1、 ATIS-1000076 ATIS Standard on Reliability and Quality of Service Enablers PSTN Transition to IP Packet Networks Alliance for Telecommunications Industry Solutions Approved February 13, 2017 Abstract This ATIS Standard provides a comprehensive list of standards, technical requirements, and technical
2、 reports that have already been developed in areas of IP packet reliability, priority, and Quality of Service (QoS). The goal is to demonstrate that IP packet networks and services are subjected to a similar level of depth and rigor as the PSTN on issues related to reliability, priority, and QoS. AT
3、IS-1000076 ii Foreword The Alliance for Telecommunication Industry Solutions (ATIS) serves the public through improved understanding between providers, customers, and manufacturers. The Packet Technologies and Systems Committee (PTSC) develops and recommends standards and technical reports related t
4、o services, architectures, and signaling, in addition to related subjects under consideration in other North American and international standards bodies. PTSC coordinates and develops standards and technical reports relevant to telecommunications networks in the U.S., reviews and prepares contributi
5、ons on such matters for submission to U.S. ITU-T and U.S. ITU-R Study Groups or other standards organizations, and reviews for acceptability or per contra the positions of other countries in related standards development and takes or recommends appropriate actions. The mandatory requirements are des
6、ignated by the word shall and recommendations by the word should. Where both a mandatory requirement and a recommendation are specified for the same criterion, the recommendation represents a goal currently identifiable as having distinct compatibility or performance advantages. The word may denotes
7、 an optional capability that could augment the standard. The standard is fully functional without the incorporation of this optional capability. Suggestions for improvement of this document are welcome. They should be sent to the Alliance for Telecommunications Industry Solutions, PTSC, 1200 G Stree
8、t NW, Suite 500, Washington, DC 20005. At the time of consensus on this document, PTSC, which was responsible for its development, had the following leadership: M. Dolly, PTSC Chair (AT new documents continue to be developed. The goal of this document is to demonstrate significant efforts undertaken
9、 by the telecommunications industry to deliver reliable services with desired levels of priority and QoS over packet networks. The standards and documents listed here include work from several ATIS Committees, International Telecommunications Union Telecommunication Sector (ITU-T) Study Groups, and
10、the Internet Engineering Task Force (IETF) and the 3rd Generation Partnership Project (3GPP). 2 References The following standards contain provisions which, through reference in this text, constitute provisions of this ATIS Standard. At the time of publication, the editions indicated were valid. All
11、 standards are subject to revision, and parties to agreements based on this ATIS Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. 2.1 Normative References ATIS-0100003, User Plane Priority Levels for IP Networks and Service
12、s.1ATIS-0100006, Service Restoration Priority Levels for IP Networks.11This document is available from the Alliance for Telecommunications Industry Solutions (ATIS) at: . ATIS-1000076 2 ATIS-0100008, Defects per Million (DPM) Metric for Transaction Services such as VoIP.1ATIS-0100009, Overview of St
13、andards in Support of Emergency Telecommunications Service (ETS).1ATIS-0100011, Priority for NS/EP Services in NGN/IP Environment Role of TSP.1ATIS-0100012, Standard Outage Classification.1ATIS-0100020, Availability Metric for IP-Based Networks and Services.1ATIS-0100021, Analysis of FCC-Reportable
14、Service Outage Data Version 2.1ATIS-0100022, Priority Classification Levels for Next Generation Networks.1ATIS-0100025, A Methodology for Estimating the Availability of Access IP Routers in Terms of Customer Facing Line Card Availability.1ATIS-0100028, Network Resiliency Planning for Enterprise Cust
15、omers.1ATIS-0100030, Mean Time Between Outages A Generalized Metric for Assessing Production Failure Rates in Telecommunications Network Elements.1ATIS-0100032, Relation Between ITU-T (Y.1541/Y.1221) and 3GPP UMTS/LTE QoS Classes.1ATIS-0100035, Telepresence Quality of Experience and Quality of Servi
16、ce.1ATIS-0100037, Impact Weighted MTBF A Metric for Assessing Reliability of Hierarchical Systems.1ATIS-0100038, Analysis of Large DS3 FCC Reportable Outages.1ATIS-1000011, ETS Packet Priority for IP NNI Interfaces Use of Existing Diffserv per Hop Behaviors.1ATIS-1000020, ETS Packet Priority for IP
17、NNI Interfaces Requirements for a Separate Expedited Forwarding Mechanism.1ATIS-1000070, Emergency Telecommunications Service (ETS) Roadmap ITU-T Recommendation G.1091, QoE Requirements for Telepresence Services.2ITU-T Recommendation J.147, Objective picture quality measurement method by use of in-s
18、ervice test signals.2ITU-T Recommendation J.148, Requirements for an objective perceptual multimedia quality model.2ITU-T Recommendation J.241, Quality of service ranking and measurement methods for digital video services delivered over broadband IP networks.2ITU-T Recommendation J.244, Full referen
19、ce and reduced reference calibration methods for video transmission systems with constant misalignment of spatial and temporal domains with constant gain and offset.2ITU-T Recommendation J.246, Perceptual visual quality measurement techniques for multimedia services over digital cable television net
20、works in the presence of a reduced bandwidth reference.2ITU-T Recommendation J.247, Objective perceptual multimedia video quality measurement in the presence of a full reference.2ITU-T Recommendation J.248, Requirements for operational monitoring of video-to-audio delay in the distribution of televi
21、sion programs.2ITU-T Recommendation J.249, Perceptual video quality measurement techniques for digital cable television in the presence of a reduced reference.2ITU-T Recommendation J.260, Requirements for preferential telecommunications over IPCablecom networks.2ITU-T Recommendation J.261, Framework
22、 for implementing preferential telecommunications in IPCablecom and IPCablecom2 networks.2ITU-T Recommendation J.262, Specifications for authentication in preferential telecommunications over IPCablecom2 networks.2ITU-T Recommendation J.263, Specification for priority in preferential telecommunicati
23、ons over IPCablecom2 networks.2ITU-T Recommendation J.340, Reference algorithm for computing peak signal to noise ratio of a processed video sequence with compensation for constant spatial shifts, constant temporal shift, and constant luminance gain and offset.2ITU-T Recommendation J.341 (2011), Obj
24、ective perceptual multimedia video quality measurement of HDTV for digital cable television in the presence of a full reference.2ITU-T Recommendation J.342 (2011), Objective multimedia video quality measurement of HDTV for digital cable television in the presence of a reduced reference signal22Avail
25、able from the ITU-T at: . ATIS-1000076 3 ITU-T Recommendations J.343.1-6, Hybrid perceptual bitstream video quality assessment family of Recommendations.2ITU-T Recommendation P.913, Methods for the subjective assessment of video quality, audio quality and audiovisual quality of Internet video and di
26、stribution quality television in any environment.2ITU-T Recommendation P.1201, Parametric non-intrusive assessment of audiovisual media streaming quality - Higher resolution application area.2ITU-T Recommendation P.1202, Parametric non-intrusive bitstream assessment of video media streaming quality.
27、2ITU-T Recommendation Y.1540, Internet protocol data communication service IP packet transfer and availability performance parameters.2ITU-T Recommendation Y.1561, Performance and availability parameters for MPLS networks.2ITU-T Recommendation Y.1541, Network performance objectives for IP-based serv
28、ices.2ITU-T Recommendation Y.1542, Framework for achieving end-to-end IP performance objectives.2ITU-T Recommendation Y.1561, Performance and availability parameters for MPLS networks.2ITU-T Recommendation Y.1566, Quality of service mapping and interconnection between Ethernet, Internet protocol and
29、 multiprotocol label switching networks.2ITU-T Recommendation Y.2171, Admission control priority levels in Next Generation Networks.2ITU-T Recommendation Y.2172, Service restoration priority levels in Next Generation Networks.2ITU-T Recommendation Y.2174, Distributed RACF architecture for MPLS netwo
30、rks.2IETF RFC 2597, Assured Forwarding PHB Group.3IETF RFC 3246, An Expedited Forwarding Per Hop Behavior (PHB).3IETF RFC 3260, New Terminology and Clarifications for DiffServe.3IETF RFC 3564, Requirements for Support of Differentiated Services-aware MPLS Traffic Engineering.3IETF RFC 5865, A Differ
31、entiated Services Code Point (DSCP) for Capacity-Admitted Traffic.33GPP TS 23-203, Policy and Charging Control Architecture.43GPP TS 22-153, Multimedia Priority Service.42.2 Informative References ATIS-I-0000034, PSTN Transition Focus Group Assessment and Recommendations.13 Acronyms they allow signi
32、ficantly more flexibility for network operators to provide innovative services over wired and wireless technologies. Thus IP networks convey all types of communications applications in the form of packets that are transported (routed) to their destinations by IP routers. The point to note is that al
33、l application types are transported as IP packets; in the early days of the Internet, all packets were “equal” in terms of criticality and importance. That thinking has evolved as there is growing awareness that certain types of communications are deemed to be more important than others. For that re
34、ason, the telecommunications industry has started to adopt technologies based on industry standards that ATIS-1000076 6 provide a higher degree of priority, reliability, and QoS to specific classes of telecommunications traffic over others. Examples of traffic classes include the following: Emergenc
35、y Telecommunications Service (ETS) Government Emergency Telecommunications Service (GETS), Wireless Priority Services (WPS), and National Security/Emergency Preparedness Next Generation GETS (NS/EP NGN-GETS) are all facets of the USA instantiation of the international standard for ETS E.107. In addi
36、tion to high degrees of reliability and QoS, this class of service is also given the highest priority for admission control, priority when admitted, and restoration. Several industry standards have been developed for this purpose. Voice over IP (VoIP) The entire set of PSTN Voice calls are slated to
37、 be completely transported over IP networks. The telecommunications industry has adopted many capabilities and standards to ensure that reliability and QoS for VoIP services is similar to those experienced over the PSTN. “Private Network Services” Typically, network operators provide a suite of serv
38、ices to specific entities such as large corporations and Federal, State, and Local Governments. The range of services include VoIP, Data, and Video communications. Depending on the required contracts between the operator and the entity, these services often are segregated from the rest of the operat
39、ors traffic in the form of Virtual Private Networks (VPN). The agreed upon assurances include requirements for reliability and QoS. Special Services Specific service offerings to the general population and business/government communities include Internet Protocol Television (IPTV), Mobility services
40、, Telepresence, etc. IP networks allow the creation and distribution of such services over a single network; often with specified degrees/assurances of reliability and QoS. Internet Traffic General “Best Effort” traffic that does not require any assurance of reliability and QoS fits into this class.
41、 Any type of traffic that does not require specific assurances from the network operator fits into this class. Examples include Web surfing, email, Over-the-Top (OTT) video5requests (e.g., YouTube), etc. The above set of traffic classes are representative of the types of traffic delivered by network
42、 operators. Each class has certain requirements for reliability and QoS; in addition, priority assurances are also specified for critical traffic classes for certain types of network functions such as admission control and restoration. At the same time, network operators need to ensure that network
43、and network element reliability and QoS also conform to certain requirements. Standards specifications have been developed to assist network operators and equipment suppliers to ensure minimum acceptable levels of equipment reliability such that element and network-wide availability and QoS can be a
44、chieved. The objective of this document is to provide an in-depth and comprehensive overview of reliability, QoS, and priority standards that have been developed for the purpose of supporting IP network operators to achieve desired goals and Service Level Agreements at service, equipment, and networ
45、k levels. These standards demonstrate that the resulting expectations for IP network/service reliability/availability and QoS are comparable to those achieved by the PSTN. QoS standards are described in clause 6. Reliability standards are described in clause 7. Priority standards are described in cl
46、ause 8. 5 Quality of Service Standards Overview for IP Packet Networks IP-based Quality of Service standardization was initially proposed in ATIS Committee T1A1. The focus was on determining a set of performance ranges for services offered over IP-based packet networks. Some development work was ini
47、tiated in T1A1; however the bulk of the standards effort was eventually completed in the ITU-T under Study Groups 13 and 12. Follow up performance measurement work is undergoing in the ITU-T Study Group 12 as well as in the IETF under the IP Performance Metrics (ippm) Working Group. Under the ATIS N
48、etwork Performance, Reliability and Quality of Service Committee (PRQC), Quality of Service work focused on potential alignment between wireline and wireless service performance classes and an initial development of telepresence QoS requirements. 5Note that OTT video accounts for the majority of “Be
49、st Effort” ISP traffic requests. ATIS-1000076 7 A representative set of standards and recommendations from these three Standards bodies are presented below. 5.1 ITU-T Standards ITU-T standards are summarized as follows. 1. ITU-T Recommendation Y.1541, Network performance objectives for IP-based services: a. Summary: This Recommendation defines classes of network quality of service (QoS) with objectives for Internet Protocol network performance parameters. Two of the classes contain provisional performance objectives. These classes are intended to be the bas
