IETF Last Call Review of draft-ietf-teep-protocol-21
review-ietf-teep-protocol-21-tsvart-lc-nishida-2025-10-13-00

This document has been reviewed as part of the transport area review team's
ongoing effort to review key IETF documents. These comments were written
primarily for the transport area directors, but are copied to the document's
authors and WG to allow them to address any issues raised and also to the IETF
discussion list for information.

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Summary: I think this document is on the right track, however it needs to clarify
         the several points related to transport protocols and error handlings
         schemes caused by lower layers to be published as a Standards Track document.
         The detailed points are listed below.

1: I think the document need to clarify whether specific transport protocols
   are required for TEEP or if transport is out-of-scope. If out-of-scope,
   reference companion specifications. Specify transport requirements such
   as reliability, ordered delivery, and connection characteristics.
  
2: What will happen when TEEP messages have been lost? I think the doc need 
   to descirbe error handling scheme such as the needs of timeout or 
   retransmission mechanism.

3: Similr to 2, what will happen when transport protocol fails in the middle of 
   transactions? Do we need to define recovery mechanism for such cases?

4: Is the protocol safe for idempotency? What if transport protocols or network layer 
   mistakenly send duplicated messages? I think fhe draft needs to specify behavior 
   some corner cases such as where an operation succeeds but the Success response is lost.

5: Should the token used in a TEEP message be globaly unique or just unique among 
   outstanding requests? The document needs to clarify the token lifetime and its reuse policy.

6: Should we use the same transport protocol for the connections beween TAM and 
   TEEP broker and the connection between TEEP broker and TEEP Agent?
   Should they have the same requirements for transport protocols or can 
   have different ones?

Thanks,
--
Yoshi