Network Working Group Y. Kikuchi Internet-Draft Kochi University of Technology Intended status: Informational S. Matsushima Expires: January 9, 2009 Softbank Telecom Corp. K. Nagami Intec Netcore Inc. S. Uda Japan Advanced Institute of Science and Technology Jul 08, 2008 Requirements of One-way Passive Measurement for End-to-End Quality draft-kikuchi-passive-measure-reqs-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on January 9, 2009. Kikuchi, et al. Expires January 9, 2009 [Page 1] Internet-Draft draft-kikuchi-passive-measure-reqs-00.txt Jul 2008 Abstract This draft describes the necessary requirements to passively measure end-to-end quality and to monitor them via applicable ways. This feature is crucial for Service Providers (SPs), especially who provide transports with Service Level Agreements (SLAs). Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements notation . . . . . . . . . . . . . . . . . . 3 2. Service Model . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Motivations . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.1. Active vs. Passive . . . . . . . . . . . . . . . . . . . . 6 4.2. Quality Evaluation . . . . . . . . . . . . . . . . . . . . 6 4.3. Getting Quality Information . . . . . . . . . . . . . . . 6 4.4. Overhead Consideration . . . . . . . . . . . . . . . . . . 7 5. Security Considerations . . . . . . . . . . . . . . . . . . . 8 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 9 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 6.1. Normative References . . . . . . . . . . . . . . . . . . . 10 6.2. Informative References . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 Intellectual Property and Copyright Statements . . . . . . . . . . 12 Kikuchi, et al. Expires January 9, 2009 [Page 2] Internet-Draft draft-kikuchi-passive-measure-reqs-00.txt Jul 2008 1. Introduction This draft describes the necessary requirements to passively measure end-to-end quality and to monitor them via applicable ways. Measuring end-to-end quality in passive ways is necessary for Service Providers (SPs) who provide transport to users. However, the standards do not define the measurement and monitoring of a network, which is helpful when the SPs want to know the quality of their end- to-end traffic. Therefore, measurement and monitoring standards need to be defined. 1.1. Requirements notation The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Kikuchi, et al. Expires January 9, 2009 [Page 3] Internet-Draft draft-kikuchi-passive-measure-reqs-00.txt Jul 2008 2. Service Model Figure 1 shows that SP X and SP Y provide a transport between user A and user B using some ISPs. Let SP X and SP Y "Transport Service Providers" (TSPs) here because they should be distinguished from the intermediate ISPs. The users construct an application over the transport. The TSPs may apply two or more routes to provide one transport. USER A ................. Application ................ USER B | | (SLA) (SLA) | | TSP X >>................ Transport ................>> TSP Y | | *-> ISP 1_1 -> ISP 1_2 -> ... -> ISP 1_n1 ->* | | *-> ISP 2_1 -> ISP 2_2 -> ... -> ISP 2_n2 ->* : : *-> ISP m_1 -> ISP m_2 -> ... -> ISP m_nm ->* Figure 1: Service Model The TSPs maintain reachability and some required quality of the transport of IP datagrams to users. There must be Service Level Agreements (SLAs) in the contract between the TSPs and thier users. The SLAs specify the level that the TSPs must maintain, which are sets of measurable characteristics such as total unavailable time in a month, loss of packets and some qualities for real time applications. Kikuchi, et al. Expires January 9, 2009 [Page 4] Internet-Draft draft-kikuchi-passive-measure-reqs-00.txt Jul 2008 3. Motivations TSPs need to know the quality of their traffic in order to know whether the traffic in a normal state or not. The measured quality could be important information to trace down the cause of the trouble when an application is not working properly. Without the necessary information, it is difficult for TSPs to determine whether problems come from the user, the TSPs, or the intermediate ISPs. The quality measurement is specially required by TSPs when they have SLAs to their customers. They must be aware of the status of underlying traffic well and must report it as an evidence of quality to the users. TSPs also need to know the quality of a transport when they have multiple paths to serve the transport. TSPs may be able to serve an appropriate transport to users by selecting a better quality path. In addition, the TSPs may be able to distribute the load of a transport to different paths. Kikuchi, et al. Expires January 9, 2009 [Page 5] Internet-Draft draft-kikuchi-passive-measure-reqs-00.txt Jul 2008 4. Requirements This section describes each requirement necessary to measure one-way end-to-end quality for TSPs. The quality should be measured for transports in operation because the measured quality is used to maintain the transports to report regarding to the SLA and to select the best path. The measurement would be used not only for testing and benchmarking but also for the daily operational tool. Therefore, the requirements are from operational points of view. 4.1. Active vs. Passive There are two ways to measure the quality of transports, one is active and the other is passive. Active measurement uses additional probing packets to determine the quality of the tranports. Passive measurement uses the traffic packets to measure quality. From the TSPs point of view, passive measurement should be supported. Because SLAs should refer to the users' transports, the measurement should be determined passively rather than actively. 4.2. Quality Evaluation The standard that define a passive measurement of transports must contain two elements, one is `WHAT' type of quality the protocol measure, or `metrics', and the other is `HOW' the protocol evaluate the quality. The most basic metric is to detect whether the packets in a transport are in-sequence or out-of-sequence. Measurement of types of out-of- sequence packets are also basic metrics, such as lost, duplication and reordering in a transport. It is required to disable the measurement function for avoiding the measurement overhead in case when TSPs need not to measure the quality. See also the discussion in the Section 4.4. 4.3. Getting Quality Information The measurement mechanisms must define how to monitor the result of the quality of transports, such as SNMP [RFC3411]. The parameters used in the measurement mechanisms might be modified by TSPs' operators. Moreover, they may notify exceptional situations and illegal operations to the operators. Kikuchi, et al. Expires January 9, 2009 [Page 6] Internet-Draft draft-kikuchi-passive-measure-reqs-00.txt Jul 2008 4.4. Overhead Consideration Protocol designers should take into account the computing and space costs of the implementations where the standard defines the measurement and monitoring. This includes overhead of traffic transmission, which may reflect the cost of equipment introductions and operational expenses. The designers should not adopt non- scalable mechanisms and should pay particular attention to resource consumption sensitive protocols such as mobile protocols. We should adopt a simplified determination in some cases when both a precise complex determination and a simpler one exist. Sometimes it is sufficient for operators to show an approximate degree different from the normal operation rather than a precise state. Kikuchi, et al. Expires January 9, 2009 [Page 7] Internet-Draft draft-kikuchi-passive-measure-reqs-00.txt Jul 2008 5. Security Considerations Not yet. Kikuchi, et al. Expires January 9, 2009 [Page 8] Internet-Draft draft-kikuchi-passive-measure-reqs-00.txt Jul 2008 Appendix A. Acknowledgements The authors would like to thank for helpful discussions in TEReCo 2.0 research project sponsored in part by the ministry of internal affairs and communications Japan (SCOPE 072309007). Kikuchi, et al. Expires January 9, 2009 [Page 9] Internet-Draft draft-kikuchi-passive-measure-reqs-00.txt Jul 2008 6. References 6.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 6.2. Informative References [RFC3411] Harrington, D., Presuhn, R., and B. Wijnen, "An Architecture for Describing Simple Network Management Protocol (SNMP) Management Frameworks", STD 62, RFC 3411, December 2002. Kikuchi, et al. Expires January 9, 2009 [Page 10] Internet-Draft draft-kikuchi-passive-measure-reqs-00.txt Jul 2008 Authors' Addresses Yutaka Kikuchi Kochi University of Technology 306B Research Collaboration Center 185 Miyanokuchi, Tosayamada-cho Kami-shi, Kochi 782-0003 JP Phone: +81-887-57-2068 Email: yu@kikuken.org Satoru Matsushima Softbank Telecom Corp. 1-9-1 Higashi-Shinbashi Minato-ku, Tokyo JP Email: satoru@ft.solteria.net Ken-ichi Nagami Intec Netcore Inc. 1-3-3 Shin-suna Koto-ku, Tokyo JP Phone: +81-3-5565-5069 Email: nagami@inetcore.com Satoshi Uda Japan Advanced Institute of Science and Technology 1-1 Asahi-dai Nomi-shi, Ishikawa-ken 923-1292 JP Email: zin@jaist.ac.jp Kikuchi, et al. Expires January 9, 2009 [Page 11] Internet-Draft draft-kikuchi-passive-measure-reqs-00.txt Jul 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). 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