrices. 

Let me know what you think.

Thanks,
Young

-----Original Message-----
From: Lou Berger [mailto:[e-mail]] 
Sent: Monday, February 02, 2015 3:29 PM
To: Leeyoung
Cc: Tomonori Takeda; [e-mail]; '[e-mail]'; '[e-mail]'; '[e-mail]'
Subject: Re: [RTG-DIR] RtgDir review: draft-ietf-ccamp-general-constraint-encode-16.txt

Hi Young,

I see you just published an update.  I have one question below.

On 1/23/2015 3:01 AM, Tomonori Takeda wrote:
> Hi Young,
>
> OK, thanks,
>
> Tomonori
>
> -----Original Message-----
> From: Leeyoung [mailto:[e-mail]] 
> Sent: Thursday, January 22, 2015 2:44 AM
> To: Tomonori Takeda（武田知典）; Leeyoung; [e-mail]
> Cc: '[e-mail]'; '[e-mail]'; '[e-mail]'
> Subject: RE: [RTG-DIR] RtgDir review: draft-ietf-ccamp-general-constraint-encode-16.txt
>
> Hi Tomonori,
>
> Thanks for your comment. Please see in-line for my response. Please let me know if the response would satisfy you. 
>
> Best regards,
> Young
>
> -----Original Message-----
> From: Tomonori Takeda [mailto:[e-mail]] 
> Sent: Wednesday, January 21, 2015 12:48 AM
> To: Leeyoung; [e-mail]
> Cc: '[e-mail]'; '[e-mail]'; '[e-mail]'; Tomonori Takeda
> Subject: RE: [RTG-DIR] RtgDir review: draft-ietf-ccamp-general-constraint-encode-16.txt
>
> Hi Young,
>
> Thanks.
>
> Two follow-up questions/comments.
> (I am fine with other points, which you already addressed in the updated draft.)
>
>> 2) In section 2.1, it says "two matrices will not have the same {src port, src label, dst port, dst label}". To be precise, I guess this should be > "two matrices will not have the same {src port, src label}, and two matrices will not have the same {dst port, dst label}"?
>>
>> YOUNG>> I think your suggestion may be too restrictive. For instance, if we have one source (port 1) and one destination (port 2) with two labels > each. Then we would have: {(1,1,2,1), (1,1,2,2), (1,2,2,1), (1,2,2,2)} I think with the current statement, we can send this info in any combination > of multiple matrices, which I think perfectly fine. With your suggestion, I would not be able send (1,1,2,1) and (1,1,2,2) together. Why would this > not be made possible? My take is as long as each submatrix represents a set of disjoint quadruples, that should be allowed.
> My reading of "two matrices will not have the same {src port, src label, dst port, dst label}" is as follows.
>
> <Example A>
>
>   input port=1  --> Submatrix#1 --> output port=2
>   input label=1                     output label=1
>
>   input port=1  --> Submatrix#2 --> output port=2
>   input label=1                     output label=2
>
>   This is allowed.
>
> <Example B>
>
>   input port=1  --> Submatrix#1 --> output port=2
>   input label=1                     output label=1
>
>   input port=1  --> Submatrix#2 --> output port=2
>   input label=1                     output label=1
>
>   This is not allowed.
>
> <Example C>
>
>   input port=1  --> Submatrix#1 --> output port=2
>   input label=1                     output label=1
>
>   input port=1  --> Submatrix#2 --> output port=2
>   input label=2                     output label=2
>
>   This is allowed.
>
> Is above understanding correct?
> If so, I am not sure how example A works, since I am not sure what is the indentifier to direct from input to each submatrix.
>
> Maybe I am mis-understanding what sub-matrix is. I thought sub-matrix is a sort of virtual node, splitting the single matrix (or switch) into smaller pieces.

Can you explain how the revised text clarifies this point?

Thanks,
Lou

> ....