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.html

You do have assure you don't create loops (e.g., do a feasible successor check 
as EIGRP does). 


Thanks,
Acee

> On Nov 4, 2025, at 11:46 PM, 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 10:49 AM 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]

Reply via email to