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Overview of Quality of Service (QoS)

This overview covers the concept of Quality of Service (QoS) and its importance in meeting user needs. It also discusses the challenges faced by network equipment manufacturers, terminal device manufacturers, network operators, service providers, and regulators in ensuring QoS.

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Overview of Quality of Service (QoS)

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  1. Overview of Quality of Service (QoS) APT-ITU workshop on the International Telecommunications Regulations Bangkok, 6-8 February 2012 Richard Hill, ITU

  2. Content Introduction Global Challenges The ITU’s past and current Work on QoS Other International Agreements Proposals made on this topic

  3. Introduction • Quality of Service (QoS) • The totality of characteristics of a telecommunications service that bear on its ability to satisfy stated and implied needs of the user of the service • Characteristics can be measured by objective means • level meter • delay counter • etc. • Often confused with Network Performance (NP) • IETF uses QoS to describe the performance of functional services in network layer models • QoS often more precisely named as "end-to-end QoS"

  4. Introduction User Perception influenced by much more: 4

  5. Introduction User Perception of quality not limited to the objective characteristics at the man-machine interface For end users counts the quality that they personally experience during their use of a telecommunication service Quality of Experience (QoE) takes into account additional subjective parameters stemming from user expectations from the context, in which the user is embedded during the use of the service, such as personal mood environment potential discrepancy between the service offered and individual users reading additional features into the service 5

  6. Content Introduction Global Challenges The ITU’s past and current Work on QoS Other International Agreements Proposals made on this topic

  7. Global Challenges Move from traditional networks based on dedicated service-channels Towards on a single packet based transport infrastructure With integrated (transport) services Pre-defined transmission planning of QoS has become a major challenge: Fixed allocation of resources is no longer possible Packet-based network quality parameter requirements are pretty undefined Responsibility for end-to-end QoS has been lost Services must be considered as applications executed in the terminal devices IP networks cannot provide for self standing end-to-end QoS Only transport classes, which enable QoS differentiation QoS Challenges depend strongly on role of stakeholders 7

  8. 1) Challenges for Network Equipment Manufacturers Rely on the QoS related performance requests (of network and system functions) from network operators and service providers Ideally, network equipment manufacturers would participate in the QoS work of SDOs To standardize the QoS and performance requirements between several parties involved in the network business Often no visible incentive on the short term Return of investment cannot easily be seen 8

  9. 2) Challenges for Terminal Device Manufacturers • Confronted with a mass market • Move away from minimum attachment requirements • No harm to the network, not necessarily high QoS • Towards terminal standards which target the possibility of provision of high-level end-to-end QoS to the customer • Acceptance in the market based on other factors • Price • Other functions of terminals • Applications available for that terminal • Brand • End-to-end QoS - not in the first place • "kids prefer the pink phone!" 9

  10. 3) Challenges for Network Operators and Service Providers • Huge investments in both infrastructure and access technology, likely to partially • Investing in new capacity, and • Rationing existing capacity • Traffic management tools • Increase efficiency of managing existing network capacity • Appropriateness of different approaches to traffic management is at the heart of the Net Neutrality debate • Important to bear in mind that traffic management has always beneficial aspects • Commonly used to protect safety-critical traffic • Question is not whether traffic management is acceptable in principle, but whether particular approaches to traffic management cause concern • Network operators and service providers may or may not use traffic management as a welcome method towards suppressing competition • Opening access and core packet networks as pure bit pipes will probably not provide the envisaged revenues • Therefore network operators and service providers are aiming at providing services on top of the bit stream itself 10

  11. 4) Challenges for Regulators and Administrations • Responsibility to consumer protection affected by rapid introduction of vendor-specific new services • Also required to set a right balance between service competition and infrastructure competition • In the early days of the move towards end-to-end services being no longer provided on a fixed, well-known platform, it still seemed to be fairly easy to require that the new technology provide QoS "not less than in the ISDN era" • Today it is easy to lose the overview of proprietary services "on-net" and the respectively offered QoS • Services are not standardized • For interconnection scenarios (one of the major responsibilities of the ITU, and one of the main purposes of the ITRs) one would need specific service agreements for each network-to-network-interface (NNI). 11

  12. In contrast, Regulators and Administrations have seen in the recent past that the un-managed Internet has led to the creation of new services offered "over the top" • Important factor contributing to the economical benefits • Regulators and Administrations to have a close look • Conditions under which access to services in comparison to the access to the Internet is being provided • There may be a certain percentage of the bandwidth or of the capacity reserved for the on-net services which then are not available for the access to the Internet

  13. 5) Challenges for Customers • Personal affairs of using telecommunication services • Discrepancy between advertised and actual delivery speeds of the network • Consumers may not be able to detect the actual applications of discriminating traffic management techniques and find it difficult to distinguish between the effects of traffic management techniques on QoS from the effects of other quality degrading factors • A consumer observing that traffic is routinely throttled may not know whether this is done by intention, or is caused by other factors • Traffic management techniques and policies are difficult to understand for consumers • Consumers may find it difficult to act upon such information 13

  14. ... in Technical Terms • Dramatic increase in mobile communication, both in terms of the number of registered devices and of the volume of requested resources makes it is quite likely that migration scenarios and hybrid connections with existing wire-bound and traditional networks and terminals will be neglected and appropriate QoS standards will not be established or enforced • Main technical parameters to consider will be: • speed (data throughput) of the access network • congestion in the backbone • end-to-end delay (latency) • delay-variation (jitter) • packet loss (loss of information) -to-end QoS

  15. Jitter is the variation in delay between different packets • Compensation (by de-jitter buffers) converts jitter into additional delay • Packet loss may be concealed • Essential information may be lost • Bad terminal implementations may destroy reasonable performance delivered from the network(s) • Users will not be able to judge the difference in end-to-end QoS

  16. Current Policy Challenges • Need to consider new approaches to anchor national strategies or regulatory frameworks around the multi-facetted concept of QoS required • To set and keep the right balance between service and infrastructure competitions • To address the challenges associated with QoS on the telecommunication network • To continue providing adequate QoS, network operators and service providers claim to need a certain traffic management over increasingly congested networks • This might include data restrictions, traffic throttling, filtering and/or the use of data caps of thresholds • Once the cap is exceeded, customers or end-users may be, knowingly or not, confronted with the fact that, "Internet access" provided to them is no longer Internet access, but a service provided by their ISP; • Such possible circumstances have influenced debates over ‘net neutrality’ and ‘differentiated traffic management’ • These issues are increasingly likely to come to the fore, if data traffic continues to grow at its current projected rate • Currently, many regulators are launching public consultations and investigations into traffic throttling practices

  17. To continue providing adequate QoS, network operators and service providers claim to need a certain traffic management over increasingly congested networks • This might include data restrictions, traffic throttling, filtering and/or the use of data caps of thresholds • Once the cap is exceeded, customers or end-users may be, knowingly or not, confronted with the fact that, "Internet access" provided to them is no longer Internet access, but a service provided by their ISP; • Such possible circumstances have influenced debates over ‘net neutrality’ and ‘differentiated traffic management’ • These issues are increasingly likely to come to the fore, if data traffic continues to grow at its current projected rate • Currently, many regulators are launching public consultations and investigations into traffic throttling practices

  18. Best Practice Guidelines for Enabling Open Access from ITU’s Global Symposium for Regulators (GSR) in 2010 Recommend that only objectively justifiable differentiations be made in the way in which various data streams are treated The Guidelines stress the importance of legislation to set out the general principles of open access: non-discrimination, effectiveness and transparency. The European Commission (EC) policy on net neutrality published in April 2011, The Open Internet and Net Neutrality in Europe calls for greater disclosure of traffic management practices recognizes that traffic management is necessary to ensure the smooth flow of Internet traffic

  19. One of the key policy questions regarding network neutrality regulation is, whether to ban optional business-to-business transactions between broadband ISPs and content providers or application providers for enhanced QoS in the delivery of “their” packets over the network The discussions have significant economic and financial aspects Affect who pays for what with respect to delivery of the network infrastructure and content. This in turn affects how future infrastructure will be financed and rolled out. Much of the traffic growth is coming from video Some fixed-line operators have been seeking for a way to implement differentiated pricing in order to increase their revenues

  20. In the European Union, discussions are taking place to one degree or another regarding the following: The ability of consumers to address all legal content on the Internet. Transparency, in the sense of clear information on services and prices. Non-discrimination, in the sense of not prioritizing certain content or applications in harmful ways. Traffic management, in the sense of intervening in the flow of traffic, for example to optimize bandwidth or to eliminate spam. Differentiation, in the sense of allowing customers to choose service offers that differ with respect to characteristics such as price and speed.

  21. Status of Net Neutrality Initiatives in selected Countries

  22. Content Introduction Global Challenges The ITU’s past and current Work on QoS Other International Agreements Proposals made on this topic

  23. The ITU’s past and current Work on QoS The ITU has a long-standing history of QoS Work Starting as early as 1957 the ITU has been conducting expert work in the fields of transmission planning, subjective testing and standards for telephone sets. Since 1986 the Speech Quality Experts Group (SQEG) provided coordination of the quality requirements and subjective testing methodologies for speech coding algorithms Since 1997 the Video Quality Experts Group (VQEG) provides coordination of the quality requirements and subjective testing methodologies for video coding algorithms Today, in the ITU-T, Study Group 12 is the Lead Study Group on Performance, Quality of Service (QoS) and Quality of Experience (QoE) 23

  24. The ITU’s past and current Work on QoS There are approximately 175 Recommendations, 7 Supplements and 3 Handbooks on QoS published by the ITU and in force. Recently, a free download of ITU-T Test Signals for Telecommunication Systems was provided. POLQA (Perceptual Objective Listening Quality Assessment) as per new Rec. ITU-T P.863 is the most sophisticated tool the ITU ever published for assessment of a QoS parameter "by objective means“. Listening Quality can be "measured" with excellent accuracy, e.g. during mobile network drive-by testing. 24

  25. The ITU’s past and current Work on QoS Rec. ITU-T Y.1541 (Network performance objectives for IP-based services) provides technical parameters for the differentiation of IP network traffic classes, encompassed by a huge number of appendices explaining application scenarios and background. Rec. Y.1542 (Framework for achieving end-to-end IP performance objectives) considers various approaches toward achieving end-to-end (UNI‑UNI) IP network performance objectives. The ITU GSR10 Best Practice Guidelines for Enabling Open Access have been developed (available at www.itu.int/ITU-D/treg/bestpractices.html ). 25

  26. Challenges for Standards Developing Organizations (SDOs) Standards Developing Organizations (SDOs), like ITU-T, The European Telecommunications Standards Institute (ETSI), or The Internet Engineering Task Force (IETF); Have collective knowledge and expertise with respect to QoS related to the change of paradigms in networks and terminals regarding to planning and possible regulation of end-to-end QoS However, SDOs are seeing increasing cases where stakeholders decided to rely on industry standards instead of globally recognized standards 26

  27. Content Introduction Global Challenges The ITU’s past and current Work on QoS Other International Agreements Proposals made on this topic

  28. Other International Agreements • No significant internationally binding agreements on end-to-end QoS outside the ITU • Specification work takes place in some industry fora • ETSI Technical Committee "Speech and multimedia Transmission Quality" (STQ) • Terminals and networks for speech and media quality • End-to-end single multimedia transmission performance • QoS parameters for networks and services • QoE descriptors and methods

  29. Content Introduction Global Challenges The ITU’s past and current Work on QoS Other International Agreements Proposals made on this topic

  30. Proposals made on this topic • Many proposals in recent years • Technical aspects of management of QoE • In various forums, including ETSI • Most of these items have been on the table in ITU-T Study Group 12 • Work is contribution-driven, • Questionable whether new standards will be established • Other kind of approach comes from regulators • Seeking balance between • the protection of the rights of consumers and • excessively rigid regulation • Ofcom in the UK have proposed "easy-to-understand" labelling • as illustrated on the next slides

  31. Elements for "easy-to-understand" labelling

  32. Illustrative QoE Summary for 3 hypothetical ISPs

  33. Illustrative transparent traffic management status representations

  34. Proposals made on this topic • Regarding the so-called “net-neutrality” debate, some proposals presented to CWG-WCIT may touch upon some of these topics. • For example, • Member States shall ensure transparency with respect to retail and wholesale prices, costs, and quality of service. • Member States shall take measures to ensure that an adequate return is provided on investments in network infrastructures. If this cannot be achieved through market mechanisms, then other mechanisms may be used. • Member States shall [take measures to] ensure that fair compensation is received for carried traffic (e.g. interconnection or termination). Regulatory measures may be imposed to the extent that this cannot be achieved through market mechanisms. • However, there is no consensus regarding such proposals

  35. It should be noted that the ITRs contain provisions regarding the right to communicate, a topic which is sometimes discussed in the context of “Net Neutrality”. - Art.3.4 of ITRs states “Subject to national law, any user, by having access to the international network established by an administration (or recognized private operating agency), has the right to send traffic. A satisfactory quality of service should be maintained to the greatest extent practicable, corresponding to relevant CCITT Recommendations”. • Proposals have been made to revise this provision, for example, to state that “Member States recognize the right of the public to correspond by means of the international service of public correspondence.” • It should be noted that Art.34 of ITU Constitution provides that Member States reserve the right to cut off, in accordance with their national law, any private telecommunications which may appear dangerous to the security of the State or contrary to its laws, to public order or to decency.

  36. Thank you

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