{"draft":"draft-ietf-tsvwg-nqb-33","doc_id":"RFC9956","title":"A Non-Queue-Building Per-Hop Behavior (NQB PHB) for Differentiated Services","authors":["G. White","T. Fossati","R. Geib"],"format":["HTML","TEXT","PDF","XML"],"page_count":"32","pub_status":"PROPOSED STANDARD","status":"PROPOSED STANDARD","source":"Transport and Services Working Group","abstract":"This document specifies characteristics of a Non-Queue-Building\r\nPer-Hop Behavior (NQB PHB). The NQB PHB provides a shallow-buffered,\r\nbest-effort service as a complement to a Default deep-buffered,\r\nbest-effort service for Internet services.  The purpose of this NQB\r\nPHB is to provide a separate queue that enables smooth (i.e.,\r\nnon-bursty), low-data-rate, application-limited traffic microflows,\r\nto avoid the delay, delay variation and loss that would ordinarily be\r\ncaused by sharing a queue with bursty, capacity-seeking traffic. \r\nThis PHB is implemented without prioritization and can be implemented\r\nwithout rate policing, making it suitable for environments where the\r\nuse of these features is restricted. The NQB PHB has been developed\r\nprimarily for use by access network segments, where queuing delay and\r\nqueuing loss caused by Queue-Building (QB) protocols are manifested;\r\nhowever, its use is not limited to such segments. In particular, the\r\napplication of NQB PHB to cable broadband links, Wi-Fi links, and\r\nmobile network radio\/core segments are discussed in this document.\r\nThis document recommends a specific Differentiated Services Code\r\nPoint (DSCP) to identify NQB microflows and updates the guidance in\r\nRFC 8325 on mapping Differentiated Services (Diffserv or DS) to IEEE\r\n802.11 for this codepoint.","pub_date":"May 2026","keywords":["DS","DSCP","L4S","delay","jitter","delay variation","Queuing variation","One Way Delay","Round-Trip Time","RTT","Quality of Service","QoS","Quality of Experience","QoE"],"obsoletes":[],"obsoleted_by":[],"updates":["RFC8325"],"updated_by":[],"see_also":[],"doi":"10.17487\/RFC9956","errata_url":null}