Hi Jie and WG,

While implementations may choose to assign Segment List IDs per Candidate Path 
for simplicity, the protocol should define the scope of the Segment List ID as 
unique within the headend node. This aligns with:
1.The logical resource model of SR Policy (RFC 9526), where all paths and 
segment lists are managed under a common headend context;
2.The operational requirement for concise, unambiguous referencing in 
telemetry, YANG, and fault correlation;
3.Future extensibility for shared segment lists.
Restricting the scope to Candidate Path would force management systems to carry 
full path context for every reference, negating the primary benefit of 
introducing the ID.


Best regards,
Guanming Zeng
Huawei
E-mail: [email protected]

From: Dongjie (Jimmy) <[email protected]>
Sent: Wednesday, February 11, 2026 6:31 PM
To: [email protected]
Cc: [email protected]; idr-chairs <[email protected]>; [email protected]
Subject: [spring] About the relationship between cadidate path and segment 
lists in SR Policy Architecture

Dear SPRING WG,

In a recent review of draft-ietf-idr-sr-policy-seglist-id-06 in IDR WG, I have 
one question about the scope of the segment list ID. It is further related to 
the relationship between candidate path and segment lists in the SR Policy 
Architecture.

As described in section 2.1 of this draft, the segment list ID is a 32-bit 
non-zero number that serves as the identifier associated with a segment list. 
And it says: the scope of this identifier is the SR Policy Candidate path.

I didn’t find the description about segment list ID and its scope in RFC 9526 
(SR Policy Architecture. Section 2.2 of RFC 9256 describes the relationship 
between candidate path and segment list, while it is not clear whether a 
segment list is bound to a candidate path, or it can be relocated to another 
candidate path without other change? If it is the latter case, it seems the 
segment list ID should not be scoped under a specific candidate path. Another 
related point is how a segment list should be identified/referenced in the 
control plane/management plane, does it require to use <candidate path ID + 
segment list ID>, or it can be referenced directly using the segment list ID? 
This could have impact on other protocol extensions related to the segment list.

After some discussion with the IDR chairs and Ketan, we think it is necessary 
to bring this to the SPRING WG and ask for your views and opinions.

Best regards,
Jie

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