Gyan,
On 05/03/2021 16:46, Gyan Mishra wrote:
Yali
I agree with a Peter.
As for resource isolation and provisioning of a VTN I think you really
need separate LSDB instances provided by MT or MI as better suited for
network slicing.
MT does not provide LSDB separation, only MI does.
thanks,
Peter
To me it seems a common LSDB shared among network slices VTN underlay
could be problematic with network overlap issues.
Kind Regards
Gyan
On Fri, Mar 5, 2021 at 10:28 AM Peter Psenak <ppse...@cisco.com
<mailto:ppse...@cisco.com>> wrote:
Hi Yali,
On 05/03/2021 15:31, wangyali wrote:
> Hi Peter,
>
> Thanks for your question. Please see inline [yali3].
>
> -----Original Message-----
> From: Peter Psenak [mailto:ppse...@cisco.com
<mailto:ppse...@cisco.com>]
> Sent: Thursday, March 4, 2021 11:20 PM
> To: wangyali <wangyal...@huawei.com
<mailto:wangyal...@huawei.com>>; Gyan Mishra <hayabusa...@gmail.com
<mailto:hayabusa...@gmail.com>>; Robert Raszuk <rob...@raszuk.net
<mailto:rob...@raszuk.net>>
> Cc: Huzhibo <huzh...@huawei.com <mailto:huzh...@huawei.com>>;
Aijun Wang <wang...@chinatelecom.cn
<mailto:wang...@chinatelecom.cn>>; Tony Li <tony...@tony.li
<mailto:tony...@tony.li>>; lsr <lsr@ietf.org <mailto:lsr@ietf.org>>;
Tianran Zhou <zhoutian...@huawei.com <mailto:zhoutian...@huawei.com>>
> Subject: Re: [Lsr] New Version Notification for
draft-wang-lsr-isis-mfi-00.txt
>
> Hi Yali,
>
> On 04/03/2021 14:45, wangyali wrote:
>> Hi Peter,
>>
>> Please see inline [Yali2]. Thanks a lot.
>>
>> -----Original Message-----
>> From: Peter Psenak [mailto:ppse...@cisco.com
<mailto:ppse...@cisco.com>]
>> Sent: Thursday, March 4, 2021 6:50 PM
>> To: wangyali <wangyal...@huawei.com
<mailto:wangyal...@huawei.com>>; Gyan Mishra
>> <hayabusa...@gmail.com <mailto:hayabusa...@gmail.com>>; Robert
Raszuk <rob...@raszuk.net <mailto:rob...@raszuk.net>>
>> Cc: Huzhibo <huzh...@huawei.com <mailto:huzh...@huawei.com>>;
Aijun Wang
>> <wang...@chinatelecom.cn <mailto:wang...@chinatelecom.cn>>; Tony
Li <tony...@tony.li <mailto:tony...@tony.li>>; lsr
>> <lsr@ietf.org <mailto:lsr@ietf.org>>; Tianran Zhou
<zhoutian...@huawei.com <mailto:zhoutian...@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:ppse...@cisco.com
<mailto:ppse...@cisco.com>]
>>> Sent: Wednesday, March 3, 2021 5:37 PM
>>> To: wangyali <wangyal...@huawei.com
<mailto:wangyal...@huawei.com>>; Gyan Mishra
>>> <hayabusa...@gmail.com <mailto:hayabusa...@gmail.com>>; Robert
Raszuk <rob...@raszuk.net <mailto:rob...@raszuk.net>>
>>> Cc: Huzhibo <huzh...@huawei.com <mailto:huzh...@huawei.com>>;
Aijun Wang
>>> <wang...@chinatelecom.cn <mailto:wang...@chinatelecom.cn>>;
Tony Li <tony...@tony.li <mailto:tony...@tony.li>>; lsr
>>> <lsr@ietf.org <mailto:lsr@ietf.org>>; Tianran Zhou
<zhoutian...@huawei.com <mailto:zhoutian...@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.
>
>
> it's not the name that is as important. It's the concept that
looks questionable - how well can you isolate the update processing
if the data are part of the same LSDB and whether such update
process separation would prove to be useful at all. I don't know, so
far I have not seen any evidence.
> [yali3] This draft defines a new TLV, i.e. MFI-ID TLV, which may
be included in each Level 1/Level 2 IS-IS LSPs and SNPs. Hence, each
Level 1/Level 2 LSPs and SNPs associated with each Update Process
can be uniquely identified by MFI-ID.
> In this draft, each flooding instance has its own separated
Update process, which isolates the impact of application information
flooding on the IS-IS protocol operation. So each Level 1/Level 2
LSP associated with a specific MFI carries flooding information
belonging to the specific MFI. And Level 1/Level 2 PSNP and Level
1/Level 2 CSNP containing information about LSPs that propagated in
the specific MFI are generated to synchronize the MFI-specific LSDB.
- by using the same LSDB to store the MFI specific information only a
limited separation can be achieved. Multi-instance gives you better
separation.
- you carved the MFI specific LSP space from the common LSP space. This
may result in the non routing apps consuming the space that would
otherwise be required for regular routing information, compromising the
basic functionality of the protocol. Multi-instance does not have that
problem.
my 2c,
Peter
>
> thanks,
> Peter
>
>
>
>
>>
>> thanks,
>> Peter
>>
>>>
>>> thanks,
>>> Peter
>>>
>>>
>>>>
>>>> Best,
>>>> Yali
>>>>
>>>> -----Original Message-----
>>>> From: Peter Psenak [mailto:ppse...@cisco.com
<mailto:ppse...@cisco.com>]
>>>> Sent: Tuesday, March 2, 2021 5:12 PM
>>>> To: wangyali <wangyal...@huawei.com
<mailto:wangyal...@huawei.com>>; Gyan Mishra
>>>> <hayabusa...@gmail.com <mailto:hayabusa...@gmail.com>>; Robert
Raszuk <rob...@raszuk.net <mailto:rob...@raszuk.net>>
>>>> Cc: Huzhibo <huzh...@huawei.com <mailto:huzh...@huawei.com>>;
Aijun Wang
>>>> <wang...@chinatelecom.cn <mailto:wang...@chinatelecom.cn>>;
Tony Li <tony...@tony.li <mailto:tony...@tony.li>>; lsr
>>>> <lsr@ietf.org <mailto:lsr@ietf.org>>; Tianran Zhou
<zhoutian...@huawei.com <mailto:zhoutian...@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:ppse...@cisco.com
<mailto:ppse...@cisco.com>]
>>>>> Sent: Sunday, February 28, 2021 8:23 PM
>>>>> To: Gyan Mishra <hayabusa...@gmail.com
<mailto:hayabusa...@gmail.com>>; Robert Raszuk
>>>>> <rob...@raszuk.net <mailto:rob...@raszuk.net>>
>>>>> Cc: Huzhibo <huzh...@huawei.com <mailto:huzh...@huawei.com>>;
Aijun Wang
>>>>> <wang...@chinatelecom.cn <mailto:wang...@chinatelecom.cn>>;
Tony Li <tony...@tony.li <mailto:tony...@tony.li>>; lsr
>>>>> <lsr@ietf.org <mailto:lsr@ietf.org>>; Tianran Zhou
<zhoutian...@huawei.com <mailto:zhoutian...@huawei.com>>; wangyali
>>>>> <wangyal...@huawei.com <mailto:wangyal...@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
<rob...@raszuk.net <mailto:rob...@raszuk.net>
>>>>>> <mailto:rob...@raszuk.net <mailto:rob...@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
<wang...@chinatelecom.cn <mailto:wang...@chinatelecom.cn>
>>>>>> <mailto:wang...@chinatelecom.cn
<mailto:wang...@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
<rob...@raszuk.net <mailto:rob...@raszuk.net>
>>>>>>> <mailto:rob...@raszuk.net
<mailto:rob...@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
<https://www.google.com/maps/search/lution+we+recommend?entry=gmail&source=g>
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> <mailto:Lsr@ietf.org
<mailto:Lsr@ietf.org>>
>>>>>>> https://www.ietf.org/mailman/listinfo/lsr
>>>>>>
>>>>>> _______________________________________________
>>>>>> Lsr mailing list
>>>>>> Lsr@ietf.org <mailto:Lsr@ietf.org> <mailto: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
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>>
>>
>
>
>
--
<http://www.verizon.com/>
*Gyan Mishra*
/Network Solutions A//rchitect /
/M 301 502-1347
13101 Columbia Pike
/Silver Spring, MD
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