Diffserv

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.

This document defines a new Data Item for the Dynamic Link Exchange Protocol (DLEP) to support traffic classification. Traffic classification information identifies traffic flows based on frame/packet content such as a destination address. The Data Item is defined in an extensible and reusable fashion. Its use will be mandated in other documents defining specific DLEP extensions. This document also introduces DLEP Sub-Data Items and defines two new Sub-Data Items to support Diffserv and Ethernet traffic classification.

This document defines an extension to the Dynamic Link Exchange Protocol (DLEP) that enables a Diffserv aware credit window scheme for destination-specific and shared flow control.

This document discusses considerations for assigning a new recommended Differentiated Services Code Point (DSCP) for a standard Per-Hop Behavior (PHB). It considers the common observed re-marking behaviors that the Diffserv field might be subjected to along an Internet path. It also notes some implications of using a specific DSCP.

This specification presents an optional method to add integrity protection directly to the Network Service Header (NSH) used for Service Function Chaining (SFC). Also, this specification allows for the encryption of sensitive metadata (MD) that is carried in the NSH.

Networks can provide different forwarding treatments for individual packets based on Differentiated Services Code Point (DSCP) values on a per-hop basis. This document provides the recommended DSCP values for web browsers to use for various classes of Web Real-Time Communication (WebRTC) traffic.

This document specifies properties and characteristics of a Lower- Effort Per-Hop Behavior (LE PHB). The primary objective of this LE PHB is to protect Best-Effort (BE) traffic (packets forwarded with the default PHB) from LE traffic in congestion situations, i.e., when resources become scarce, BE traffic has precedence over LE traffic and may preempt it. Alternatively, packets forwarded by the LE PHB can be associated with a scavenger service class, i.e., they scavenge otherwise-unused resources only. There are numerous uses for this PHB, e.g., for background traffic of low precedence, such as bulk data transfers with low priority in time, non-time-critical backups, larger software updates, web search engines while gathering information from web servers and so on. This document recommends a standard Differentiated Services Code Point (DSCP) value for the LE PHB.

This specification obsoletes RFC 3662 and updates the DSCP recommended in RFCs 4594 and 8325 to use the DSCP assigned in this specification.

Hierarchical Service Function Chaining (hSFC) is a network architecture allowing an organization to decompose a large-scale network into multiple domains of administration.

The goals of hSFC are to make a large-scale network easier to design, simpler to control, and supportive of independent functional groups within large network operators.

The Differentiated Services (Diffserv) architecture specifies use of the DS field in the IPv4 and IPv6 packet headers to carry one of 64 distinct differentiated services field codepoint (DSCP) values. The Internet Assigned Numbers Authority (IANA) maintains a registry of assigned DSCP values.

This update to RFC 2474 changes the IANA registration policy for Pool 3 of the registry (i.e., DSCP values of the form xxxx01) to Standards Action, i.e., values are assigned through a Standards Track or Best Current Practice RFC. The update also removes permission for experimental and local use of the codepoints that form Pool 3 of the DSCP registry; Pool 2 Codepoints (i.e., DSCP values of the form xxxx11) remain available for these purposes.

As Internet traffic is increasingly sourced from and destined to wireless endpoints, it is crucial that Quality of Service (QoS) be aligned between wired and wireless networks; however, this is not always the case by default. This document specifies a set of mappings from Differentiated Services Code Point (DSCP) to IEEE 802.11 User Priority (UP) to reconcile the marking recommendations offered by the IETF and the IEEE so as to maintain consistent QoS treatment between wired and IEEE 802.11 wireless networks.

This document defines a limited common set of Diffserv Per-Hop Behaviors (PHBs) and Diffserv Codepoints (DSCPs) to be applied at (inter)connections of two separately administered and operated networks, and it explains how this approach can simplify network configuration and operation. Many network providers operate Multiprotocol Label Switching (MPLS) using Treatment Aggregates for traffic marked with different Diffserv Per-Hop Behaviors and use MPLS for interconnection with other networks. This document offers a simple interconnection approach that may simplify operation of Diffserv for network interconnection among providers that use MPLS and apply the Short Pipe Model. While motivated by the requirements of MPLS network operators that use Short Pipe Model tunnels, this document is applicable to other networks, both MPLS and non-MPLS.

This memo describes the interaction between Differentiated Services (Diffserv) network quality-of-service (QoS) functionality and real- time network communication, including communication based on the Real-time Transport Protocol (RTP). Diffserv is based on network nodes applying different forwarding treatments to packets whose IP headers are marked with different Diffserv Codepoints (DSCPs). WebRTC applications, as well as some conferencing applications, have begun using the Session Description Protocol (SDP) bundle negotiation mechanism to send multiple traffic streams with different QoS requirements using the same network 5-tuple. The results of using multiple DSCPs to obtain different QoS treatments within a single network 5-tuple have transport protocol interactions, particularly with congestion control functionality (e.g., reordering). In addition, DSCP markings may be changed or removed between the traffic source and destination. This memo covers the implications of these Diffserv aspects for real-time network communication, including WebRTC.

The objective of Pre-Congestion Notification (PCN) is to protect the quality of service (QoS) of inelastic flows within a Diffserv domain. The overall rate of PCN-traffic is metered on every link in the PCN- domain, and PCN-packets are appropriately marked when certain configured rates are exceeded. Egress nodes pass information about these PCN-marks to Decision Points that then decide whether to admit or block new flow requests or to terminate some already admitted flows during serious pre-congestion.

This document specifies how PCN-marks are to be encoded into the IP header by reusing the Explicit Congestion Notification (ECN) codepoints within a PCN-domain. The PCN wire protocol for non-IP protocol headers will need to be defined elsewhere. Nonetheless, this document clarifies the PCN encoding for MPLS in an informational appendix. The encoding for IP provides for up to three different PCN marking states using a single Diffserv codepoint (DSCP): not-marked (NM), threshold-marked (ThM), and excess-traffic-marked (ETM). Hence, it is called the 3-in-1 PCN encoding. This document obsoletes RFC 5696. [STANDARDS-TRACK]

Pre-Congestion Notification (PCN) is a means for protecting quality of service for inelastic traffic admitted to a Diffserv domain. The overall PCN architecture is described in RFC 5559. This memo describes the requirements for the signaling applied within the PCN-domain: (1) PCN-feedback-information is carried from the PCN-egress-node to the Decision Point; (2) the Decision Point may ask the PCN-ingress-node to measure, and report back, the rate of sent PCN-traffic between that PCN-ingress-node and PCN-egress-node. The Decision Point may be either collocated with the PCN-ingress-node or a centralized node (in the first case, (2) is not required). The signaling requirements pertain in particular to two edge behaviors, Controlled Load (CL) and Single Marking (SM). This document is not an Internet Standards Track specification; it is published for informational purposes.

This document describes a Next Steps in Signaling (NSIS) Quality-of-Service (QoS) Model for networks that use the Resource Management in Diffserv (RMD) concept. RMD is a technique for adding admission control and preemption function to Differentiated Services (Diffserv) networks. The RMD QoS Model allows devices external to the RMD network to signal reservation requests to Edge nodes in the RMD network. The RMD Ingress Edge nodes classify the incoming flows into traffic classes and signals resource requests for the corresponding traffic class along the data path to the Egress Edge nodes for each flow. Egress nodes reconstitute the original requests and continue forwarding them along the data path towards the final destination. In addition, RMD defines notification functions to indicate overload situations within the domain to the Edge nodes. This document defines an Experimental Protocol for the Internet community.

This document requests one Differentiated Services Code Point (DSCP) from the Internet Assigned Numbers Authority (IANA) for a class of real-time traffic. This traffic class conforms to the Expedited Forwarding Per-Hop Behavior. This traffic is also admitted by the network using a Call Admission Control (CAC) procedure involving authentication, authorization, and capacity admission. This differs from a real-time traffic class that conforms to the Expedited Forwarding Per-Hop Behavior but is not subject to capacity admission or subject to very coarse capacity admission. [STANDARDS-TRACK]

This document describes a general architecture for flow admission and termination based on pre-congestion information in order to protect the quality of service of established, inelastic flows within a single Diffserv domain. This memo provides information for the Internet community.

This document specifies a CLASSTYPE object to support Diffserv-Aware Traffic Engineering (DS-TE) where path computation is performed with the aid of a Path Computation Element (PCE). [STANDARDS-TRACK]

This memo analyzes provider-to-provider Quality of Service (QoS) agreements suitable for a global QoS-enabled Internet. It defines terminology relevant to inter-domain QoS models. It proposes a new concept denoted by Meta-QoS-Class (MQC). This concept could potentially drive and federate the way QoS inter-domain relationships are built between providers. It opens up new perspectives for a QoS- enabled Internet that retains, as much as possible, the openness of the existing best-effort Internet. This memo provides information for the Internet community.

In the core of a high-capacity network, service differentiation may still be needed to support applications' utilization of the network. Applications with similar traffic characteristics and performance requirements are mapped into Diffserv service classes based on end- to-end behavior requirements of the applications. However, some network segments may be configured in such a way that a single forwarding treatment may satisfy the traffic characteristics and performance requirements of two or more service classes. In these cases, it may be desirable to aggregate two or more Diffserv service classes into a single forwarding treatment. This document provides guidelines for the aggregation of Diffserv service classes into forwarding treatments. This memo provides information for the Internet community.

RFC 3270 defines how to support the Diffserv architecture in MPLS networks, including how to encode Diffserv Code Points (DSCPs) in an MPLS header. DSCPs may be encoded in the EXP field, while other uses of that field are not precluded. RFC 3270 makes no statement about how Explicit Congestion Notification (ECN) marking might be encoded in the MPLS header. This document defines how an operator might define some of the EXP codepoints for explicit congestion notification, without precluding other uses. [STANDARDS-TRACK]

RFC 3175 specifies aggregation of Resource ReSerVation Protocol (RSVP) end-to-end reservations over aggregate RSVP reservations. This document specifies aggregation of RSVP end-to-end reservations over MPLS Traffic Engineering (TE) tunnels or MPLS Diffserv-aware MPLS Traffic Engineering (DS-TE) tunnels. This approach is based on RFC 3175 and simply modifies the corresponding procedures for operations over MPLS TE tunnels instead of aggregate RSVP reservations. This approach can be used to achieve admission control of a very large number of flows in a scalable manner since the devices in the core of the network are unaware of the end-to-end RSVP reservations and are only aware of the MPLS TE tunnels. [STANDARDS-TRACK]

This document describes service classes configured with Diffserv and recommends how they can be used and how to construct them using Differentiated Services Code Points (DSCPs), traffic conditioners, Per-Hop Behaviors (PHBs), and Active Queue Management (AQM) mechanisms. There is no intrinsic requirement that particular DSCPs, traffic conditioners, PHBs, and AQM be used for a certain service class, but as a policy and for interoperability it is useful to apply them consistently. This memo provides information for the Internet community.

This document describes a two-rate, three-color marker that has been in use for data services including Frame Relay services. This marker can be used for metering per-flow traffic in the emerging IP and L2 VPN services. The marker defined here is different from previously defined markers in the handling of the in-profile traffic. Furthermore, this marker doesn't impose peak-rate shaping requirements on customer edge (CE) devices. This memo provides information for the Internet community.

This document specifies the protocol extensions for support of Diffserv-aware MPLS Traffic Engineering (DS-TE). This includes generalization of the semantics of a number of Interior Gateway Protocol (IGP) extensions already defined for existing MPLS Traffic Engineering in RFC 3630, RFC 3784, and additional IGP extensions beyond those. This also includes extensions to RSVP-TE signaling beyond those already specified in RFC 3209 for existing MPLS Traffic Engineering. These extensions address the requirements for DS-TE spelled out in RFC 3564. [STANDARDS-TRACK]

This document provides specifications for one Bandwidth Constraints Model for Diffserv-aware MPLS Traffic Engineering, which is referred to as the Maximum Allocation Model. This memo defines an Experimental Protocol for the Internet community.

This document complements the Diffserv-aware MPLS Traffic Engineering (DS-TE) requirements document by giving a functional specification for the Maximum Allocation with Reservation (MAR) Bandwidth Constraints Model. Assumptions, applicability, and examples of the operation of the MAR Bandwidth Constraints Model are presented. MAR performance is analyzed relative to the criteria for selecting a Bandwidth Constraints Model, in order to provide guidance to user implementation of the model in their networks. This memo defines an Experimental Protocol for the Internet community.

This document provides specifications for one Bandwidth Constraints Model for Diffserv-aware MPLS Traffic Engineering, which is referred to as the Russian Dolls Model. This memo defines an Experimental Protocol for the Internet community.

"Differentiated Services (Diffserv)-aware MPLS Traffic Engineering Requirements", RFC 3564, specifies the requirements and selection criteria for Bandwidth Constraints Models. Two such models, the Maximum Allocation and the Russian Dolls, are described therein. This document complements RFC 3564 by presenting the results of a performance evaluation of these two models under various operational conditions: normal load, overload, preemption fully or partially enabled, pure blocking, or complete sharing. This memo provides information for the Internet community.

This document discusses the problems of IP Multicast use in Differentiated Services (DS) networks, expanding on the discussion in RFC 2475 ("An Architecture of Differentiated Services"). It also suggests possible solutions to these problems, describes a potential implementation model, and presents simulation results. This memo provides information for the Internet community.

This memo describes a MIB module that provides a conceptual layer between high-level "network-wide" policy definitions that effect configuration of the Differentiated Services (diffserv) subsystem and the instance-specific information that would include such details as the parameters for all the queues associated with each interface in a system. This essentially provides an interface for configuring differentiated services at a conceptually higher layer than that of the Differentiated Services MIB. [PROPOSED STANDARD]

This document presents Service Provider requirements for support of Differentiated Services (Diff-Serv)-aware MPLS Traffic Engineering (DS- TE). Its objective is to provide guidance for the definition, selection and specification of a technical solution addressing these requirements. Specification for this solution itself is outside the scope of this document. A problem statement is first provided. Then, the document describes example applications scenarios identified by Service Providers where existing MPLS Traffic Engineering mechanisms fall short and Diff-Serv-aware Traffic Engineering can address the needs. The detailed requirements that need to be addressed by the technical solution are also reviewed. Finally, the document identifies the evaluation criteria that should be considered for selection and definition of the technical solution. This memo provides information for the Internet community.

This document specifies a Resource ReSerVation Protocol-Traffic Engineering (RSVP-TE) signaling extension for support of Asynchronous Transfer Mode (ATM) Service Class-aware Multiprotocol Label Switching (MPLS) Traffic Engineering. This memo provides information for the Internet community.

This document describes a Policy Information Base (PIB) for a device

implementing the Differentiated Services Architecture. The

provisioning classes defined here provide policy control of

resources implementing the Differentiated Services Architecture.

These provisioning classes can be used with other none

Differentiated Services provisioning classes (defined in other PIBs)

to provide for a comprehensive policy controlled mapping of service

requirement to device resource capability and usage.

The Layer Two Tunneling Protocol (L2TP) provides a standard method

for tunneling PPP packets. The current specification provides no

provisions for supporting Differentiated Services (diffserv) over the

L2TP control connection or subsequent data sessions. As a result, no

standard mechanism currently exists within L2TP to provide L2TP

protocol negotiations for service discrimination.

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects used for monitoring Differentiated Services (DS) Codepoint usage in packets which contain a DS field, utilizing the monitoring framework defined in the RMON-2 (Remote Network Monitoring Management Version 2) MIB. [STANDARDS-TRACK]

This memo describes an SMIv2 (Structure of Management Information version 2) MIB for a device implementing the Differentiated Services Architecture. It may be used both for monitoring and configuration of a router or switch capable of Differentiated Services functionality. [STANDARDS-TRACK]

This document proposes an informal management model of Differentiated Services (Diffserv) routers for use in their management and configuration. This model defines functional datapath elements (e.g., classifiers, meters, actions, marking, absolute dropping, counting, multiplexing), algorithmic droppers, queues and schedulers. It describes possible configuration parameters for these elements and how they might be interconnected to realize the range of traffic conditioning and per-hop behavior (PHB) functionalities described in the Diffserv Architecture. This memo provides information for the Internet community.

This document defines a flexible solution for support of Differentiated Services (Diff-Serv) over Multi-Protocol Label Switching (MPLS) networks. [STANDARDS-TRACK]

This memo captures Diffserv working group agreements concerning new and improved terminology, and provides minor technical clarifications. It is intended to update RFC 2474, RFC 2475 and RFC 2597. When RFCs 2474 and 2597 advance on the standards track, and RFC 2475 is updated, it is intended that the revisions in this memo will be incorporated, and that this memo will be obsoleted by the new RFCs. This memo provides information for the Internet community.

This document defines a PHB (per-hop behavior) called Expedited Forwarding (EF). The PHB is a basic building block in the Differentiated Services architecture. EF is intended to provide a building block for low delay, low jitter and low loss services by ensuring that the EF aggregate is served at a certain configured rate. This document obsoletes RFC 2598. [STANDARDS-TRACK]

This document was written during the process of clarification of RFC2598 "An Expedited Forwarding PHB" that led to the publication of revised specification of EF "An Expedited Forwarding PHB". Its primary motivation is providing additional explanation to the revised EF definition and its properties. The document also provides additional implementation examples and gives some guidance for computation of the numerical parameters of the new definition for several well known schedulers and router architectures. This memo provides information for the Internet community.

For historical interest, this document captures the EF Design Team's proposed solution, preferred by the original authors of RFC 2598 but not adopted by the working group in December 2000. The original definition of EF was based on comparison of forwarding on an unloaded network. This experimental Delay Bound (DB) PHB requires a bound on the delay of packets due to other traffic in the network. At the Pittsburgh IETF meeting in August 2000, the Differentiated Services working group faced serious questions regarding RFC 2598 - the group's standards track definition of the Expedited Forwarding (EF) Per Hop Behavior (PHB). An 'EF Design Team' volunteered to develop a re-expression of RFC 2598, bearing in mind the issues raised in the DiffServ group. At the San Diego IETF meeting in December 2000 the DiffServ working group decided to pursue an alternative re-expression of the EF PHB. This memo provides information for the Internet community.

This document defines a 16 bit encoding mechanism for the identification of differentiated services Per Hop Behaviors in protocol messages. It replaces RFC 2836. [STANDARDS-TRACK]

This document defines and discusses Per-Domain Behaviors in detail and lays out the format and required content for contributions to the Diffserv WG on PDBs and the procedure that will be applied for individual PDB specifications to advance as WG products. This format is specified to expedite working group review of PDB submissions. This memo provides information for the Internet community.

This document describes a framework by which Integrated Services may be supported over Diffserv networks. This memo provides information for the Internet community.

This memo describes several Rate Adaptive Shapers (RAS) that can be used in combination with the single rate Three Color Markers (srTCM) and the two rate Three Color Marker (trTCM) described in RFC2697 and RFC2698, respectively. This memo provides information for the Internet community.

This document considers the interaction of Differentiated Services (diffserv) with IP tunnels of various forms. This memo provides information for the Internet community.

This memo defines a Time Sliding Window Three Colour Marker (TSWTCM), which can be used as a component in a Diff-Serv traffic conditioner. This memo defines an Experimental Protocol for the Internet community.

This document defines a Single Rate Three Color Marker (srTCM), which can be used as component in a Diffserv traffic conditioner. This memo provides information for the Internet community.

This document defines a Two Rate Three Color Marker (trTCM), which can be used as a component in a Diffserv traffic conditioner. This memo provides information for the Internet community.

This document presents a differentiated services architecture for the internet. This memo provides information for the Internet community.

This document defines a general use Differentiated Services (DS) Per-Hop-Behavior (PHB) Group called Assured Forwarding (AF). [STANDARDS-TRACK]

This document defines the IP header field, called the DS (for differentiated services) field. [STANDARDS-TRACK]

This document defines an architecture for implementing scalable service differentiation in the Internet. This memo provides information for the Internet community.

This document describes the Provider Architecture for Differentiated Services and Traffic Engineering (PASTE) for Internet Service Providers (ISPs). This memo provides information for the Internet community.