Re: [Idr] On the Calculation of Entropy Labels

Jeff Tantsura <> Mon, 15 March 2021 22:36 UTC

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Date: Mon, 15 Mar 2021 15:36:29 -0700
From: Jeff Tantsura <>
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Subject: Re: [Idr] On the Calculation of Entropy Labels
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Position of entropy label in SR stack is discussed in RFC8662

On Mar 15, 2021, 4:09 AM -0700,, wrote:
> Hi Robin,
> Thanks for your comments on draft-zhou-idr-bgp-srmpls-elp at the IDR meeting last week.
> You mentioned that there's a work about calculating both the vlaue and the position of the entropy labels using the controller.
> (Sorry I haven't find the draft, I would appreciate it if you could offer the name of the draft.)
> Since the entropy label value for each flow may be different, the control needs to calculate the value and the position of ELs per flow, and needs to maintain the state of the label stack per flow.
> The solution introduced in draft-zhou-idr-bgp-srmpls-elp is that the controller calculates the position of the ELs for each path. The method for calculating the EL value is unchanged, the ingress router computes a hash based on several fields from a given packet.
> The calculation and state in the controller is per path. This method is applicable to a network with many flows and ingress nodes.
> Regards,
> Yao
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