The following technical terms are taken from[RFC 2474] [RFC 2475]. The tabulated form gives the reader a comprehensive information of the related terms used here.

 

Behaviour Aggregate	a collection of packets with the same code point crossing a link in a particular direction.
Boundary link	a link connecting the edge nodes of two domains.
Classifier	an entity which selects packets based on the content of packet headers according to defined rules.
Class Selector Codepoint	any of the eight code points in the range 'xxx000' (where 'x' may equal '0' or '1').
Class Selector Compliant PHB	a per-hop behavior satisfying the Class Selector PHB Requirements.
Code point	a specific value of the DSCP portion of the DS field. Recommended code points should map to specific standardized PHBs.  Multiple code points may map to the same PHB.
Differentiated Services Boundary	the edge of a DS domain, where classifiers and traffic conditioners are likely to be deployed.  A differentiated services boundary can be further sub-divided into ingress and egress nodes, where the ingress/egress nodes are the downstream/upstream nodes of a boundary link in a given traffic direction.  A differentiated services boundary typically is found at the ingress to the first-hop differentiated services-compliant router  (or network node) that a host's packets traverse, or at the egress of the last-hop differentiated services-compliant router or network node that packets traverse before arriving at a host.
Differentiated Services-Compliant	in compliance with the requirements specified in this document.
Differentiated Services Domain	a contiguous portion of the Internet over which a consistent set of differentiated services policies are administered in a coordinated fashion.
Differentiated Services Field	the IPv4 header TOS octet or the IPv6 Traffic Class octet when interpreted in conformance with the definition given in this document.
DS behavior aggregate	a collection of packets with the same DS code point crossing a link in a particular direction.
DS boundary node	a DS node that connects one DS domain to a node either in another DS domain or in a domain that is not DS-capable.
DS-capable	capable of implementing differentiated services as described in this architecture; usually used in reference to a domain consisting of DS-compliant nodes.
DS egress node	a DS boundary node in its role in handling traffic as it leaves a DS domain
DS ingress node	a DS boundary node in its role in handling traffic as it enters a DS domain.
DS interior node	a DS node that is not a DS boundary node.
DS field	the IPv4 header TOS octet or the IPv6 Traffic Class octet when interpreted in conformance with the definition given in [DSFIELD].  The bits of the DSCP field  encode the DS code point, while the remaining bits are currently unused.
DS node	a DS-compliant node.
DS region
Downstream DS domain	the DS domain downstream of traffic flow on a boundary link.
Dropper	a device that performs dropping.
Dropping	the process of discarding packets based on specified rules.
Legacy node	a node which implements IPv4 Precedence as defined in [RFC791,RFC1812] but which is otherwise not DS-compliant.
Mechanism	The implementation of one or more per-hop behaviors according to a particular algorithm.
Microflow	a single instance of an application-to-application flow of packets which is identified by source address, destination address, protocol id, and source port, destination port (where applicable).
Marker	a device that performs marking.
Marking	the process of setting the DS code point in a packet based on defined rules; pre-marking, re-marking.
Meter	a device that performs metering.
Metering	the process of measuring the temporal properties (e.g., rate) of a traffic stream selected by a classifier. The instantaneous state of this process may be used to affect the operation of shaper, or dropper, and/or may be used.
Per-hop Behavior (PHB)	a description of the externally observable forwarding treatment applied at a differentiated services-compliant  node to a behavior aggregate.  The description of a PHB SHOULD be  sufficiently detailed to allow the construction of predictable services, as documented in.
Per-hop Behavior Group	a set of one or more PHBs that can only be meaningfully specified and implemented simultaneously, due to a common constraint applying to all PHBs in the set such as a queue servicing or queue management policy.  Also PHB Group.
Policing	the process of discarding packets (by a dropper) within a traffic stream in accordance with the state of a corresponding meter enforcing a traffic profile.
Pre-mark	to set the DS code point of a packet prior to entry into a downstream DS domain.
Provider DS domain	the DS-capable provider of services to a source domain.
Re-mark	to change the DS code point of a packet, usually performed by a marker in accordance with a TCA.
Service	the overall treatment of a defined subset of a customer's traffic within a DS domain or end-to-end.
Service Level Agreement (SLA)	a service contract between a customer and a service provider that specifies the forwarding service a customer should receive.  A customer may be a user organization (source domain) or another DS domain (upstream domain).  A SLA may include traffic conditioning rules which constitute a TCA in whole or in part.
Service Provisioning Policy	a policy which defines how traffic conditioners are configured on DS boundary nodes and how traffic streams are mapped to DS behavior aggregates to achieve a range of services.
Shaper	a device that performs shaping.
Shaping	the process of delaying packets within a traffic stream to cause it to conform to some defined traffic profile.
Source domain	a domain which contains the node(s) originating the traffic receiving a particular service.
Traffic Conditioning	control functions that can be applied to a behavior aggregate, application flow, or other operationally useful subset of traffic, e.g., routing updates.  These MAY include metering, policing, shaping, and packet marking.  Traffic conditioning is used to enforce agreements between domains and to condition traffic to receive a differentiated service within a domain by marking packets with the appropriate code point in the DS field and by monitoring and altering the temporal characteristics of the aggregate where necessary.
Traffic Conditioner	an entity that performs traffic conditioning functions and which MAY contain meters, policers, shapers, and markers.  Traffic conditioners are typically deployed in DS boundary nodes.
Traffic Conditioning Agreement (TCA)	an agreement specifying classifier rules  and any corresponding traffic profiles and metering, marking, discarding and/or shaping rules which are to apply to the traffic streams selected by the classifier. A TCA encompasses all of the traffic conditioning rules explicitly specified within a SLA along with all of the rules implicit from the relevant service requirements and/or from a DS domain's service provisioning policy.
Traffic Profile	description of the temporal properties of a traffic stream such as rate and burst size.
Traffic stream	an administratively significant set of one or more microflows which traverse a path segment. A traffic stream may consist of the set of active microflows which are selected by a particular classifier.
Upstream DS domain	the DS domain upstream of traffic flow on a boundary link.