1、 International Telecommunication Union ITU-T Y.1562TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2007) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects Quality of service and network performance Framework for higher-l
2、ayer protocol performance parameters and their measurementITU-T Recommendation Y.1562 ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, applications and middleware Y.
3、200Y.299 Network aspects Y.300Y.399 Interfaces and protocols Y.400Y.499 Numbering, addressing and naming Y.500Y.599 Operation, administration and maintenance Y.600Y.699 Security Y.700Y.799 Performances Y.800Y.899 INTERNET PROTOCOL ASPECTS General Y.1000Y.1099 Services and applications Y.1100Y.1199 A
4、rchitecture, access, network capabilities and resource management Y.1200Y.1299 Transport Y.1300Y.1399 Interworking Y.1400Y.1499 Quality of service and network performance Y.1500Y.1599 Signalling Y.1600Y.1699 Operation, administration and maintenance Y.1700Y.1799 Charging Y.1800Y.1899 NEXT GENERATION
5、 NETWORKS Frameworks and functional architecture models Y.2000Y.2099 Quality of Service and performance Y.2100Y.2199 Service aspects: Service capabilities and service architecture Y.2200Y.2249 Service aspects: Interoperability of services and networks in NGN Y.2250Y.2299 Numbering, naming and addres
6、sing Y.2300Y.2399 Network management Y.2400Y.2499 Network control architectures and protocols Y.2500Y.2599 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. Y.1562 (03/2007) i ITU-T Recommendation Y.1562 Framewo
7、rk for higher-layer protocol performance parameters and their measurement Summary ITU-T Recommendation Y.1562 defines the parameters and methodology used to assess the service provided by higher-layer protocols. Parameters include performance parameters and availability parameters, such as high-laye
8、r packet transfer throughput, service delay, availability and so on. The methodology and parameters described in this Recommendation are applicable to networks supporting both IPv4 and IPv6. Source ITU-T Recommendation Y.1562 was approved on 1 March 2007 by ITU-T Study Group 12 (2005-2008) under the
9、 ITU-T Recommendation A.8 procedure. Keywords Availability, DHCP, FTP, higher-layer protocol, HTTP, performance, QoS. ii ITU-T Rec. Y.1562 (03/2007) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommu
10、nication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assem
11、bly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology whic
12、h fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with th
13、is Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory langua
14、ge such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Re
15、commendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of
16、approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the
17、TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2007 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. Y.1562 (03/2007) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 2 4 Abbreviati
18、ons 2 5 Conventions 2 6 Reference model for higher-layer protocols. 2 6.1 Layered model of higher-layer protocols . 2 6.2 General NGN performance model 3 6.3 Reference model. 4 7 Higher-layer protocol performance parameters 7 7.1 Higher-layer service response delay (HLSRD) 7 7.2 Higher-layer authent
19、ication delay (HLAD) 8 7.3 Higher-layer data transfer delay (HLDTD) 8 7.4 Higher-layer service delay (HLSD) 8 8 Higher-layer protocol availability parameters 9 8.1 Connection establishment success ratio (CESR) 9 8.2 Service success ratio (SSR) 9 8.3 Service availability (SA) 9 Appendix I Embodiment
20、example for higher-layer services 10 Bibliography. 15 ITU-T Rec. Y.1562 (03/2007) 1 ITU-T Recommendation Y.1562 Framework for higher-layer protocol performance parameters and their measurement 1 Scope This Recommendation defines the end-to-end higher-layer performance parameters such as throughput,
21、service availability and so on, and an associated evaluation methodology. The methodology described in this Recommendation relates to end-to-end higher-layer protocols based on IPv4 and IPv6, and the performance parameters described in this Recommendation are used to assess the service status of hig
22、her-layer protocols. The methodology and parameters described in this Recommendation are applicable to networks supporting both IPv4 and IPv6. The node in the end-to-end model described in this Recommendation may be a host, router, switch or network device. The only requirement is that it should sup
23、port a higher-layer protocol and test function. The methodology described in this Recommendation can be used to examine the status of higher-layer protocols which provide service to the customer, and provide performance parameters to assess the service quality. The performance parameters are intende
24、d to be used in planning and offering international higher-layer protocol service. The intended users of this Recommendation include carrier service providers, equipment manufacturers and end users. This Recommendation may be used by service providers in the planning, development, and assessment of
25、IP service that meets user performance needs; by equipment manufacturers as performance information that will affect equipment design; and by end users in evaluating higher-layer protocol service performance. 2 References The following ITU-T Recommendations and other references contain provisions wh
26、ich, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of
27、applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. I
28、TU-T G.1000 ITU-T Recommendation G.1000 (2001), Communications Quality of Service: A framework and definitions. ITU-T G.1010 ITU-T Recommendation G.1010 (2001), End-user multimedia QoS categories. ITU-T I.350 ITU-T Recommendation I.350 (1993), General aspects of quality of service and network perfor
29、mance in digital networks, including ISDNs. ITU-T Y.1540 ITU-T Recommendation Y.1540 (2002), Internet protocol data communication service IP packet transfer and availability performance parameters. ITU-T Y.1541 ITU-T Recommendation Y.1541 (2006), Network performance objectives for IP-based services.
30、 ITU-T Y.1560 ITU-T Recommendation Y.1560 (2003), Parameters for TCP connection performance in the presence of middleboxes. 2 ITU-T Rec. Y.1562 (03/2007) 3 Definitions This Recommendation defines the following term: 3.1 measurement point (MP): A MP is located at the interface between the transmissio
31、n layer and a higher layer on a host that separates the customer network from an attached transmission system, and at which a reference event can be observed and measured. 4 Abbreviations This Recommendation uses the following abbreviations: CESR Connection Establishment Success Ratio DHCP Dynamic H
32、ost Configuration Protocol FTP File Transfer Protocol HLAD Higher-Layer Authentication Delay HLDTD Higher-Layer Data Transfer Delay HLPT Higher-Layer Packet Throughput HLSD Higher-Layer Service Delay HLSRD Higher-Layer Service Response Delay HTTP HyperText Transfer Protocol IP Internet Protocol IPv4
33、 Internet Protocol version 4 IPv6 Internet Protocol version 6 MN Measurement Node MP Measurement Point NMS Network Management System SA Service Availability SSR Service Success Ratio TCP Transmission Control Protocol UDP User Datagram Protocol 5 Conventions None. 6 Reference model for higher-layer p
34、rotocols 6.1 Layered model of higher-layer protocols Figure 6-1 illustrates the layered nature of high-layer protocols. The performance provided to higher-layer service users depends on the performance of the transmission layer, IP layer and other layers. Lower layers include the physical layer and
35、link layer supporting the IP layer. ITU-T Rec. Y.1562 (03/2007) 3 The IP layer provides connectionless, best-effort forwarding service for the transmission layer. There are two versions of the IP protocol: version 4 and version 6. The performance of IPv4 is discussed in ITU-T Y.1541. The performance
36、 of IP layer for IPv6 is for further study. The transmission layer supported by the IP layer provides services for higher protocol layer. There are two kinds of transmission layer protocols: transmission control protocol (TCP) and user datagram protocol (UDP). The performance of TCP is discussed in
37、ITU-T Y.1560; the performance of UDP is for further study. The higher layer provides reliable, end-to-end services for customers, for example, FTP, HTTP, DHCP, and so on. NOTE 1 The performance of higher protocol layers discussed in this Recommendation is applicable to both IPv4 and IPv6. NOTE 2 Per
38、formance interactions among these layers are for further study. Figure 6-1 Layered model for higher layer Example 6.2 General NGN performance model Some NGN applications will involve two or more clients. Familiar examples of application services involving two (or more) clients are instant messaging,
39、 remote control and monitoring, and real-time multi-party gaming. There will also be situations where the server/network interfaces must be considered in assessing application performance. This will be true in any situation where it is important to distinguish application server performance from net
40、work performance, e.g., when the application service provider and the network operator are in different organizations. In such situations, the performance models will involve four types of entities: the communication network, the application server, and two clients, distinguished by the roles they p
41、lay in particular application service instances. The application server may sometimes be viewed as a user of the network service. It may also be important, in some situations, to specify and measure the contributions of individual network portions to the overall end-to-end performance of IP applicat
42、ions, or even to similarly partition an application server. 4 ITU-T Rec. Y.1562 (03/2007) A very general NGN performance model that may reflect these considerations is illustrated in Figure 6-2. This model is consistent, at a very high level, with the NGN functional architecture model defined in ITU
43、-T Rec. Y.2012. It will provide the flexibility to address many, but not all, IP application performance assessment situations. Since adding model interfaces complicates performance assessment, it will be important to use the simplest possible model in any particular application performance study. I
44、n all applications of the NGN performance model, the reference events will be transfers of requests and responses across the depicted interfaces in accordance with standardized client/server protocols. As in the communication case, specific events will be defined in terms of interface protocol state
45、 transitions. A conceptual difference is that in the assessment of application performance, the relevant protocols will be higher “up the stack“ (or stated differently, the performance-significant protocol information will be more deeply embedded in the packets observed at the physical interfaces).
46、It will nevertheless be possible to extract the relevant information at such interfaces. ANI Application Application PKT PKT NGN PKT PKTPKT PKT User NGN UNI UNI NNINNI ANI UserFigure 6-2 General NGN performance model As noted earlier, the functions performed by NGN IP applications will be more diver
47、se, and typically much more complex, than those performed in traditional communication sessions. Application servers are typically designed to process input information in some defined way, to relate it to other input or stored information, or to provide additional, different, or restructured inform
48、ation in response to user requests. Servers frequently also store input information for later retrieval and use by the inputting client or another user. The set of higher-layer applications likely to be provided by NGNs is not bounded, and is therefore not subject to stable classification. 6.3 Refer
49、ence model Figure 6-3 illustrates the reference model for higher-layer protocols and the relationship between reference events and measurement points for a higher-layer protocol session. ITU-T Rec. Y.1562 (03/2007) 5 Figure 6-3 Reference model 6.3.1 Network components 6.3.1.1 router: A device that can forward IP packets based on the content of their IP destination address field and routing information. 6.3.1.2 measurement node: The MN may be a computer, router, L3 switch or tester, which can initiate higher-layer pr
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