[Sidrops] draft-ietf-sidrops-8210bis-23 is ambiguous session mismatch handling

[Marco Marzetti <[e-mail]>]

Dear members of the SIDROPS WG,

I am working on a Python implementation of a RTR Cache, and I noticed some
ambiguity around how session mismatch should be handled.

At 5.1. (Fields of a PDU) the draft states that:
      If, at any time after the
      protocol version has been negotiated (Section 7), either the
      router or the cache finds that the value of the Session ID is not
      the same as the other's, the party which detects the mismatch MUST
      immediately terminate the session with an Error Report PDU with
      code 0 ("Corrupt Data"), and the router MUST flush all data
      learned from that cache.

While at 5.3. (Serial Query), the it states:
   The Session ID tells the cache what instance the router expects to
   ensure that the Serial Numbers are commensurate, i.e., the cache
   session has not been changed.  If the Session ID does not match, the
   cache MUST respond with a Cache Reset.


Does that mean that the Cache should send the Error Report PDU in all cases
but not in response to a Serial Query?

Thanks

-- 
Marco