Hi All,
hank you for your valuable comments. To ensure we are fully aligned, we would like to further clarify the considerations behind our proposal. Please feel free to correct us if we have misunderstood any aspect of your suggestion. In designing our approach, we focused on addressing two key aspects: 1. **Parameter Consistency**: Parameters such as metric-step and metric-offset need to be consistent across the network. We observed that any inconsistency in static configuration could lead to incorrect normalized metrics, which might in turn affect path selection. 2. **Parameter Optimization**: In dynamic network environments, these parameters may need to be tuned. We think that relying solely on manual reconfiguration in such cases could not only be operationally costly and prone to errors, but also slow down routing convergence, potentially extending periods of network instability. These considerations motivated our proposal, which draws inspiration from the established concept of automatic metric calculation — an approach that addresses similar needs. We believe a protocol-based extension could be a suitable way to resolve these issues while staying consistent with existing mechanisms. We welcome further discussion. Best Regards, Liyan -----邮件原件-----发件人: Acee Lindem <[email protected]>发送时间: 2025年11月6日 3:06收件人: Gyan Mishra <[email protected]>抄送: Peter Psenak <[email protected]> [email protected]主题: [Lsr] Re: draft-gl-lsr-metric-normalize/Speaking as WG Member:Speaking as WG member, I agree with Peter as well.The additional alternative to local metric normalization is to do UCMP (Unequal Cost Mulltipath) route installation which is also a local behavior.Here is one example:https://www.cisco.com/c/en/us/td/docs/iosxr/ncs5500/routing/79x/b-routing-cg-ncs5500-79x/implementing-ucmp.htmlYou do have assure you don39t create loops (e.g., do a feasible successor check as EIGRP does).Thanks,Acee> On Nov 4, 2025, at 11:46PM, Gyan Mishra <[email protected]> wrote:>>> I agree with Peter that this draft is unnecessary.>> Delay metric normalization is common feature implemented by most all SR vendors to circumvent sub optimal undesired routing where ECMP exists or TI-LFA backup path is programmed. A single uS differential in ECMP links can break ECMP as well as TI-LFA.>> This is all local implementation specific and does not require any standardization.>>> Thanks>> Gyan>>>> On Tue, Nov 4, 2025 at 10:49AM Peter Psenak <[email protected]> wrote:> Hi,> here are my comments on the draft:> 1. Normalization of the measured latency, or any other PM related value, is a local behavior on the router. It should really be viewed as a part of the measurement procedure. The measured value is normalized before it is advertised.> 2. It is not functionally required for normalization to be used, nor for its logic/parameters to be synchronized across all routers in the network.> 3. Felx-algo definition (FAD) is not meant to be used as a management mechanism for distribution of the configuration parameters. There are exiting provisioning tools available for that.> To summarize, I find the proposals in the draft to be both unnecessary as well as undesirable.> thanks,> Peter>> _______________________________________________> Lsr mailing list -- [email protected]> To unsubscribe send an email to [email protected]> _______________________________________________> Lsr mailing list -- [email protected]> To unsubscribe send an email to [email protected]
_______________________________________________ Lsr mailing list -- [email protected] To unsubscribe send an email to [email protected]
