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IETF RFC 9956
[ACTIVE]

A Non-Queue-Building Per-Hop Behavior (NQB PHB) for Differentiated Services

Metadata

Publisher
IETF
Doc Type
Standard
Pages
32
Abstract
This document specifies characteristics of a Non-Queue-Building Per-Hop Behavior (NQB PHB). The NQB PHB provides a shallow-buffered, best-effort service as a complement to a Default deep-buffered, best-effort service for Internet services. The purpose of this NQB PHB is to provide a separate queue that enables smooth (i.e., non-bursty), low-data-rate, application-limited traffic microflows, to avoid the delay, delay variation and loss that would ordinarily be caused by sharing a queue with bursty, capacity-seeking traffic. This PHB is implemented without prioritization and can be implemented without rate policing, making it suitable for environments where the use of these features is restricted. The NQB PHB has been developed primarily for use by access network segments, where queuing delay and queuing loss caused by Queue-Building (QB) protocols are manifested; however, its use is not limited to such segments. In particular, the application of NQB PHB to cable broadband links, Wi-Fi links, and mobile network radio/core segments are discussed in this document. This document recommends a specific Differentiated Services Code Point (DSCP) to identify NQB microflows and updates the guidance in RFC 8325 on mapping Differentiated Services (Diffserv or DS) to IEEE 802.11 for this codepoint.
Publication Date
2026-05-01
Status Note
Proposed Standard
DOI
10.17487/RFC9956
Link
https://doi.org/10.17487/RFC9956
Author(s)
Greg White
Thomas Fossati
Ruediger Geib
Keyword(s)
DiffServ, DSCP, L4S, Latency, Jitter, Delay Variation, Queuing Variation, One-way Delay, RTT, Quality Of Service, QoS, Quality of Experience, QoE
Latest version of IETF RFC 9956

Document Versions — IETF RFC 9956

  • ▶ IETF RFC 9956 (2026-05-01)
    THIS DOC [ACTIVE] [LATEST VERSION]

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Amends:
IETF RFC 8325 [Active*]

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IETF RFC 9956, A Non-Queue-Building Per-Hop Behavior (NQB PHB) for Differentiated Services. Available at https://doi.org/10.17487/RFC9956
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IETF RFC 9956, A Non-Queue-Building Per-Hop Behavior (NQB PHB) for Differentiated Services. Available at https://doi.org/10.17487/RFC9956

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IETF RFC 9956, A Non-Queue-Building Per-Hop Behavior (NQB PHB) for Differentiated Services. Available at https://doi.org/10.17487/RFC9956
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<span class="citation"><cite>IETF RFC 9956</cite>, A Non-Queue-Building Per-Hop Behavior (NQB PHB) for Differentiated Services. Available at <a href="https://doi.org/10.17487/RFC9956" target="_blank" rel="noopener">https://doi.org/10.17487/RFC9956</a></span>

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Preview:
IETF RFC 9956, A Non-Queue-Building Per-Hop Behavior (NQB PHB) for Differentiated Services
doi: 10.17487/RFC9956
url: https://doi.org/10.17487/RFC9956
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<li>
<cite id="bib-rfc9956">IETF RFC 9956</cite>, A Non-Queue-Building Per-Hop Behavior (NQB PHB) for Differentiated Services
<span class="doi">10.17487/RFC9956</span>
</li>

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