Re: [Lsr] New Version Notification for draft-wang-lsr-isis-mfi-00.txt

Aijun Wang <wangaijun@tsinghua.org.cn> Thu, 04 March 2021 14:02 UTC

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Cc: Peter Psenak <ppsenak@cisco.com>, Gyan Mishra <hayabusagsm@gmail.com>, Robert Raszuk <robert@raszuk.net>, Huzhibo <huzhibo@huawei.com>, Aijun Wang <wangaj3@chinatelecom.cn>, Tony Li <tony.li@tony.li>, lsr <lsr@ietf.org>, Tianran Zhou <zhoutianran@huawei.com>
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Subject: Re: [Lsr] New Version Notification for draft-wang-lsr-isis-mfi-00.txt
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Hi, Yali and Peter:

How about using “MFI-specified context” in stead of “MFI-specified LSDB”?
“MFI-specified context” is subdivided from a single common LSDB within the zero IS-IS instance.

Aijun Wang
China Telecom

> On Mar 4, 2021, at 21:45, wangyali <wangyali11@huawei.com> wrote:
> 
> Hi Peter,
> 
> Please see inline [Yali2]. Thanks a lot.
> 
> -----Original Message-----
> From: Peter Psenak [mailto:ppsenak@cisco.com] 
> Sent: Thursday, March 4, 2021 6:50 PM
> To: wangyali <wangyali11@huawei.com>om>; Gyan Mishra <hayabusagsm@gmail.com>om>; Robert Raszuk <robert@raszuk.net>
> Cc: Huzhibo <huzhibo@huawei.com>om>; Aijun Wang <wangaj3@chinatelecom.cn>cn>; Tony Li <tony.li@tony.li>li>; lsr <lsr@ietf.org>rg>; Tianran Zhou <zhoutianran@huawei.com>
> Subject: Re: [Lsr] New Version Notification for draft-wang-lsr-isis-mfi-00.txt
> 
> Hi Yali,
> 
>> On 04/03/2021 11:42, wangyali wrote:
>> Hi Peter,
>> 
>> Please review follows tagged by [Yali].
>> 
>> 
>> -----Original Message-----
>> From: Peter Psenak [mailto:ppsenak@cisco.com]
>> Sent: Wednesday, March 3, 2021 5:37 PM
>> To: wangyali <wangyali11@huawei.com>om>; Gyan Mishra 
>> <hayabusagsm@gmail.com>om>; Robert Raszuk <robert@raszuk.net>
>> Cc: Huzhibo <huzhibo@huawei.com>om>; Aijun Wang 
>> <wangaj3@chinatelecom.cn>cn>; Tony Li <tony.li@tony.li>li>; lsr 
>> <lsr@ietf.org>rg>; Tianran Zhou <zhoutianran@huawei.com>
>> Subject: Re: [Lsr] New Version Notification for 
>> draft-wang-lsr-isis-mfi-00.txt
>> 
>> Yali,
>> 
>>> On 03/03/2021 06:02, wangyali wrote:
>>> Hi Peter,
>>> 
>>> Thanks for your comments. Yes. I am improving this sentence. Please review the following update.
>>> 
>>> OLD: " And Level 1/Level 2 PSNP and Level 1/Level 2 CSNP containing information about LSPs that transmitted in a specific MFI are generated to synchronize the LSDB corresponding to the specific MFI."
>>> 
>>> NEW: "And Level 1/Level 2 PSNP and Level 1/Level 2 CSNP containing information about LSPs that transmitted in a specific MFI are generated to synchronize the MFI-specific sub-LSDB. Each MFI-specific sub-LSDB is subdivided from a single LSDB."
>> 
>> please specify sub-LSDB.
>> [Yali] Thanks for your comment. But to avoid introducing a new term, I change to use "MFI-specific LSDB" instead of " MFI-specific sub-LSDB ".  And we give the explanation that "Each MFI-specific LSDB is subdivided from a single LSDB."
> 
> I wonder what is the difference between "MFI-specific LSDB subdivided from a single LSDB" versus the "MFI-specific LSDB".
> [Yali2]: Actually I am trying to optimize and accurately describe the key point that multiple Update processes associated with each MFI operate on a common LSDB within the zero IS-IS instance, and each Update process is isolated from each other and does not affect each other. 
> So we say "MFI-specific LSDB subdivided from a single LSDB", which may explicitly indicate each MFI-specific LSDB shares a common LSDB but each Update process associated with a MFI is isolated. However, from your previous question and suggestions,  "MFI-specific LSDB" looks like unclear and misleading. Any good idea on improving the expression are welcome.
> 
> thanks,
> Peter
> 
>> 
>> thanks,
>> Peter
>> 
>> 
>>> 
>>> Best,
>>> Yali
>>> 
>>> -----Original Message-----
>>> From: Peter Psenak [mailto:ppsenak@cisco.com]
>>> Sent: Tuesday, March 2, 2021 5:12 PM
>>> To: wangyali <wangyali11@huawei.com>om>; Gyan Mishra 
>>> <hayabusagsm@gmail.com>om>; Robert Raszuk <robert@raszuk.net>
>>> Cc: Huzhibo <huzhibo@huawei.com>om>; Aijun Wang 
>>> <wangaj3@chinatelecom.cn>cn>; Tony Li <tony.li@tony.li>li>; lsr 
>>> <lsr@ietf.org>rg>; Tianran Zhou <zhoutianran@huawei.com>
>>> Subject: Re: [Lsr] New Version Notification for 
>>> draft-wang-lsr-isis-mfi-00.txt
>>> 
>>> Yali,
>>> 
>>> On 01/03/2021 10:49, wangyali wrote:
>>>> Hi Peter,
>>>> 
>>>> Many thanks for your feedback. First of all, I'm sorry for the confusion I had caused you from my previous misunderstanding.
>>>> 
>>>> And I want to clarify that a single and common LSDB is shared by all MFIs.
>>> 
>>> well, the draft says:
>>> 
>>> "information about LSPs that transmitted in a
>>>    specific MFI are generated to synchronize the LSDB corresponding to
>>>    the specific MFI."
>>> 
>>> If the above has changed, then please update the draft accordingly.
>>> 
>>> thanks,
>>> Peter
>>> 
>>> 
>>> 
>>>> 
>>>> Best,
>>>> Yali
>>>> 
>>>> -----Original Message-----
>>>> From: Peter Psenak [mailto:ppsenak@cisco.com]
>>>> Sent: Sunday, February 28, 2021 8:23 PM
>>>> To: Gyan Mishra <hayabusagsm@gmail.com>om>; Robert Raszuk 
>>>> <robert@raszuk.net>
>>>> Cc: Huzhibo <huzhibo@huawei.com>om>; Aijun Wang 
>>>> <wangaj3@chinatelecom.cn>cn>; Tony Li <tony.li@tony.li>li>; lsr 
>>>> <lsr@ietf.org>rg>; Tianran Zhou <zhoutianran@huawei.com>om>; wangyali 
>>>> <wangyali11@huawei.com>
>>>> Subject: Re: [Lsr] New Version Notification for 
>>>> draft-wang-lsr-isis-mfi-00.txt
>>>> 
>>>> Gyan,
>>>> 
>>>> On 26/02/2021 17:19, Gyan Mishra wrote:
>>>>> 
>>>>> MFI seems more like flex algo with multiple sub topologies sharing 
>>>>> a common links in a  topology where RFC 8202 MI is separated at the 
>>>>> process level separate LSDB.  So completely different and of course 
>>>>> different goals and use cases for MI versus MFI.
>>>> 
>>>> I would not use the fle-algo analogy - all flex-algos operate on top of a single LSDB, contrary to what is being proposed in MFI draft.
>>>> 
>>>>> 
>>>>>     MFI also seems to be a flood reduction mechanism by creating 
>>>>> multiple sub topology instances within a common LSDB.  There are a 
>>>>> number of flood reduction drafts and this seems to be another 
>>>>> method of achieving the same.
>>>> 
>>>> MFI draft proposes to keep the separate LSDB per MFI, so the above analogy is not correct either.
>>>> 
>>>> thanks,
>>>> Peter
>>>> 
>>>> 
>>>>> 
>>>>> Gyan
>>>>> 
>>>>> On Fri, Feb 26, 2021 at 7:10 AM Robert Raszuk <robert@raszuk.net 
>>>>> <mailto:robert@raszuk.net>> wrote:
>>>>> 
>>>>>       Aijun,
>>>>> 
>>>>>       How multi instance is implemented is at the discretion of a vendor.
>>>>>       It can be one process N threads or N processes. It can be both and
>>>>>       operator may choose.
>>>>> 
>>>>>       MFI is just one process - by the spec - so it is inferior.
>>>>> 
>>>>>       Cheers,
>>>>>       R.
>>>>> 
>>>>> 
>>>>>       On Fri, Feb 26, 2021 at 12:44 PM Aijun Wang <wangaj3@chinatelecom.cn
>>>>>       <mailto:wangaj3@chinatelecom.cn>> wrote:
>>>>> 
>>>>>           Hi, Robert:
>>>>> 
>>>>>           Separate into different protocol instances can accomplish the
>>>>>           similar task, but it has some deployment overhead.
>>>>>           MFIs within one instance can avoid such cumbersome work, and
>>>>>           doesn’t affect the basic routing calculation process.
>>>>> 
>>>>>           Aijun Wang
>>>>>           China Telecom
>>>>> 
>>>>>>           On Feb 26, 2021, at 19:00, Robert Raszuk <robert@raszuk.net
>>>>>>           <mailto:robert@raszuk.net>> wrote:
>>>>>> 
>>>>>>           Hi Yali,
>>>>>> 
>>>>>>               If this was precise, then the existing multi-instance
>>>>>>               mechanism would be sufficient.
>>>>>>               [Yali]: MFI is a different solution we recommend to solve
>>>>>>               this same and valuable issue.
>>>>>> 
>>>>>> 
>>>>>>           Well the way I understand this proposal MFI is much weaker
>>>>>>           solution in terms of required separation.
>>>>>> 
>>>>>>           In contrast RFC8202 allows to separate ISIS instances at the
>>>>>>           process level, but here MFIs as defined must be handled by the
>>>>>>           same ISIS process
>>>>>> 
>>>>>>               This document defines an extension to
>>>>>>               IS-IS to allow*one standard instance*  of
>>>>>>               the protocol to support multiple update
>>>>>>               process operations.
>>>>>> 
>>>>>>           Thx,
>>>>>>           R.
>>>>>> 
>>>>>>           _______________________________________________
>>>>>>           Lsr mailing list
>>>>>>           Lsr@ietf.org <mailto:Lsr@ietf.org>
>>>>>>           https://www.ietf.org/mailman/listinfo/lsr
>>>>> 
>>>>>       _______________________________________________
>>>>>       Lsr mailing list
>>>>>       Lsr@ietf.org <mailto:Lsr@ietf.org>
>>>>>       https://www.ietf.org/mailman/listinfo/lsr
>>>>> 
>>>>> --
>>>>> 
>>>>> <http://www.verizon.com/>
>>>>> 
>>>>> *Gyan Mishra*
>>>>> 
>>>>> /Network Solutions A//rchitect /
>>>>> 
>>>>> /M 301 502-1347
>>>>> 13101 Columbia Pike
>>>>> /Silver Spring, MD
>>>>> 
>>>>> 
>>>> 
>>>> 
>>>> 
>>> 
>>> 
>>> 
>> 
>> 
>> 
>