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

Tony Li <> Fri, 21 May 2021 15:28 UTC

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Date: Fri, 21 May 2021 08:28:38 -0700
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Cc: "Acee Lindem (acee)" <>, lsr <>,
To: Aijun Wang <>
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Subject: Re: [Lsr] LSR WG Adoption Poll for "Flexible Algorithms: Bandwidth, Delay, Metrics and Constraints" - draft-hegde-lsr-flex-algo-bw-con-02
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Hi Aijun,

> I support the adoption of the “FAD constraint sub-TLV” part(Section 3),  but not support the introduce of  “Bandwidth Metric Advertisement” part (Section 4) and other related parts.

As I understand it, we don’t get a line item veto, so I don’t know how the chairs will take this.

> With the introduce of additional constraint information, the problem described in “Introduction” part(Section 1) can be solved.

Please say more.  Claims without rationale are not reasoning.

> The usage of bandwidth metric in large network is not feasible. 


> And, would you like to explain more for the following statements(in Section
> “In the interface group mode, every node MUST identify the set of
>    parallel links between a pair of nodes based on IGP link
>    advertisements and MUST consider cumulative bandwidth of the parallel
>    links while arriving at the metric of each link.”
> based on example described in Figure 7? 

The paragraph immediately above explains exactly that. B->C has two parallel 10Gbps links, so it should be considered to be 20Gbps.

> How the cumulative bandwidth will be used to achieve the result that traffic from B to D will prefer B-C-F-D, not B-E-D? 

B-C-F-D is 20Gbps. B-E-D is 10Gbps.