RMD-QOSM: The NSIS Quality-of-Service Model for Resource Management in Diffserv

Abstract

This document describes a Next Steps in Signaling (NSIS) Quality-ofService (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.

QSPEC Template for the Quality-of-Service NSIS Signaling Layer Protocol (NSLP)

“…A QOSM is a method to achieve QoS for a traffic flow, e.g., IntServ Controlled Load [CL-QOSM], Resource Management with Diffserv [RFC5977], and QoS signaling for Y.1541 QoS classes [RFC5976]. A QOSM specifies a set of QSPEC parameters that describe the QoS desired and how resources will be managed by the RMF.…”

“…This document defines a number of QSPEC parameters; additional parameters may be defined in separate QOSM specification documents. For example, QSPEC parameters are defined in [RFC5976] and [RFC5977].…”

“…As with constraints parameters and other QSPEC parameters, Traffic Handling Directives parameters may be defined in QOSM specifications in order to provide support for QOSM-specific resource management functions. Such QOSMspecific parameters are already defined, for example, in [RFC5976], [RFC5977], and [CL-QOSM]. Generally, a Traffic Handling Directives parameters is expected to be set by the QNI in <QoS Desired>, and to not be included in <QoS Available>.…”

“…An application MAY like to reserve resources for packets with a particular QoS class, e.g., Y.1541 QoS class [Y.1541] or Diffserv-aware MPLS traffic engineering (DSTE) class type [RFC3564,RFC4124]. These parameters are useful in various QOSMs, e.g., [RFC5976], [RFC5977], and other QOSMs yet to be defined (e.g., DSTE-QOSM). This is intended to provide guidelines to QOSMs on how to encode these parameters; use of the PHB class parameter is illustrated in the example in the following section.…”

“…The QoS NSLP protocol is able to signal QoS reservations for different QOSMs, wherein all information specific to a QOSM is encapsulated in the QSPEC object, and only the RMF specific to a given QOSM will need to interpret the QSPEC. Examples of QOSMs are IntServ, Diffserv admission control, and those specified in [CL-QOSM], [RFC5976], and [RFC5977]. While the base protocol is QOSM-agnostic, the parameters that can be carried in the QSPEC object are possibly closely coupled to specific models.…”