| < draft-ietf-ippm-2330-update-01.txt | draft-ietf-ippm-2330-update-02.txt > | |||
|---|---|---|---|---|
| Network Working Group J. Fabini | Network Working Group J. Fabini | |||
| Internet-Draft Vienna University of Technology | Internet-Draft Vienna University of Technology | |||
| Intended status: Informational A. Morton | Updates: 2330 (if approved) A. Morton | |||
| Expires: April 18, 2014 AT&T Labs | Intended status: Informational AT&T Labs | |||
| October 15, 2013 | Expires: August 11, 2014 February 7, 2014 | |||
| Advanced Stream and Sampling Framework for IPPM | Advanced Stream and Sampling Framework for IPPM | |||
| draft-ietf-ippm-2330-update-01 | draft-ietf-ippm-2330-update-02 | |||
| Abstract | Abstract | |||
| To obtain repeatable results in modern networks, test descriptions | To obtain repeatable results in modern networks, test descriptions | |||
| need an expanded stream parameter framework that also augments | need an expanded stream parameter framework that also augments | |||
| aspects specified as Type-P for test packets. This memo proposes to | aspects specified as Type-P for test packets. This memo proposes to | |||
| update the IP Performance Metrics (IPPM) Framework with advanced | update the IP Performance Metrics (IPPM) Framework with advanced | |||
| considerations for measurement methodology and testing. The existing | considerations for measurement methodology and testing. The existing | |||
| framework mostly assumes deterministic connectivity, and that a | framework mostly assumes deterministic connectivity, and that a | |||
| single test stream will represent the characteristics of the path | single test stream will represent the characteristics of the path | |||
| skipping to change at page 1, line 33 ¶ | skipping to change at page 1, line 33 ¶ | |||
| network features may dominate the measured performance. This memo | network features may dominate the measured performance. This memo | |||
| describes new stream parameters for both network characterization and | describes new stream parameters for both network characterization and | |||
| support of application design using IPPM metrics. | support of application design using IPPM metrics. | |||
| Requirements Language | Requirements Language | |||
| The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | |||
| "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this | "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this | |||
| document are to be interpreted as described in RFC 2119 [RFC2119]. | document are to be interpreted as described in RFC 2119 [RFC2119]. | |||
| Status of this Memo | Status of This Memo | |||
| This Internet-Draft is submitted in full conformance with the | This Internet-Draft is submitted in full conformance with the | |||
| provisions of BCP 78 and BCP 79. | provisions of BCP 78 and BCP 79. | |||
| Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
| working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
| Drafts is at http://datatracker.ietf.org/drafts/current/. | Drafts is at http://datatracker.ietf.org/drafts/current/. | |||
| Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
| material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
| This Internet-Draft will expire on April 18, 2014. | This Internet-Draft will expire on August 11, 2014. | |||
| Copyright Notice | Copyright Notice | |||
| Copyright (c) 2013 IETF Trust and the persons identified as the | Copyright (c) 2014 IETF Trust and the persons identified as the | |||
| document authors. All rights reserved. | document authors. All rights reserved. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
| (http://trustee.ietf.org/license-info) in effect on the date of | (http://trustee.ietf.org/license-info) in effect on the date of | |||
| publication of this document. Please review these documents | publication of this document. Please review these documents | |||
| carefully, as they describe your rights and restrictions with respect | carefully, as they describe your rights and restrictions with respect | |||
| to this document. Code Components extracted from this document must | to this document. Code Components extracted from this document must | |||
| include Simplified BSD License text as described in Section 4.e of | include Simplified BSD License text as described in Section 4.e of | |||
| the Trust Legal Provisions and are provided without warranty as | the Trust Legal Provisions and are provided without warranty as | |||
| described in the Simplified BSD License. | described in the Simplified BSD License. | |||
| Table of Contents | Table of Contents | |||
| 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 | |||
| 1.1. Definition: Reactive Path Behavior . . . . . . . . . . . . 3 | 1.1. Definition: Reactive Path Behavior . . . . . . . . . . . 3 | |||
| 2. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 | 2. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 | |||
| 3. New or Revised Stream Parameters . . . . . . . . . . . . . . . 4 | 3. New or Revised Stream Parameters . . . . . . . . . . . . . . 5 | |||
| 3.1. Test Packet Type-P . . . . . . . . . . . . . . . . . . . . 6 | 3.1. Test Packet Type-P . . . . . . . . . . . . . . . . . . . 6 | |||
| 3.1.1. Multiple Test Packet Lengths . . . . . . . . . . . . . 6 | 3.1.1. Multiple Test Packet Lengths . . . . . . . . . . . . 6 | |||
| 3.1.2. Test Packet Payload Content Optimization . . . . . . . 6 | 3.1.2. Test Packet Payload Content Optimization . . . . . . 7 | |||
| 3.2. Packet History . . . . . . . . . . . . . . . . . . . . . . 7 | 3.2. Packet History . . . . . . . . . . . . . . . . . . . . . 7 | |||
| 3.3. Access Technology Change . . . . . . . . . . . . . . . . . 7 | 3.3. Access Technology Change . . . . . . . . . . . . . . . . 7 | |||
| 3.4. Time-Slotted Randomness Cancellation . . . . . . . . . . . 7 | 3.4. Time-Slotted Randomness Cancellation . . . . . . . . . . 8 | |||
| 4. Quality of Metrics and Methodologies . . . . . . . . . . . . . 9 | 4. Quality of Metrics and Methodologies . . . . . . . . . . . . 9 | |||
| 4.1. Repeatability . . . . . . . . . . . . . . . . . . . . . . 9 | 4.1. Repeatability . . . . . . . . . . . . . . . . . . . . . . 9 | |||
| 4.2. Continuity . . . . . . . . . . . . . . . . . . . . . . . . 10 | 4.2. Continuity . . . . . . . . . . . . . . . . . . . . . . . 10 | |||
| 4.3. Actionable . . . . . . . . . . . . . . . . . . . . . . . . 10 | 4.3. Actionable . . . . . . . . . . . . . . . . . . . . . . . 11 | |||
| 4.4. Conservative . . . . . . . . . . . . . . . . . . . . . . . 11 | 4.4. Conservative . . . . . . . . . . . . . . . . . . . . . . 11 | |||
| 4.5. Spatial and Temporal Composition . . . . . . . . . . . . . 12 | 4.5. Spatial and Temporal Composition . . . . . . . . . . . . 12 | |||
| 4.6. Poisson Sampling . . . . . . . . . . . . . . . . . . . . . 12 | 4.6. Poisson Sampling . . . . . . . . . . . . . . . . . . . . 12 | |||
| 5. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 12 | 5. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 12 | |||
| 6. Security Considerations . . . . . . . . . . . . . . . . . . . 12 | 6. Security Considerations . . . . . . . . . . . . . . . . . . . 13 | |||
| 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 | 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 | |||
| 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13 | 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 | |||
| 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 | 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 | |||
| 9.1. Normative References . . . . . . . . . . . . . . . . . . . 13 | 9.1. Normative References . . . . . . . . . . . . . . . . . . 13 | |||
| 9.2. Informative References . . . . . . . . . . . . . . . . . . 14 | 9.2. Informative References . . . . . . . . . . . . . . . . . 14 | |||
| Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14 | Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 | |||
| 1. Introduction | 1. Introduction | |||
| The IETF IP Performance Metrics (IPPM) working group first created a | The IETF IP Performance Metrics (IPPM) working group first created a | |||
| framework for metric development in [RFC2330]. This framework has | framework for metric development in [RFC2330]. This framework has | |||
| stood the test of time and enabled development of many fundamental | stood the test of time and enabled development of many fundamental | |||
| metrics, while only being updated once in a specific area [RFC5835]. | metrics, while only being updated once in a specific area [RFC5835]. | |||
| The IPPM framework [RFC2330] generally relies on several assumptions, | The IPPM framework [RFC2330] generally relies on several assumptions, | |||
| one of which is not explicitly stated but assumed: lightly loaded | one of which is not explicitly stated but assumed: lightly loaded | |||
| skipping to change at page 4, line 12 ¶ | skipping to change at page 4, line 8 ¶ | |||
| characteristics *change* according to prior observations of the | characteristics *change* according to prior observations of the | |||
| packet flow of interest (at the reactive host or link). Therefore, | packet flow of interest (at the reactive host or link). Therefore, | |||
| reactive path behavior is nominally deterministic with respect to the | reactive path behavior is nominally deterministic with respect to the | |||
| flow of interest. Other flows or traffic load conditions may result | flow of interest. Other flows or traffic load conditions may result | |||
| in additional performance-affecting reactions, but these are external | in additional performance-affecting reactions, but these are external | |||
| to the characteristics of the flow of interest. | to the characteristics of the flow of interest. | |||
| In practice, a sender may not have absolute control of the ingress | In practice, a sender may not have absolute control of the ingress | |||
| packet stream characteristics at a reactive host or link, but this | packet stream characteristics at a reactive host or link, but this | |||
| does not change the deterministic reactions present there. If we | does not change the deterministic reactions present there. If we | |||
| measure a path and the arrival characteristics at the reactive host/ | measure a path, the arrival characteristics at the reactive host/link | |||
| link depend on both the sending characteristics and the transfer | are determined by the sending characteristics and the transfer | |||
| characteristics of intervening hosts and links, then the reaction | characteristics of intervening hosts and links. Identical traffic | |||
| will appear less deterministic owing to the noise in the pattern at | patterns at the sending host might generate distinct patterns at the | |||
| the reactive host/link. | reactive host's/link's input due to impairments in the intermediate | |||
| subpath. The reactive host/link is expected to provide deterministic | ||||
| response on identical input patterns. | ||||
| Other than the size of the payload at the layer of interest and the | Other than the size of the payload at the layer of interest and the | |||
| header itself, packet content does not influence the measurement. | header itself, packet content does not influence the measurement. | |||
| Reactive behavior at the IP layer is not influenced by the TCP ports | Reactive behavior at the IP layer is not influenced by the TCP ports | |||
| in use, for example. Therefore, the indication of reactive behavior | in use, for example. Therefore, the indication of reactive behavior | |||
| must include the layer at which measurements are instituted. | must include the layer at which measurements are instituted. | |||
| Examples include links with Active/In-active state detectors, and | Examples include links with Active/In-active state detectors, and | |||
| hosts or links that revise their traffic serving and forwarding rates | hosts or links that revise their traffic serving and forwarding rates | |||
| (up or down) based on packet arrival history. | (up or down) based on packet arrival history. | |||
| skipping to change at page 4, line 38 ¶ | skipping to change at page 4, line 36 ¶ | |||
| Although difficult to handle from a measurement point of view, | Although difficult to handle from a measurement point of view, | |||
| reactive paths entities are usually designed to improve overall | reactive paths entities are usually designed to improve overall | |||
| network performance and user experience, for example by making | network performance and user experience, for example by making | |||
| capacity available to an active user. Reactive behavior may be an | capacity available to an active user. Reactive behavior may be an | |||
| artifact of solutions to allocate scarce resources according to the | artifact of solutions to allocate scarce resources according to the | |||
| demands of users, thus it is an important problem to solve for | demands of users, thus it is an important problem to solve for | |||
| measurement and other disciplines, such as application design. | measurement and other disciplines, such as application design. | |||
| 2. Scope | 2. Scope | |||
| The scope of this memo is to describe useful stream parameters in | The purpose of this memo is to foster repeatable measurement results | |||
| addition to the information in Section 11.1 of [RFC2330] and | in modern networks by highlighting the key aspects of test streams | |||
| described in [RFC3432] for periodic streams. The purpose is to | and packets and make them part of the IPPM performance metric | |||
| foster repeatable measurement results in modern networks by | framework. | |||
| highlighting the key aspects of test streams and packets and make | ||||
| them part of the IPPM performance metric framework. | The scope is to update key sections of [RFC2330], adding | |||
| considerations that will aid the development of new measurement | ||||
| methodologies intended for today's IP networks. Specifically, this | ||||
| memo describes useful stream parameters in addition to the | ||||
| information in Section 11.1 of [RFC2330] and described in [RFC3432] | ||||
| for periodic streams. | ||||
| The memo also provides new considerations to update the criteria for | ||||
| metrics in section 4 of [RFC2330], the measurement methodology in | ||||
| section 6.2 of [RFC2330], and other topics related to the quality of | ||||
| metrics and methods (see section 4). | ||||
| Other topics in [RFC2330] which might be updated or augmented are | ||||
| deferred to future work. This includes the topics of passive and | ||||
| various forms of of hybrid active/passive measurements. | ||||
| 3. New or Revised Stream Parameters | 3. New or Revised Stream Parameters | |||
| There are several areas where measurement methodology definition and | There are several areas where measurement methodology definition and | |||
| test result interpretation will benefit from an increased | test result interpretation will benefit from an increased | |||
| understanding of the stream characteristics and the (possibly | understanding of the stream characteristics and the (possibly | |||
| unknown) network condition that influence the measured metrics. | unknown) network condition that influence the measured metrics. | |||
| 1. Network treatment depends on the fullest extent on the "packet of | 1. Network treatment depends on the fullest extent on the "packet of | |||
| Type-P" definition in [RFC2330], and has for some time. | Type-P" definition in [RFC2330], and has for some time. | |||
| skipping to change at page 6, line 30 ¶ | skipping to change at page 6, line 41 ¶ | |||
| Many instances of network characterization using IPPM metrics have | Many instances of network characterization using IPPM metrics have | |||
| relied on a single test packet length. When testing to assess | relied on a single test packet length. When testing to assess | |||
| application performance or an aggregate of traffic, benchmarking | application performance or an aggregate of traffic, benchmarking | |||
| methods have used a range of fixed lengths and frequently augmented | methods have used a range of fixed lengths and frequently augmented | |||
| fixed size tests with a mixture of sizes, or IMIX as described in | fixed size tests with a mixture of sizes, or IMIX as described in | |||
| [RFC6985]. | [RFC6985]. | |||
| Test packet length influences delay measurements, in that the IPPM | Test packet length influences delay measurements, in that the IPPM | |||
| one-way delay metric [RFC2679] includes serialization time in its | one-way delay metric [RFC2679] includes serialization time in its | |||
| first-bit to last bit time stamping requirements. However, different | first-bit to last bit time stamping requirements. However, different | |||
| sizes can have a larger effect on link delay and link delay variation | sizes can have a larger influence on link delay and link delay | |||
| than serialization would explain alone. This effect can be non- | variation than serialization would explain alone. This effect can be | |||
| linear and change the instantaneous network performance when a | non-linear and change the instantaneous network performance when a | |||
| different size is used, or the performance of packets following the | different size is used, or the performance of packets following the | |||
| size change. | size change. | |||
| Repeatability is a main measurement methodology goal as stated in | Repeatability is a main measurement methodology goal as stated in | |||
| section 6.2 of [RFC2330]. To eliminate packet length as a potential | section 6.2 of [RFC2330]. To eliminate packet length as a potential | |||
| measurement uncertainty factor, successive measurements must use | measurement uncertainty factor, successive measurements must use | |||
| identical traffic patterns. In practice a combination of random | identical traffic patterns. In practice a combination of random | |||
| payload and random start time can yield representative results as | payload and random start time can yield representative results as | |||
| illustrated in [IRR]. | illustrated in [IRR]. | |||
| 3.1.2. Test Packet Payload Content Optimization | 3.1.2. Test Packet Payload Content Optimization | |||
| The aim for efficient network resource use has resulted in deployment | The aim for efficient network resource use has resulted in deployment | |||
| of server-only or client-server lossless or lossy payload compression | of server-only or client-server lossless or lossy payload compression | |||
| techniques on some links or paths. These optimizers attempt to | techniques on some links or paths. These optimizers attempt to | |||
| compress high-volume traffic in order to reduce network load. Files | compress high-volume traffic in order to reduce network load. Files | |||
| are analyzed by application-layer parsers and parts (like comments) | are analyzed by application-layer parsers, and parts (like comments) | |||
| might be dropped. Although typically acting on HTTP or JPEG files, | might be dropped. Although typically acting on HTTP or JPEG files, | |||
| compression might affect measurement packets, too. In particular | compression might affect measurement packets, too. In particular, | |||
| measurement packets are qualified for efficient compression when they | measurement packets are qualified for efficient compression when they | |||
| use standard plain-text payload. | use standard plain-text payload. | |||
| IPPM-conforming measurements should add packet payload content as a | IPPM-conforming measurements should add packet payload content as a | |||
| Type-P parameter which can help to improve measurement determinism. | Type-P parameter which can help to improve measurement determinism. | |||
| Some packet payloads are more susceptible to compression than others, | Some packet payloads are more susceptible to compression than others, | |||
| but optimizers in the measurement path can be out ruled by using | but optimizers in the measurement path can be out ruled by using | |||
| incompressible packet payload. This payload content could be either | incompressible packet payload. This payload content could be either | |||
| generated by a random device or by using part of a compressed file | generated by a random device or by using part of a compressed file | |||
| (e.g., a part of a ZIP compressed archive). | (e.g., a part of a ZIP compressed archive). | |||
| 3.2. Packet History | 3.2. Packet History | |||
| Recent packet history and instantaneous data rate influence | Recent packet history and instantaneous data rate influence | |||
| measurement results for reactive links supporting on-demand capacity | measurement results for reactive links supporting on-demand capacity | |||
| allocation. Measurement uncertainty may be reduced by knowledge of | allocation. Measurement uncertainty may be reduced by knowledge of | |||
| measurement packet history and total host load. Additionally, small | measurement packet history and total host load. Additionally, small | |||
| changes in history, e.g., because of lost packets along the path, can | changes in history, e.g., because of lost packets along the path, can | |||
| be the cause of large performance variations. | be the cause of large performance variations. | |||
| For instance delay in reactive 3G networks like High Speed Packet | For instance, delay in reactive 3G networks like High Speed Packet | |||
| Access (HSPA) depends to a large extent on the test traffic data | Access (HSPA) depends to a large extent on the test traffic data | |||
| rate. The reactive resource allocation strategy in these networks | rate. The reactive resource allocation strategy in these networks | |||
| affects the uplink direction in particular. Small changes in data | affects the uplink direction in particular. Small changes in data | |||
| rate can be the reason of more than 200% increase in delay, depending | rate can be the reason of more than 200% increase in delay, depending | |||
| on the specific packet size. | on the specific packet size. | |||
| 3.3. Access Technology Change | 3.3. Access Technology Change | |||
| [RFC2330] discussed the scenario of multi-homed hosts. If hosts | [RFC2330] discussed the scenario of multi-homed hosts. If hosts | |||
| become aware of access technology changes (e.g., because of IP | become aware of access technology changes (e.g., because of IP | |||
| address changes or lower layer information) and make this information | address changes or lower layer information) and make this information | |||
| available, measurement methodologies can use this information to | available, measurement methodologies can use this information to | |||
| improve measurement representativeness and relevance. | improve measurement representativeness and relevance. | |||
| However, today's various access network technologies can present the | However, today's various access network technologies can present the | |||
| same physical interface to the host. A host may or may not become | same physical interface to the host. A host may or may not become | |||
| aware when its access technology changes on such an interface. | aware when its access technology changes on such an interface. | |||
| Measurements for paths which support on-demand capacity allocation | Measurements for paths which support on-demand capacity allocation | |||
| are therefore challenging in that it is difficult to differentiate | are therefore challenging, in that it is difficult to differentiate | |||
| between access technology changes (e.g., because of mobility) and | between access technology changes (e.g., because of mobility) and | |||
| reactive path behavior (e.g., because of data rate change). | reactive path behavior (e.g., because of data rate change). | |||
| 3.4. Time-Slotted Randomness Cancellation | 3.4. Time-Slotted Randomness Cancellation | |||
| Time-Slotted operation of path entities - interfaces, routers or | Time-Slotted operation of path entities - interfaces, routers or | |||
| links - in a network path is a particular challenge for measurements, | links - in a network path is a particular challenge for measurements, | |||
| especially if the time slot period is substantial. The central | especially if the time slot period is substantial. The central | |||
| observation as an extension to Poisson stream sampling in [RFC2330] | observation as an extension to Poisson stream sampling in [RFC2330] | |||
| is that the first such time-slotted component cancels unbiased | is that the first such time-slotted component cancels unbiased | |||
| skipping to change at page 10, line 4 ¶ | skipping to change at page 10, line 13 ¶ | |||
| tests are hyper-sensitive to differences in the mean of | tests are hyper-sensitive to differences in the mean of | |||
| distributions), and recognize the original findings of [RFC2330] | distributions), and recognize the original findings of [RFC2330] | |||
| regarding excess sample sizes. | regarding excess sample sizes. | |||
| One way to view the reliance on identical conditions is to view it as | One way to view the reliance on identical conditions is to view it as | |||
| a challenge: how few parameters and path conditions need to be | a challenge: how few parameters and path conditions need to be | |||
| controlled and still produce repeatable methods/measurements? | controlled and still produce repeatable methods/measurements? | |||
| Although the [RFC6808] test plan documented numerical criteria for | Although the [RFC6808] test plan documented numerical criteria for | |||
| equivalence, we cannot specify the exact numerical criteria for | equivalence, we cannot specify the exact numerical criteria for | |||
| repeatability *in general*. The process in the BCP [RFC6576] and | repeatability *in general*. The process in the BCP [RFC6576] and | |||
| statistics in [RFC6808] have been used successfully, and the | statistics in [RFC6808] have been used successfully, and the | |||
| numerical criteria to declare a metric repeatable should be agreed by | numerical criteria to declare a metric repeatable should be agreed by | |||
| all interested parties prior to measurement. | all interested parties prior to measurement. | |||
| We revise the definition slightly, as follows: | We revise the definition slightly, as follows: | |||
| "A methodology for a metric should have the property that it is | "A methodology for a metric should have the property that it is | |||
| repeatable: if the methodology is used multiple times under identical | repeatable: if the methodology is used multiple times under identical | |||
| conditions, the methods should produce equivalent measurement | conditions, the methods should produce equivalent measurement | |||
| results." | results." | |||
| skipping to change at page 12, line 43 ¶ | skipping to change at page 13, line 4 ¶ | |||
| methodologies is highly challenging and sometimes impossible in | methodologies is highly challenging and sometimes impossible in | |||
| reactive paths. Measurements in paths with demand-driven allocation | reactive paths. Measurements in paths with demand-driven allocation | |||
| strategies must use a prototypical application packet stream to infer | strategies must use a prototypical application packet stream to infer | |||
| a specific application's performance. Measurement repetition with | a specific application's performance. Measurement repetition with | |||
| unbiased network and flow states (e.g., by rebooting measurement | unbiased network and flow states (e.g., by rebooting measurement | |||
| hosts) can help to avoid interference with periodic network behavior, | hosts) can help to avoid interference with periodic network behavior, | |||
| randomness being a mandatory feature for avoiding correlation with | randomness being a mandatory feature for avoiding correlation with | |||
| network timing. Inferring the path performance between one | network timing. Inferring the path performance between one | |||
| measurement session or packet stream and other streams with alternate | measurement session or packet stream and other streams with alternate | |||
| characteristics is generally discouraged with reactive paths because | characteristics is generally discouraged with reactive paths because | |||
| of the huge set of global parameters which have influence | of the huge set of global parameters which have influence on | |||
| instantaneous path performance. | instantaneous path performance. | |||
| 6. Security Considerations | 6. Security Considerations | |||
| The security considerations that apply to any active measurement of | The security considerations that apply to any active measurement of | |||
| live paths are relevant here as well. See [RFC4656] and [RFC5357]. | live paths are relevant here as well. See [RFC4656] and [RFC5357]. | |||
| 7. IANA Considerations | 7. IANA Considerations | |||
| This memo makes no requests of IANA. | This memo makes no requests of IANA. | |||
| 8. Acknowledgements | 8. Acknowledgements | |||
| The authors thank Rudiger Geib, Matt Mathis and Konstantinos | The authors thank Rudiger Geib, Matt Mathis and Konstantinos | |||
| Pentikousis for their helpful comments on this draft. | Pentikousis for their helpful comments on this memo, and Ann Cerveny | |||
| for her editorial review and comments that helped to improve | ||||
| readability overall. | ||||
| 9. References | 9. References | |||
| 9.1. Normative References | 9.1. Normative References | |||
| [RFC2026] Bradner, S., "The Internet Standards Process -- Revision | [RFC2026] Bradner, S., "The Internet Standards Process -- Revision | |||
| 3", BCP 9, RFC 2026, October 1996. | 3", BCP 9, RFC 2026, October 1996. | |||
| [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | |||
| Requirement Levels", BCP 14, RFC 2119, March 1997. | Requirement Levels", BCP 14, RFC 2119, March 1997. | |||
| [RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, | [RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, | |||
| "Framework for IP Performance Metrics", RFC 2330, | "Framework for IP Performance Metrics", RFC 2330, May | |||
| May 1998. | 1998. | |||
| [RFC2679] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way | [RFC2679] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way | |||
| Delay Metric for IPPM", RFC 2679, September 1999. | Delay Metric for IPPM", RFC 2679, September 1999. | |||
| [RFC2680] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way | [RFC2680] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way | |||
| Packet Loss Metric for IPPM", RFC 2680, September 1999. | Packet Loss Metric for IPPM", RFC 2680, September 1999. | |||
| [RFC3432] Raisanen, V., Grotefeld, G., and A. Morton, "Network | [RFC3432] Raisanen, V., Grotefeld, G., and A. Morton, "Network | |||
| performance measurement with periodic streams", RFC 3432, | performance measurement with periodic streams", RFC 3432, | |||
| November 2002. | November 2002. | |||
| skipping to change at page 14, line 22 ¶ | skipping to change at page 14, line 32 ¶ | |||
| [RFC6703] Morton, A., Ramachandran, G., and G. Maguluri, "Reporting | [RFC6703] Morton, A., Ramachandran, G., and G. Maguluri, "Reporting | |||
| IP Network Performance Metrics: Different Points of View", | IP Network Performance Metrics: Different Points of View", | |||
| RFC 6703, August 2012. | RFC 6703, August 2012. | |||
| 9.2. Informative References | 9.2. Informative References | |||
| [IBD] Fabini, J., Karner, W., Wallentin, L., and T. Baumgartner, | [IBD] Fabini, J., Karner, W., Wallentin, L., and T. Baumgartner, | |||
| "The Illusion of Being Deterministic - Application-Level | "The Illusion of Being Deterministic - Application-Level | |||
| Considerations on Delay in 3G HSPA Networks", Lecture | Considerations on Delay in 3G HSPA Networks", Lecture | |||
| Notes in Computer Science, Springer, Volume 5550, 2009, | Notes in Computer Science, Springer, Volume 5550, 2009, pp | |||
| pp 301-312 , May 2009. | 301-312 , May 2009. | |||
| [IRR] Fabini, J., Wallentin, L., and P. Reichl, "The Importance | [IRR] Fabini, J., Wallentin, L., and P. Reichl, "The Importance | |||
| of Being Really Random: Methodological Aspects of IP-Layer | of Being Really Random: Methodological Aspects of IP-Layer | |||
| 2G and 3G Network Delay Assessment", ICC'09 Proceedings of | 2G and 3G Network Delay Assessment", ICC'09 Proceedings of | |||
| the 2009 IEEE International Conference on | the 2009 IEEE International Conference on Communications, | |||
| Communications, doi: 10.1109/ICC.2009.5199514, June 2009. | doi: 10.1109/ICC.2009.5199514, June 2009. | |||
| [RFC3148] Mathis, M. and M. Allman, "A Framework for Defining | [RFC3148] Mathis, M. and M. Allman, "A Framework for Defining | |||
| Empirical Bulk Transfer Capacity Metrics", RFC 3148, | Empirical Bulk Transfer Capacity Metrics", RFC 3148, July | |||
| July 2001. | 2001. | |||
| [RFC6808] Ciavattone, L., Geib, R., Morton, A., and M. Wieser, "Test | [RFC6808] Ciavattone, L., Geib, R., Morton, A., and M. Wieser, "Test | |||
| Plan and Results Supporting Advancement of RFC 2679 on the | Plan and Results Supporting Advancement of RFC 2679 on the | |||
| Standards Track", RFC 6808, December 2012. | Standards Track", RFC 6808, December 2012. | |||
| [RFC6985] Morton, A., "IMIX Genome: Specification of Variable Packet | [RFC6985] Morton, A., "IMIX Genome: Specification of Variable Packet | |||
| Sizes for Additional Testing", RFC 6985, July 2013. | Sizes for Additional Testing", RFC 6985, July 2013. | |||
| [TSRC] Fabini, J. and M. Abmayer, "Delay Measurement Methodology | [TSRC] Fabini, J. and M. Abmayer, "Delay Measurement Methodology | |||
| Revisited: Time-slotted Randomness Cancellation", IEEE | Revisited: Time-slotted Randomness Cancellation", IEEE | |||
| Transactions on Instrumentation and Measurement doi: | Transactions on Instrumentation and Measurement | |||
| 10.1109/TIM.2013.2263914, October 2013. | doi:10.1109/TIM.2013.2263914, October 2013. | |||
| Authors' Addresses | Authors' Addresses | |||
| Joachim Fabini | Joachim Fabini | |||
| Vienna University of Technology | Vienna University of Technology | |||
| Gusshausstrasse 25/E389 | Gusshausstrasse 25/E389 | |||
| Vienna, 1040 | Vienna 1040 | |||
| Austria | Austria | |||
| Phone: +43 1 58801 38813 | Phone: +43 1 58801 38813 | |||
| Fax: +43 1 58801 38898 | Fax: +43 1 58801 38898 | |||
| Email: Joachim.Fabini@tuwien.ac.at | Email: Joachim.Fabini@tuwien.ac.at | |||
| URI: http://www.tc.tuwien.ac.at/about-us/staff/joachim-fabini/ | URI: http://www.tc.tuwien.ac.at/about-us/staff/joachim-fabini/ | |||
| Al Morton | Al Morton | |||
| AT&T Labs | AT&T Labs | |||
| 200 Laurel Avenue South | 200 Laurel Avenue South | |||
| End of changes. 22 change blocks. | ||||
| 64 lines changed or deleted | 82 lines changed or added | |||
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