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Proposal for Updates to Guidance on Packet Reordering#

IETF 124 (Montreal) digest Program Adjacent pick Montreal · 1–7 November 2025

Draft Session recording Materials

Greg White (CableLabs), Ingemar Johansson (Ericsson), Dibakar Das (Intel), Chris Box

  • Why: Several link-technology standards mandate in-order L2 delivery and implement resequencing buffers that add delay — exactly the machinery that defeats packet-spraying multipath in modern fabrics. Modern TCP and QUIC tolerate reordering far better than the L2 standards bodies assume.
  • What: Informational guidance for layer-2 standards organizations: IETF transport protocols do not require guaranteed in-order delivery, so the resequencing requirement can be relaxed where it causes net performance degradation (from abstract only).
  • How: Cites the modern TCP/QUIC features that improve out-of-order tolerance as the basis for updating the guidance L2 standards cite.
  • Where applicable: Link-technology standards (link aggregation, L2 transport) — general technique, not org-specific. Maturity signal worth noting: since the meeting, the individual draft was adopted by INTAREA and replaced by WG document draft-ietf-intarea-reordering, so consensus is forming.