Dear TEAS WG chairs and the WG

There was a fork of this thread to limit to MPLS WG (for a good reason). 
Connecting back to the comment relevant to TEAS. 

I am not concerned about NRPS space on the control-plane side or its mapping to 
the data-plane.
However, I am concerned about data plane mapping across different data planes 
(interworking).
My concern is that earlier poll on this was very weakly participated (as 
acknowledged in one of the TEAS sessions)

Why is 20-bit NRPS not enough across all data planes?

Thanks

Regards … Zafar 



On 12/3/25, 10:09 AM, "Zafar Ali (zali)" <[email protected] 
<mailto:[email protected]>> wrote:


Hi


I agree with Jie that " it would be better to have the same number of bits in 
the forwarding plane and in the control plane, which could make the mapping 
much easier".
Keep length consistent between MPLS and SRv6 is also good as it makes mapping 
easier.


I also believe that "a smaller" numbers of NRPs are required as each NRP 
represent an instance in management plane and hardware scale prohibits 
supporting larger numbers of NRP.
I do not see any reason why a 20-bit NRP Selector would not suffice, across all 
data planes.


Thanks


Regards … Zafar




On 12/1/25, 7:56 AM, "Dongjie (Jimmy)" <[email protected] 
<mailto:[email protected]> <mailto:[email protected] 
<mailto:[email protected]>>> wrote:




Hi Adrian,




I thought I have replied to this mail, apparently I didn't press the send 
button.




Regarding the length of the NRP Selector ID, I agree it would be better to have 
the same number of bits in the forwarding plane and in the control plane, which 
could make the mapping much easier.




IMO the decision made by TEAS of allowing different length of the ID 
acknowledged the difference in data plane protocols, which makes sense. 
Protocols like MPLS may have limitation in encoding, and may not be required to 
provide the same scalability as IPv6/SRv6 does.




If the length of NRP Selector ID in MPLS and SRv6 domain are different, mapping 
can be performed at the boundaries. Actually even if the length are the same, 
mapping of the ID value at domain boundaries may still be needed.




That said, it would be good if there can be one option in which they have the 
same length, preferably it is also the same as the ID length in the control 
plane.




Best regards,
Jie






Cisco Confidential
-----Original Message-----
From: Adrian Farrel <[email protected] <mailto:[email protected]> 
<mailto:[email protected] <mailto:[email protected]>>>
Sent: Monday, November 17, 2025 12:23 AM
To: 'TEAS WG' <[email protected] <mailto:[email protected]> <mailto:[email protected] 
<mailto:[email protected]>>>; [email protected] <mailto:[email protected]> 
<mailto:[email protected] <mailto:[email protected]>>; [email protected] 
<mailto:[email protected]> <mailto:[email protected] <mailto:[email protected]>>
Cc: 'mpls' <[email protected] <mailto:[email protected]> <mailto:[email protected] 
<mailto:[email protected]>>>
Subject: [spring] MPLS WGLC on draft-ietf-mpls-mna-nrp-selector




Please note that the MPLS working group is holding a last call on 
draft-ietf-mpls-mna-nrp-selector. I am the document shepherd.




There are issues around the size of the NRP Selector / identifier that may be 
of relevance to TEAS, 6MAN, and SPRING. I'd appreciate it if any discussions 
could take place on the MPLS list so that it is easier to coordinate.




The questions are:




1. How many bits are needed to encode the NRP Selector in the MPLS forwarding 
plane?
It has been suggested that it is important to allow the same number of bits in 
the forwarding plane as are available in the control plane.
It has also been pointed out that it is always possible to map between the 
control plane representation and the forwarding plane representation, and it is 
possible to limit the expression of the identifier in the control plane such 
that it is suitable for a particular data plane.
Here, the opinion of TEAS may be helpful to us.




2. Should the encoding of the NRP Selector in the MPLS and SRv6 forwarding 
planes be identical?
It has been suggested that in multi-technology-domain scenarios, it would be 
helpful to have the same NRP Selector values in each domain. This could make 
management and debugging simpler.
It has been pointed out that if the sizes of NRP Selector are different in the 
two domains, the smaller can be used as a subset of the larger, to enable 
multi-domain operation, or that mapping can be performed at the domain 
boundaries.
This question is particularly relevant to 6MAN and SPRING.




Thanks for any thoughts.




Adrian




























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