Re: [Lsr] LSR WG Adoption Poll for "Flexible Algorithms: Bandwidth, Delay, Metrics and Constraints" - draft-hegde-lsr-flex-algo-bw-con-02

["Dongjie (Jimmy)" <[e-mail]>]

Thanks to Peter for his response to my third comment.

Could the authors also reply to the other comments (1, 2, 4) in the below mail? Many thanks.

Best regards,
Jie

From: Lsr [mailto:[e-mail]] On Behalf Of Dongjie (Jimmy)
Sent: Friday, May 14, 2021 3:52 PM
To: Acee Lindem (acee) <acee=[e-mail]>; [e-mail]
Cc: [e-mail]
Subject: Re: [Lsr] LSR WG Adoption Poll for "Flexible Algorithms: Bandwidth, Delay, Metrics and Constraints" - draft-hegde-lsr-flex-algo-bw-con-02

Hi authors,

I’ve read the latest version of this document and have the following comments:


1.       Is the generic metric type applicable to applications other than Flex-Algo? If so, it is better to make this clear in the document, or perhaps it may be defined separately from the Flex-Algo specific extensions?


2.       The “Exclude Minimum Bandwidth” constraint is compared with the maximum link bandwidth to exclude the links from the computation, it would be helpful if there is some analysis about how much this can help in traffic engineering, such as to reduce the congestion or improve the link utilization. One simple example is, if multiple Flex-Algos use this constraint to exclude the same set of links, this may increase the possibility of congestion on the rest of the links?



Perhaps a more general question is, what would be the benefit of introducing bandwidth attribute into Flex-Algo based distributed path computation?  It is known that bandwidth can be used in centralized computation for efficient path placement and resource management, can distributed computation with bandwidth constraint achieve the same, or is there some advantages compared with centralized computation?



3.       With the automatic metric calculation, it could introduce per Flex-Algo link metric value, while the existing Flex-Algo only refers to the metric of the link via metric type. Is this the expected behavior? Will it be further extended to make other link attributes flex-algo specific?



4.       In the reference bandwidth method, the draft says it simplifies the management in case the reference bandwidth needs to be changed. Since the reference bandwidth applies to the metric calculation of all the links in the flex-algo with the same proportion, it seems the change of the reference bandwidth will not impact the result of the path computation in the flex-algo. In which case the reference bandwidth need to be changed?

Best regards,
Jie

From: Lsr [mailto:[e-mail]] On Behalf Of Acee Lindem (acee)
Sent: Thursday, May 13, 2021 5:09 AM
To: [e-mail]<mailto:[e-mail]>
Cc: [e-mail]<mailto:[e-mail]>
Subject: [Lsr] LSR WG Adoption Poll for "Flexible Algorithms: Bandwidth, Delay, Metrics and Constraints" - draft-hegde-lsr-flex-algo-bw-con-02

Esteemed Members of the LSR WG,

This begins a 2 week WG adoption call for the following draft:

     https://datatracker.ietf.org/doc/draft-hegde-lsr-flex-algo-bw-con/

Please indicate your support or objection by May 27th, 2021.

Authors, please respond to the list indicating whether you are aware of any IPR that applies to this draft.

Thanks,
Chris and Acee