draft-ietf-bmwg-igp-dataplane-conv-term-23.txt | rfc6412.txt | |||
---|---|---|---|---|

Network Working Group S. Poretsky | Internet Engineering Task Force (IETF) S. Poretsky | |||

Internet-Draft Allot Communications | Request for Comments: 6412 Allot Communications | |||

Intended status: Informational B. Imhoff | Category: Informational B. Imhoff | |||

Expires: August 13, 2011 Juniper Networks | ISSN: 2070-1721 F5 Networks | |||

K. Michielsen | K. Michielsen | |||

Cisco Systems | Cisco Systems | |||

February 16, 2011 | November 2011 | |||

Terminology for Benchmarking Link-State IGP Data Plane Route Convergence | Terminology for Benchmarking Link-State IGP Data-Plane Route Convergence | |||

draft-ietf-bmwg-igp-dataplane-conv-term-23 | ||||

Abstract | Abstract | |||

This document describes the terminology for benchmarking link-state | This document describes the terminology for benchmarking link-state | |||

Interior Gateway Protocol (IGP) route convergence. The terminology | Interior Gateway Protocol (IGP) route convergence. The terminology | |||

is to be used for benchmarking IGP convergence time through | is to be used for benchmarking IGP convergence time through | |||

externally observable (black box) data plane measurements. The | externally observable (black-box) data-plane measurements. The | |||

terminology can be applied to any link-state IGP, such as | terminology can be applied to any link-state IGP, such as IS-IS and | |||

Intermediate System to Intermediate System (IS-IS) and Open Shortest | OSPF. | |||

Path First (OSPF). | ||||

Status of this Memo | ||||

This Internet-Draft is submitted in full conformance with the | Status of This Memo | |||

provisions of BCP 78 and BCP 79. | ||||

Internet-Drafts are working documents of the Internet Engineering | This document is not an Internet Standards Track specification; it is | |||

Task Force (IETF). Note that other groups may also distribute | published for informational purposes. | |||

working documents as Internet-Drafts. The list of current Internet- | ||||

Drafts is at http://datatracker.ietf.org/drafts/current/. | ||||

Internet-Drafts are draft documents valid for a maximum of six months | This document is a product of the Internet Engineering Task Force | |||

and may be updated, replaced, or obsoleted by other documents at any | (IETF). It represents the consensus of the IETF community. It has | |||

time. It is inappropriate to use Internet-Drafts as reference | received public review and has been approved for publication by the | |||

material or to cite them other than as "work in progress." | Internet Engineering Steering Group (IESG). Not all documents | |||

approved by the IESG are a candidate for any level of Internet | ||||

Standard; see Section 2 of RFC 5741. | ||||

This Internet-Draft will expire on August 13, 2011. | Information about the current status of this document, any errata, | |||

and how to provide feedback on it may be obtained at | ||||

http://www.rfc-editor.org/info/rfc6412. | ||||

Copyright Notice | Copyright Notice | |||

Copyright (c) 2011 IETF Trust and the persons identified as the | Copyright (c) 2011 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 | |||

skipping to change at page 3, line 9 | skipping to change at page 3, line 9 | |||

the copyright in such materials, this document may not be modified | the copyright in such materials, this document may not be modified | |||

outside the IETF Standards Process, and derivative works of it may | outside the IETF Standards Process, and derivative works of it may | |||

not be created outside the IETF Standards Process, except to format | not be created outside the IETF Standards Process, except to format | |||

it for publication as an RFC or to translate it into languages other | it for publication as an RFC or to translate it into languages other | |||

than English. | than English. | |||

Table of Contents | Table of Contents | |||

1. Introduction and Scope . . . . . . . . . . . . . . . . . . . . 4 | 1. Introduction and Scope . . . . . . . . . . . . . . . . . . . . 4 | |||

2. Existing Definitions . . . . . . . . . . . . . . . . . . . . . 4 | 2. Existing Definitions . . . . . . . . . . . . . . . . . . . . . 4 | |||

3. Term Definitions . . . . . . . . . . . . . . . . . . . . . . . 4 | 3. Term Definitions . . . . . . . . . . . . . . . . . . . . . . . 5 | |||

3.1. Convergence Types . . . . . . . . . . . . . . . . . . . . 4 | 3.1. Convergence Types . . . . . . . . . . . . . . . . . . . . 5 | |||

3.1.1. Route Convergence . . . . . . . . . . . . . . . . . . 5 | 3.1.1. Route Convergence . . . . . . . . . . . . . . . . . . 5 | |||

3.1.2. Full Convergence . . . . . . . . . . . . . . . . . . . 5 | 3.1.2. Full Convergence . . . . . . . . . . . . . . . . . . . 5 | |||

3.2. Instants . . . . . . . . . . . . . . . . . . . . . . . . . 6 | 3.2. Instants . . . . . . . . . . . . . . . . . . . . . . . . . 6 | |||

3.2.1. Traffic Start Instant . . . . . . . . . . . . . . . . 6 | 3.2.1. Traffic Start Instant . . . . . . . . . . . . . . . . 6 | |||

3.2.2. Convergence Event Instant . . . . . . . . . . . . . . 6 | 3.2.2. Convergence Event Instant . . . . . . . . . . . . . . 6 | |||

3.2.3. Convergence Recovery Instant . . . . . . . . . . . . . 7 | 3.2.3. Convergence Recovery Instant . . . . . . . . . . . . . 7 | |||

3.2.4. First Route Convergence Instant . . . . . . . . . . . 7 | 3.2.4. First Route Convergence Instant . . . . . . . . . . . 8 | |||

3.3. Transitions . . . . . . . . . . . . . . . . . . . . . . . 8 | 3.3. Transitions . . . . . . . . . . . . . . . . . . . . . . . 8 | |||

3.3.1. Convergence Event Transition . . . . . . . . . . . . . 8 | 3.3.1. Convergence Event Transition . . . . . . . . . . . . . 8 | |||

3.3.2. Convergence Recovery Transition . . . . . . . . . . . 9 | 3.3.2. Convergence Recovery Transition . . . . . . . . . . . 9 | |||

3.4. Interfaces . . . . . . . . . . . . . . . . . . . . . . . . 9 | 3.4. Interfaces . . . . . . . . . . . . . . . . . . . . . . . . 10 | |||

3.4.1. Local Interface . . . . . . . . . . . . . . . . . . . 9 | 3.4.1. Local Interface . . . . . . . . . . . . . . . . . . . 10 | |||

3.4.2. Remote Interface . . . . . . . . . . . . . . . . . . . 9 | 3.4.2. Remote Interface . . . . . . . . . . . . . . . . . . . 10 | |||

3.4.3. Preferred Egress Interface . . . . . . . . . . . . . . 10 | 3.4.3. Preferred Egress Interface . . . . . . . . . . . . . . 10 | |||

3.4.4. Next-Best Egress Interface . . . . . . . . . . . . . . 10 | 3.4.4. Next-Best Egress Interface . . . . . . . . . . . . . . 11 | |||

3.5. Benchmarking Methods . . . . . . . . . . . . . . . . . . . 11 | 3.5. Benchmarking Methods . . . . . . . . . . . . . . . . . . . 11 | |||

3.5.1. Rate-Derived Method . . . . . . . . . . . . . . . . . 11 | 3.5.1. Rate-Derived Method . . . . . . . . . . . . . . . . . 11 | |||

3.5.2. Loss-Derived Method . . . . . . . . . . . . . . . . . 13 | 3.5.2. Loss-Derived Method . . . . . . . . . . . . . . . . . 14 | |||

3.5.3. Route-Specific Loss-Derived Method . . . . . . . . . . 14 | 3.5.3. Route-Specific Loss-Derived Method . . . . . . . . . . 15 | |||

3.6. Benchmarks . . . . . . . . . . . . . . . . . . . . . . . . 15 | 3.6. Benchmarks . . . . . . . . . . . . . . . . . . . . . . . . 17 | |||

3.6.1. Full Convergence Time . . . . . . . . . . . . . . . . 15 | 3.6.1. Full Convergence Time . . . . . . . . . . . . . . . . 17 | |||

3.6.2. First Route Convergence Time . . . . . . . . . . . . . 16 | 3.6.2. First Route Convergence Time . . . . . . . . . . . . . 18 | |||

3.6.3. Route-Specific Convergence Time . . . . . . . . . . . 17 | 3.6.3. Route-Specific Convergence Time . . . . . . . . . . . 18 | |||

3.6.4. Loss-Derived Convergence Time . . . . . . . . . . . . 18 | 3.6.4. Loss-Derived Convergence Time . . . . . . . . . . . . 20 | |||

3.6.5. Route Loss of Connectivity Period . . . . . . . . . . 19 | 3.6.5. Route Loss of Connectivity Period . . . . . . . . . . 21 | |||

3.6.6. Loss-Derived Loss of Connectivity Period . . . . . . . 20 | 3.6.6. Loss-Derived Loss of Connectivity Period . . . . . . . 22 | |||

3.7. Measurement Terms . . . . . . . . . . . . . . . . . . . . 21 | 3.7. Measurement Terms . . . . . . . . . . . . . . . . . . . . 23 | |||

3.7.1. Convergence Event . . . . . . . . . . . . . . . . . . 21 | 3.7.1. Convergence Event . . . . . . . . . . . . . . . . . . 23 | |||

3.7.2. Convergence Packet Loss . . . . . . . . . . . . . . . 21 | 3.7.2. Convergence Packet Loss . . . . . . . . . . . . . . . 23 | |||

3.7.3. Connectivity Packet Loss . . . . . . . . . . . . . . . 22 | 3.7.3. Connectivity Packet Loss . . . . . . . . . . . . . . . 24 | |||

3.7.4. Packet Sampling Interval . . . . . . . . . . . . . . . 22 | 3.7.4. Packet Sampling Interval . . . . . . . . . . . . . . . 24 | |||

3.7.5. Sustained Convergence Validation Time . . . . . . . . 23 | 3.7.5. Sustained Convergence Validation Time . . . . . . . . 25 | |||

3.7.6. Forwarding Delay Threshold . . . . . . . . . . . . . . 24 | 3.7.6. Forwarding Delay Threshold . . . . . . . . . . . . . . 26 | |||

3.8. Miscellaneous Terms . . . . . . . . . . . . . . . . . . . 24 | 3.8. Miscellaneous Terms . . . . . . . . . . . . . . . . . . . 26 | |||

3.8.1. Impaired Packet . . . . . . . . . . . . . . . . . . . 24 | 3.8.1. Impaired Packet . . . . . . . . . . . . . . . . . . . 26 | |||

4. Security Considerations . . . . . . . . . . . . . . . . . . . 24 | 4. Security Considerations . . . . . . . . . . . . . . . . . . . 27 | |||

5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25 | 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 27 | |||

6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 25 | 6. Normative References . . . . . . . . . . . . . . . . . . . . . 27 | |||

7. Normative References . . . . . . . . . . . . . . . . . . . . . 25 | ||||

Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 26 | ||||

1. Introduction and Scope | 1. Introduction and Scope | |||

This document is a companion to [Po11m] which the methodology to be | This document is a companion to [Po11m], which contains the | |||

used for benchmarking link-state Interior Gateway Protocol (IGP) | methodology to be used for benchmarking link-state Interior Gateway | |||

Convergence by observing the data plane. The purpose of this | Protocol (IGP) convergence by observing the data plane. The purpose | |||

document is to introduce new terms required to complete execution of | of this document is to introduce new terms required to complete | |||

the Link-State IGP Data Plane Route Convergence methodology [Po11m]. | execution of the Link-State IGP Data-Plane Route Convergence | |||

methodology [Po11m]. | ||||

IGP convergence time is measured by observing the dataplane through | IGP convergence time is measured by observing the data plane through | |||

the Device Under Test (DUT) at the Tester. The methodology and | the Device Under Test (DUT) at the Tester. The methodology and | |||

terminology to be used for benchmarking IGP Convergence can be | terminology to be used for benchmarking IGP convergence can be | |||

applied to IPv4 and IPv6 traffic and link-state IGPs such as | applied to IPv4 and IPv6 traffic and link-state IGPs such as | |||

Intermediate System to Intermediate System (IS-IS) [Ca90][Ho08], Open | Intermediate System to Intermediate System (IS-IS) [Ca90][Ho08], Open | |||

Shortest Path First (OSPF) [Mo98][Co08], and others. | Shortest Path First (OSPF) [Mo98] [Co08], and others. | |||

2. Existing Definitions | 2. Existing Definitions | |||

This document uses existing terminology defined in other IETF | This document uses existing terminology defined in other IETF | |||

documents. Examples include, but are not limited to: | documents. Examples include, but are not limited to: | |||

Throughput [Ref.[Br91], section 3.17] | Throughput [Br91], Section 3.17 | |||

Offered Load [Ref.[Ma98], section 3.5.2] | Offered Load [Ma98], Section 3.5.2 | |||

Forwarding Rate [Ref.[Ma98], section 3.6.1] | Forwarding Rate [Ma98], Section 3.6.1 | |||

Device Under Test (DUT) [Ref.[Ma98], section 3.1.1] | Device Under Test (DUT) [Ma98], Section 3.1.1 | |||

System Under Test (SUT) [Ref.[Ma98], section 3.1.2] | System Under Test (SUT) [Ma98], Section 3.1.2 | |||

Out-of-Order Packet [Ref.[Po06], section 3.3.4] | Out-of-Order Packet [Po06], Section 3.3.4 | |||

Duplicate Packet [Ref.[Po06], section 3.3.5] | Duplicate Packet [Po06], Section 3.3.5 | |||

Stream [Ref.[Po06], section 3.3.2] | Stream [Po06], Section 3.3.2 | |||

Forwarding Delay [Ref.[Po06], section 3.2.4] | Forwarding Delay [Po06], Section 3.2.4 | |||

IP Packet Delay Variation (IPDV) [Ref.[De02], section 1.2] | IP Packet Delay Variation (IPDV) [De02], Section 1.2 | |||

Loss Period [Ref.[Ko02], section 4] | Loss Period [Ko02], Section 4 | |||

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | The keywords "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 BCP 14, RFC 2119 | document are to be interpreted as described in BCP 14, RFC 2119 | |||

[Br97]. RFC 2119 defines the use of these key words to help make the | [Br97]. RFC 2119 defines the use of these keywords to help make the | |||

intent of standards track documents as clear as possible. While this | intent of Standards Track documents as clear as possible. While this | |||

document uses these keywords, this document is not a standards track | document uses these keywords, this document is not a Standards Track | |||

document. | document. | |||

3. Term Definitions | 3. Term Definitions | |||

3.1. Convergence Types | 3.1. Convergence Types | |||

3.1.1. Route Convergence | 3.1.1. Route Convergence | |||

Definition: | Definition: | |||

The process of updating all components of the router, including the | The process of updating all components of the router, including | |||

Routing Information Base (RIB) and Forwarding Information Base (FIB), | the Routing Information Base (RIB) and Forwarding Information Base | |||

along with software and hardware tables, with the most recent route | (FIB), along with software and hardware tables, with the most | |||

change(s) such that forwarding for a route entry is successful on the | recent route change(s) such that forwarding for a route entry is | |||

Next-Best Egress Interface [Section 3.4.4]. | successful on the Next-Best Egress Interface (Section 3.4.4). | |||

Discussion: | Discussion: | |||

In general IGP convergence does not necessarily result in a change in | In general, IGP convergence does not necessarily result in a | |||

forwarding. But the test cases in [Po11m] are specified such that | change in forwarding. But the test cases in [Po11m] are specified | |||

the IGP convergence results in a change of egress interface for the | such that the IGP convergence results in a change of egress | |||

measurement dataplane traffic. Due to this property of the test case | interface for the measurement data-plane traffic. Due to this | |||

specifications, Route Convergence can be observed externally by the | property of the test case specifications, Route Convergence can be | |||

rerouting of the measurement dataplane traffic to the Next-best | observed externally by the rerouting of the measurement data-plane | |||

Egress Interface [Section 3.4.4]. | traffic to the Next-Best Egress Interface (Section 3.4.4). | |||

Measurement Units: N/A | Measurement Units: | |||

N/A | ||||

See Also: | See Also: | |||

Next-Best Egress Interface, Full Convergence | Next-Best Egress Interface, Full Convergence | |||

3.1.2. Full Convergence | 3.1.2. Full Convergence | |||

Definition: | Definition: | |||

Route Convergence for all routes in the Forwarding Information Base | Route Convergence for all routes in the Forwarding Information | |||

(FIB). | Base (FIB). | |||

Discussion: | Discussion: | |||

In general IGP convergence does not necessarily result in a change in | In general, IGP convergence does not necessarily result in a | |||

forwarding. But the test cases in [Po11m] are specified such that | change in forwarding. But the test cases in [Po11m] are specified | |||

the IGP convergence results in a change of egress interface for the | such that the IGP convergence results in a change of egress | |||

measurement dataplane traffic. Due to this property of the test | interface for the measurement data-plane traffic. Due to this | |||

cases specifications, Full Convergence can be observed externally by | property of the test cases specifications, Full Convergence can be | |||

the rerouting of the measurement dataplane traffic to the Next-best | observed externally by the rerouting of the measurement data-plane | |||

Egress Interface [Section 3.4.4]. | traffic to the Next-Best Egress Interface (Section 3.4.4). | |||

Measurement Units: N/A | Measurement Units: | |||

N/A | ||||

See Also: | See Also: | |||

Next-Best Egress Interface, Route Convergence | Next-Best Egress Interface, Route Convergence | |||

3.2. Instants | 3.2. Instants | |||

3.2.1. Traffic Start Instant | 3.2.1. Traffic Start Instant | |||

Definition: | Definition: | |||

The time instant the Tester sends out the first data packet to the | The time instant the Tester sends out the first data packet to the | |||

Device Under Test (DUT). | DUT. | |||

Discussion: | Discussion: | |||

If using the Loss-Derived Method [Section 3.5.2] or the Route- | If using the Loss-Derived Method (Section 3.5.2) or the Route- | |||

Specific Loss-Derived Method [Section 3.5.3] to benchmark IGP | Specific Loss-Derived Method (Section 3.5.3) to benchmark IGP | |||

convergence time, and the applied Convergence Event [Section 3.7.1] | convergence time, and the applied Convergence Event | |||

does not cause instantaneous traffic loss for all routes at the | (Section 3.7.1) does not cause instantaneous traffic loss for all | |||

Convergence Event Instant [Section 3.2.2] then the Tester SHOULD | routes at the Convergence Event Instant (Section 3.2.2), then the | |||

collect a timestamp on the Traffic Start Instant in order to measure | Tester SHOULD collect a timestamp on the Traffic Start Instant in | |||

the period of time between the Traffic Start Instant and Convergence | order to measure the period of time between the Traffic Start | |||

Event Instant. | Instant and Convergence Event Instant. | |||

Measurement Units: | Measurement Units: | |||

seconds (and fractions), reported with resolution sufficient to | seconds (and fractions), reported with resolution sufficient to | |||

distinguish between different instants | distinguish between different instants | |||

See Also: | See Also: | |||

Loss-Derived Method, Route-Specific Loss-Derived Method, Convergence | Loss-Derived Method, Route-Specific Loss-Derived Method, | |||

Event, Convergence Event Instant | Convergence Event, Convergence Event Instant | |||

3.2.2. Convergence Event Instant | 3.2.2. Convergence Event Instant | |||

Definition: | Definition: | |||

The time instant that a Convergence Event [Section 3.7.1] occurs. | The time instant that a Convergence Event (Section 3.7.1) occurs. | |||

Discussion: | Discussion: | |||

If the Convergence Event [Section 3.7.1] causes instantaneous traffic | If the Convergence Event (Section 3.7.1) causes instantaneous | |||

loss on the Preferred Egress Interface [Section 3.4.3], the | traffic loss on the Preferred Egress Interface (Section 3.4.3), | |||

Convergence Event Instant is observable from the data plane as the | the Convergence Event Instant is observable from the data plane as | |||

instant that no more packets are received on the Preferred Egress | the instant that no more packets are received on the Preferred | |||

Interface. | Egress Interface. | |||

The Tester SHOULD collect a timestamp on the Convergence Event | The Tester SHOULD collect a timestamp on the Convergence Event | |||

Instant if it the Convergence Event does not cause instantaneous | Instant if the Convergence Event does not cause instantaneous | |||

traffic loss on the Preferred Egress Interface [Section 3.4.3]. | traffic loss on the Preferred Egress Interface (Section 3.4.3). | |||

Measurement Units: | Measurement Units: | |||

seconds (and fractions), reported with resolution sufficient to | seconds (and fractions), reported with resolution sufficient to | |||

distinguish between different instants | distinguish between different instants | |||

See Also: | See Also: | |||

Convergence Event, Preferred Egress Interface | Convergence Event, Preferred Egress Interface | |||

3.2.3. Convergence Recovery Instant | 3.2.3. Convergence Recovery Instant | |||

Definition: | Definition: | |||

The time instant that Full Convergence [Section 3.1.2] has completed. | The time instant that Full Convergence (Section 3.1.2) has | |||

completed. | ||||

Discussion: | Discussion: | |||

The Full Convergence completed state MUST be maintained for an | The Full Convergence completed state MUST be maintained for an | |||

interval of duration equal to the Sustained Convergence Validation | interval of duration equal to the Sustained Convergence Validation | |||

Time [Section 3.7.5] in order to validate the Convergence Recovery | Time (Section 3.7.5) in order to validate the Convergence Recovery | |||

Instant. | Instant. | |||

The Convergence Recovery Instant is observable from the data plane as | The Convergence Recovery Instant is observable from the data plane | |||

the instant the Device Under Test (DUT) forwards traffic to all | as the instant the DUT forwards traffic to all destinations over | |||

destinations over the Next-Best Egress Interface [Section 3.4.4] | the Next-Best Egress Interface (Section 3.4.4) without | |||

without impairments. | impairments. | |||

Measurement Units: | Measurement Units: | |||

seconds (and fractions), reported with resolution sufficient to | seconds (and fractions), reported with resolution sufficient to | |||

distinguish between different instants | distinguish between different instants | |||

See Also: | See Also: | |||

Sustained Convergence Validation Time, Full Convergence, Next-Best | Sustained Convergence Validation Time, Full Convergence, Next-Best | |||

Egress Interface | Egress Interface | |||

3.2.4. First Route Convergence Instant | 3.2.4. First Route Convergence Instant | |||

Definition: | Definition: | |||

The time instant the first route entry completes Route Convergence | The time instant the first route entry completes Route Convergence | |||

[Section 3.1.1] | (Section 3.1.1) | |||

Discussion: | Discussion: | |||

Any route may be the first to complete Route Convergence. The First | Any route may be the first to complete Route Convergence. The | |||

Route Convergence Instant is observable from the data plane as the | First Route Convergence Instant is observable from the data plane | |||

instant that the first packet that is not an Impaired Packet | as the instant that the first packet that is not an Impaired | |||

[Section 3.8.1] is received from the Next-Best Egress Interface | Packet (Section 3.8.1) is received from the Next-Best Egress | |||

[Section 3.4.4] or, for the test cases with Equal Cost Multi-Path | Interface (Section 3.4.4) or, for the test cases with Equal Cost | |||

(ECMP) or Parallel Links, the instant that the Forwarding Rate on the | Multi-Path (ECMP) or Parallel Links, the instant that the | |||

Next-Best Egress Interface [Section 3.4.4] starts to increase. | Forwarding Rate on the Next-Best Egress Interface (Section 3.4.4) | |||

starts to increase. | ||||

Measurement Units: | Measurement Units: | |||

seconds (and fractions), reported with resolution sufficient to | seconds (and fractions), reported with resolution sufficient to | |||

distinguish between different instants | distinguish between different instants | |||

See Also: | See Also: | |||

Route Convergence, Impaired Packet, Next-Best Egress Interface | Route Convergence, Impaired Packet, Next-Best Egress Interface | |||

3.3. Transitions | 3.3. Transitions | |||

3.3.1. Convergence Event Transition | 3.3.1. Convergence Event Transition | |||

Definition: | Definition: | |||

A time interval following a Convergence Event [Section 3.7.1] in | A time interval following a Convergence Event (Section 3.7.1) in | |||

which Forwarding Rate on the Preferred Egress Interface | which the Forwarding Rate on the Preferred Egress Interface | |||

[Section 3.4.3] gradually reduces to zero. | (Section 3.4.3) gradually reduces to zero. | |||

Discussion: | Discussion: | |||

The Forwarding Rate during a Convergence Event Transition may or may | The Forwarding Rate during a Convergence Event Transition may or | |||

not decrease linearly. | may not decrease linearly. | |||

The Forwarding Rate observed on the Device Under Test (DUT) egress | The Forwarding Rate observed on the DUT egress interface(s) may or | |||

interface(s) may or may not decrease to zero. | may not decrease to zero. | |||

The Offered Load, the number of routes, and the Packet Sampling | The Offered Load, the number of routes, and the Packet Sampling | |||

Interval [Section 3.7.4] influence the observations of the | Interval (Section 3.7.4) influence the observations of the | |||

Convergence Event Transition using the Rate-Derived Method | Convergence Event Transition using the Rate-Derived Method | |||

[Section 3.5.1]. | (Section 3.5.1). | |||

Measurement Units: seconds (and fractions) | Measurement Units: | |||

seconds (and fractions) | ||||

See Also: | See Also: | |||

Convergence Event, Preferred Egress Interface, Packet Sampling | Convergence Event, Preferred Egress Interface, Packet Sampling | |||

Interva, Rate-Derived Method | Interval, Rate-Derived Method | |||

3.3.2. Convergence Recovery Transition | 3.3.2. Convergence Recovery Transition | |||

Definition: | Definition: | |||

A time interval following the First Route Convergence Instant | A time interval following the First Route Convergence Instant | |||

[Section 3.4.4] in which Forwarding Rate on the Device Under Test | (Section 3.4.4) in which the Forwarding Rate on the DUT egress | |||

(DUT) egress interface(s) gradually increases to equal the Offered | interface(s) gradually increases to equal to the Offered Load. | |||

Load. | ||||

Discussion: | Discussion: | |||

The Forwarding Rate observed during a Convergence Recovery Transition | The Forwarding Rate observed during a Convergence Recovery | |||

may or may not increase linearly. | Transition may or may not increase linearly. | |||

The Offered Load, the number of routes, and the Packet Sampling | The Offered Load, the number of routes, and the Packet Sampling | |||

Interval [Section 3.7.4] influence the observations of the | Interval (Section 3.7.4) influence the observations of the | |||

Convergence Recovery Transition using the Rate-Derived Method | Convergence Recovery Transition using the Rate-Derived Method | |||

[Section 3.5.1]. | (Section 3.5.1). | |||

Measurement Units: seconds (and fractions) | Measurement Units: | |||

seconds (and fractions) | ||||

See Also: | See Also: | |||

First Route Convergence Instant, Packet Sampling Interva, Rate- | First Route Convergence Instant, Packet Sampling Interval, Rate- | |||

Derived Method | Derived Method | |||

3.4. Interfaces | 3.4. Interfaces | |||

3.4.1. Local Interface | 3.4.1. Local Interface | |||

Definition: | Definition: | |||

An interface on the Device Under Test (DUT). | An interface on the DUT. | |||

Discussion: | Discussion: | |||

A failure of a Local Interface indicates that the failure occurred | A failure of a Local Interface indicates that the failure occurred | |||

directly on the Device Under Test (DUT). | directly on the DUT. | |||

Measurement Units: N/A | Measurement Units: | |||

See Also: Remote Interface | N/A | |||

See Also: | ||||

Remote Interface | ||||

3.4.2. Remote Interface | 3.4.2. Remote Interface | |||

Definition: | Definition: | |||

An interface on a neighboring router that is not directly connected | An interface on a neighboring router that is not directly | |||

to any interface on the Device Under Test (DUT). | connected to any interface on the DUT. | |||

Discussion: | Discussion: | |||

A failure of a Remote Interface indicates that the failure occurred | A failure of a Remote Interface indicates that the failure | |||

on a neighbor router's interface that is not directly connected to | occurred on a neighbor router's interface that is not directly | |||

the Device Under Test (DUT). | connected to the DUT. | |||

Measurement Units: N/A | Measurement Units: | |||

See Also: Local Interface | N/A | |||

See Also: | ||||

Local Interface | ||||

3.4.3. Preferred Egress Interface | 3.4.3. Preferred Egress Interface | |||

Definition: | Definition: | |||

The outbound interface from the Device Under Test (DUT) for traffic | The outbound interface from the DUT for traffic routed to the | |||

routed to the preferred next-hop. | preferred next-hop. | |||

Discussion: | Discussion: | |||

The Preferred Egress Interface is the egress interface prior to a | The Preferred Egress Interface is the egress interface prior to a | |||

Convergence Event [Section 3.7.1]. | Convergence Event (Section 3.7.1). | |||

Measurement Units: N/A | Measurement Units: | |||

See Also: Convergence Event, Next-Best Egress Interface | N/A | |||

See Also: | ||||

Convergence Event, Next-Best Egress Interface | ||||

3.4.4. Next-Best Egress Interface | 3.4.4. Next-Best Egress Interface | |||

Definition: | Definition: | |||

The outbound interface or set of outbound interfaces in an Equal Cost | The outbound interface or set of outbound interfaces in an Equal | |||

Multipath (ECMP) set or parallel link set of the Device Under Test | Cost Multipath (ECMP) set or parallel link set of the Device Under | |||

(DUT) for traffic routed to the second-best next-hop. | Test (DUT) for traffic routed to the second-best next-hop. | |||

Discussion: | Discussion: | |||

The Next-Best Egress Interface becomes the egress interface after a | The Next-Best Egress Interface becomes the egress interface after | |||

Convergence Event [Section 3.4.4]. | a Convergence Event (Section 3.4.4). | |||

For the test cases in [Po11m] using test topologies with an ECMP set | For the test cases in [Po11m] using test topologies with an ECMP | |||

or parallel link set, the term Preferred Egress Interface refers to | set or parallel link set, the term Preferred Egress Interface | |||

all members of the link set. | refers to all members of the link set. | |||

Measurement Units: N/A | Measurement Units: | |||

See Also: Convergence Event, Preferred Egress Interface | N/A | |||

See Also: | ||||

Convergence Event, Preferred Egress Interface | ||||

3.5. Benchmarking Methods | 3.5. Benchmarking Methods | |||

3.5.1. Rate-Derived Method | 3.5.1. Rate-Derived Method | |||

Definition: | Definition: | |||

The method to calculate convergence time benchmarks from observing | The method to calculate convergence time benchmarks from observing | |||

Forwarding Rate each Packet Sampling Interval [Section 3.7.4]. | the Forwarding Rate each Packet Sampling Interval (Section 3.7.4). | |||

Discussion: | Discussion: | |||

Figure 1 shows an example of the Forwarding Rate change in time | Figure 1 shows an example of the Forwarding Rate change in time | |||

during convergence as observed when using the Rate-Derived Method. | during convergence as observed when using the Rate-Derived Method. | |||

^ Traffic Convergence | ^ Traffic Convergence | |||

Fwd | Start Recovery | Fwd | Start Recovery | |||

Rate | Instant Instant | Rate | Instant Instant | |||

| Offered ^ ^ | | Offered ^ ^ | |||

| Load --> ----------\ /----------- | | Load --> ----------\ /----------- | |||

| \ /<--- Convergence | | \ /<--- Convergence | |||

| \ Packet / Recovery | | \ Packet / Recovery | |||

| Convergence --->\ Loss / Transition | | Convergence --->\ Loss / Transition | |||

| Event \ / | | Event \ / | |||

| Transition \---------/ <-- Max Packet Loss | | Transition \---------/ <-- Max Packet Loss | |||

| | | | |||

+---------------------------------------------------------> | +---------------------------------------------------------> | |||

^ ^ time | ^ ^ time | |||

Convergence First Route | Convergence First Route | |||

Event Instant Convergence Instant | Event Instant Convergence Instant | |||

Figure 1: Rate-Derived Convergence Graph | Figure 1: Rate-Derived Convergence Graph | |||

To enable collecting statistics of Out-of-Order Packets per flow (See | To enable collecting statistics of Out-of-Order Packets per flow | |||

[Th00], Section 3) the Offered Load SHOULD consist of multiple | (see [Th00], Section 3), the Offered Load SHOULD consist of | |||

Streams [Po06] and each Stream SHOULD consist of a single flow . If | multiple Streams [Po06], and each Stream SHOULD consist of a | |||

sending multiple Streams, the measured traffic statistics for all | single flow . If sending multiple Streams, the measured traffic | |||

Streams MUST be added together. | statistics for all Streams MUST be added together. | |||

The destination addresses for the Offered Load MUST be distributed | The destination addresses for the Offered Load MUST be distributed | |||

such that all routes or a statistically representative subset of all | such that all routes or a statistically representative subset of | |||

routes are matched and each of these routes is offered an equal share | all routes are matched and each of these routes is offered an | |||

of the Offered Load. It is RECOMMENDED to send traffic to all | equal share of the Offered Load. It is RECOMMENDED to send | |||

routes, but a statistically representative subset of all routes can | traffic to all routes, but a statistically representative subset | |||

be used if required. | of all routes can be used if required. | |||

At least one packet per route for all routes matched in the Offered | At least one packet per route for all routes matched in the | |||

Load MUST be offered to the DUT within each Packet Sampling Interval. | Offered Load MUST be offered to the DUT within each Packet | |||

For maximum accuracy the value for the Packet Sampling Interval | Sampling Interval. For maximum accuracy, the value of the Packet | |||

SHOULD be as small as possible, but the presence of IP Packet Delay | Sampling Interval SHOULD be as small as possible, but the presence | |||

Variation (IPDV) [De02] may enforce using a larger Packet Sampling | of IP Packet Delay Variation (IPDV) [De02] may require that a | |||

Interval. | larger Packet Sampling Interval be used. | |||

The Offered Load, IPDV, the number of routes, and the Packet Sampling | The Offered Load, IPDV, the number of routes, and the Packet | |||

Interval influence the observations for the Rate-Derived Method. It | Sampling Interval influence the observations for the Rate-Derived | |||

may be difficult to identify the different convergence time instants | Method. It may be difficult to identify the different convergence | |||

in the Rate-Derived Convergence Graph. For example, it is possible | time instants in the Rate-Derived Convergence Graph. For example, | |||

that a Convergence Event causes the Forwarding Rate to drop to zero, | it is possible that a Convergence Event causes the Forwarding Rate | |||

while this may not be observed in the Forwarding Rate measurements if | to drop to zero, while this may not be observed in the Forwarding | |||

the Packet Sampling Interval is too large. | Rate measurements if the Packet Sampling Interval is too large. | |||

IPDV causes fluctuations in the number of received packets during | IPDV causes fluctuations in the number of received packets during | |||

each Packet Sampling Interval. To account for the presence of IPDV | each Packet Sampling Interval. To account for the presence of | |||

in determining if a convergence instant has been reached, Forwarding | IPDV in determining if a convergence instant has been reached, | |||

Delay SHOULD be observed during each Packet Sampling Interval. The | Forwarding Delay SHOULD be observed during each Packet Sampling | |||

minimum and maximum number of packets expected in a Packet Sampling | Interval. The minimum and maximum number of packets expected in a | |||

Interval in presence of IPDV can be calculated with Equation 1. | Packet Sampling Interval in presence of IPDV can be calculated | |||

with Equation 1. | ||||

number of packets expected in a Packet Sampling Interval | number of packets expected in a Packet Sampling Interval | |||

in presence of IP Packet Delay Variation | in presence of IP Packet Delay Variation | |||

= expected number of packets without IP Packet Delay Variation | = expected number of packets without IP Packet Delay Variation | |||

+/-( (maxDelay - minDelay) * Offered Load) | +/-( (maxDelay - minDelay) * Offered Load) | |||

with minDelay and maxDelay the minimum resp. maximum Forwarding Delay | where minDelay and maxDelay indicate (respectively) the minimum and | |||

of packets received during the Packet Sampling Interval | maximum Forwarding Delay of packets received during the Packet | |||

Sampling Interval | ||||

Equation 1 | Equation 1 | |||

To determine if a convergence instant has been reached the number of | To determine if a convergence instant has been reached, the number | |||

packets received in a Packet Sampling Interval is compared with the | of packets received in a Packet Sampling Interval is compared with | |||

range of expected number of packets calculated in Equation 1. | the range of expected number of packets calculated in Equation 1. | |||

If packets are going over multiple ECMP members and one or more of | If packets are going over multiple ECMP members and one or more of | |||

the members has failed then the number of received packets during | the members has failed, then the number of received packets during | |||

each Packet Sampling Interval may vary, even excluding presence of | each Packet Sampling Interval may vary, even excluding presence of | |||

IPDV. To prevent fluctuation of the number of received packets | IPDV. To prevent fluctuation of the number of received packets | |||

during each Packet Sampling Interval for this reason, the Packet | during each Packet Sampling Interval for this reason, the Packet | |||

Sampling Interval duration SHOULD be a whole multiple of the time | Sampling Interval duration SHOULD be a whole multiple of the time | |||

between two consecutive packets sent to the same destination. | between two consecutive packets sent to the same destination. | |||

Metrics measured at the Packet Sampling Interval MUST include | Metrics measured at the Packet Sampling Interval MUST include | |||

Forwarding Rate and Impaired Packet count. | Forwarding Rate and Impaired Packet count. | |||

To measure convergence time benchmarks for Convergence Events | To measure convergence time benchmarks for Convergence Events | |||

[Section 3.7.1] that do not cause instantaneous traffic loss for all | (Section 3.7.1) that do not cause instantaneous traffic loss for | |||

routes at the Convergence Event Instant, the Tester SHOULD collect a | all routes at the Convergence Event Instant, the Tester SHOULD | |||

timestamp of the Convergence Event Instant [Section 3.2.2] and the | collect a timestamp of the Convergence Event Instant | |||

Tester SHOULD observe Forwarding Rate separately on the Next-Best | (Section 3.2.2), and the Tester SHOULD observe Forwarding Rate | |||

Egress Interface. | separately on the Next-Best Egress Interface. | |||

Since the Rate-Derived Method does not distinguish between individual | Since the Rate-Derived Method does not distinguish between | |||

traffic destinations, it SHOULD NOT be used for any route specific | individual traffic destinations, it SHOULD NOT be used for any | |||

measurements. Therefor Rate-Derived Method SHOULD NOT be used to | route specific measurements. Therefore, the Rate-Derived Method | |||

benchmark Route Loss of Connectivity Period [Section 3.6.5]. | SHOULD NOT be used to benchmark Route Loss of Connectivity Period | |||

(Section 3.6.5). | ||||

Measurement Units: N/A | Measurement Units: | |||

N/A | ||||

See Also: | See Also: | |||

Packet Sampling Interval, Convergence Event, Convergence Event | Packet Sampling Interval, Convergence Event, Convergence Event | |||

Instant, Next-Best Egress Interface, Route Loss of Connectivity | Instant, Next-Best Egress Interface, Route Loss of Connectivity | |||

Period | Period | |||

3.5.2. Loss-Derived Method | 3.5.2. Loss-Derived Method | |||

Definition: | Definition: | |||

The method to calculate the Loss-Derived Convergence Time | The method to calculate the Loss-Derived Convergence Time | |||

[Section 3.6.4] and Loss-Derived Loss of Connectivity Period | (Section 3.6.4) and Loss-Derived Loss of Connectivity Period | |||

[Section 3.6.6] benchmarks from the amount of Impaired Packets | (Section 3.6.6) benchmarks from the amount of Impaired Packets | |||

[Section 3.8.1]. | (Section 3.8.1). | |||

Discussion: | Discussion: | |||

To enable collecting statistics of Out-of-Order Packets per flow (See | To enable collecting statistics of Out-of-Order Packets per flow | |||

[Th00], Section 3) the Offered Load SHOULD consist of multiple | (see [Th00], Section 3), the Offered Load SHOULD consist of | |||

Streams [Po06] and each Stream SHOULD consist of a single flow . If | multiple Streams [Po06], and each Stream SHOULD consist of a | |||

sending multiple Streams, the measured traffic statistics for all | single flow . If sending multiple Streams, the measured traffic | |||

Streams MUST be added together. | statistics for all Streams MUST be added together. | |||

The destination addresses for the Offered Load MUST be distributed | The destination addresses for the Offered Load MUST be distributed | |||

such that all routes or a statistically representative subset of all | such that all routes or a statistically representative subset of | |||

routes are matched and each of these routes is offered an equal share | all routes are matched and each of these routes is offered an | |||

of the Offered Load. It is RECOMMENDED to send traffic to all | equal share of the Offered Load. It is RECOMMENDED to send | |||

routes, but a statistically representative subset of all routes can | traffic to all routes, but a statistically representative subset | |||

be used if required. | of all routes can be used if required. | |||

Loss-Derived Method SHOULD always be combined with Rate-Derived | Loss-Derived Method SHOULD always be combined with the Rate- | |||

Method in order to observe Full Convergence completion. The total | Derived Method in order to observe Full Convergence completion. | |||

amount of Convergence Packet Loss is collected after Full Convergence | The total amount of Convergence Packet Loss is collected after | |||

completion. | Full Convergence completion. | |||

To measure convergence time and loss of connectivity benchmarks for | To measure convergence time and loss of connectivity benchmarks | |||

Convergence Events that cause instantaneous traffic loss for all | for Convergence Events that cause instantaneous traffic loss for | |||

routes at the Convergence Event Instant, the Tester SHOULD observe | all routes at the Convergence Event Instant, the Tester SHOULD | |||

Impaired Packet count on all DUT egress interfaces (see Connectivity | observe the Impaired Packet count on all DUT egress interfaces | |||

Packet Loss [Section 3.7.3]). | (see Connectivity Packet Loss (Section 3.7.3)). | |||

To measure convergence time benchmarks for Convergence Events that do | To measure convergence time benchmarks for Convergence Events that | |||

not cause instantaneous traffic loss for all routes at the | do not cause instantaneous traffic loss for all routes at the | |||

Convergence Event Instant, the Tester SHOULD collect timestamps of | Convergence Event Instant, the Tester SHOULD collect timestamps of | |||

the Start Traffic Instant and of the Convergence Event Instant, and | the Start Traffic Instant and of the Convergence Event Instant, | |||

the Tester SHOULD observe Impaired Packet count separately on the | and the Tester SHOULD observe Impaired Packet count separately on | |||

Next-Best Egress Interface (See Convergence Packet Loss | the Next-Best Egress Interface (see Convergence Packet Loss | |||

[Section 3.7.2]). | (Section 3.7.2)). | |||

Since Loss-Derived Method does not distinguish between traffic | Since Loss-Derived Method does not distinguish between traffic | |||

destinations and the Impaired Packet statistics are only collected | destinations and the Impaired Packet statistics are only collected | |||

after Full Convergence completion, this method can only be used to | after Full Convergence completion, this method can only be used to | |||

measure average values over all routes. For these reasons Loss- | measure average values over all routes. For these reasons, Loss- | |||

Derived Method can only be used to benchmark Loss-Derived Convergence | Derived Method can only be used to benchmark Loss-Derived | |||

Time [Section 3.6.4] and Loss-Derived Loss of Connectivity Period | Convergence Time (Section 3.6.4) and Loss-Derived Loss of | |||

[Section 3.6.6]. | Connectivity Period (Section 3.6.6). | |||

Note that the Loss-Derived Method measures an average over all | Note that the Loss-Derived Method measures an average over all | |||

routes, including the routes that may not be impacted by the | routes, including the routes that may not be impacted by the | |||

Convergence Event, such as routes via non-impacted members of ECMP or | Convergence Event, such as routes via non-impacted members of ECMP | |||

parallel links. | or parallel links. | |||

Measurement Units: N/A | Measurement Units: | |||

N/A | ||||

See Also: | See Also: | |||

Loss-Derived Convergence Time, Loss-Derived Loss of Connectivity | Loss-Derived Convergence Time, Loss-Derived Loss of Connectivity | |||

Period, Connectivity Packet Loss, Convergence Packet Loss | Period, Connectivity Packet Loss, Convergence Packet Loss | |||

3.5.3. Route-Specific Loss-Derived Method | 3.5.3. Route-Specific Loss-Derived Method | |||

Definition: | Definition: | |||

The method to calculate the Route-Specific Convergence Time | The method to calculate the Route-Specific Convergence Time | |||

[Section 3.6.3] benchmark from the amount of Impaired Packets | (Section 3.6.3) benchmark from the amount of Impaired Packets | |||

[Section 3.8.1] during convergence for a specific route entry. | (Section 3.8.1) during convergence for a specific route entry. | |||

Discussion: | Discussion: | |||

To benchmark Route-Specific Convergence Time, the Tester provides an | To benchmark Route-Specific Convergence Time, the Tester provides | |||

Offered Load that consists of multiple Streams [Po06]. Each Stream | an Offered Load that consists of multiple Streams [Po06]. Each | |||

has a single destination address matching a different route entry, | Stream has a single destination address matching a different route | |||

for all routes or a statistically representative subset of all | entry, for all routes or a statistically representative subset of | |||

routes. Each Stream SHOULD consist of a single flow (See [Th00], | all routes. Each Stream SHOULD consist of a single flow (see | |||

Section 3). Convergence Packet Loss is measured for each Stream | [Th00], Section 3). Convergence Packet Loss is measured for each | |||

separately. | Stream separately. | |||

Route-Specific Loss-Derived Method SHOULD always be combined with | Route-Specific Loss-Derived Method SHOULD always be combined with | |||

Rate-Derived Method in order to observe Full Convergence completion. | the Rate-Derived Method in order to observe Full Convergence | |||

The total amount of Convergence Packet Loss [Section 3.7.2] for each | completion. The total amount of Convergence Packet Loss | |||

Stream is collected after Full Convergence completion. | (Section 3.7.2) for each Stream is collected after Full | |||

Convergence completion. | ||||

Route-Specific Loss-Derived Method is the RECOMMENDED method to | Route-Specific Loss-Derived Method is the RECOMMENDED method to | |||

measure convergence time benchmarks. | measure convergence time benchmarks. | |||

To measure convergence time and loss of connectivity benchmarks for | To measure convergence time and loss of connectivity benchmarks | |||

Convergence Events that cause instantaneous traffic loss for all | for Convergence Events that cause instantaneous traffic loss for | |||

routes at the Convergence Event Instant, the Tester SHOULD observe | all routes at the Convergence Event Instant, the Tester SHOULD | |||

Impaired Packet count on all DUT egress interfaces (see Connectivity | observe Impaired Packet count on all DUT egress interfaces (see | |||

Packet Loss [Section 3.7.3]). | Connectivity Packet Loss (Section 3.7.3)). | |||

To measure convergence time benchmarks for Convergence Events that do | To measure convergence time benchmarks for Convergence Events that | |||

not cause instantaneous traffic loss for all routes at the | do not cause instantaneous traffic loss for all routes at the | |||

Convergence Event Instant, the Tester SHOULD collect timestamps of | Convergence Event Instant, the Tester SHOULD collect timestamps of | |||

the Start Traffic Instant and of the Convergence Event Instant, and | the Start Traffic Instant and of the Convergence Event Instant, | |||

the Tester SHOULD observe packet loss separately on the Next-Best | and the Tester SHOULD observe packet loss separately on the Next- | |||

Egress Interface (See Convergence Packet Loss [Section 3.7.2]). | Best Egress Interface (see Convergence Packet Loss | |||

(Section 3.7.2)). | ||||

Since Route-Specific Loss-Derived Method uses traffic streams to | Since Route-Specific Loss-Derived Method uses traffic streams to | |||

individual routes, it observes Impaired Packet count as it would be | individual routes, it observes Impaired Packet count as it would | |||

experienced by a network user. For this reason Route-Specific Loss- | be experienced by a network user. For this reason, Route-Specific | |||

Derived Method is RECOMMENDED to measure Route-Specific Convergence | Loss-Derived Method is RECOMMENDED to measure Route-Specific | |||

Time benchmarks and Route Loss of Connectivity Period benchmarks. | Convergence Time benchmarks and Route Loss of Connectivity Period | |||

benchmarks. | ||||

Measurement Units: N/A | Measurement Units: | |||

N/A | ||||

See Also: | See Also: | |||

Route-Specific Convergence Time, Route Loss of Connectivity Period, | Route-Specific Convergence Time, Route Loss of Connectivity | |||

Connectivity Packet Loss, Convergence Packet Loss | Period, Connectivity Packet Loss, Convergence Packet Loss | |||

3.6. Benchmarks | 3.6. Benchmarks | |||

3.6.1. Full Convergence Time | 3.6.1. Full Convergence Time | |||

Definition: | Definition: | |||

The time duration of the period between the Convergence Event Instant | The time duration of the period between the Convergence Event | |||

and the Convergence Recovery Instant as observed using the Rate- | Instant and the Convergence Recovery Instant as observed using the | |||

Derived Method. | Rate-Derived Method. | |||

Discussion: | Discussion: | |||

Using the Rate-Derived Method, Full Convergence Time can be | Using the Rate-Derived Method, Full Convergence Time can be | |||

calculated as the time difference between the Convergence Event | calculated as the time difference between the Convergence Event | |||

Instant and the Convergence Recovery Instant, as shown in Equation 2. | Instant and the Convergence Recovery Instant, as shown in Equation | |||

2. | ||||

Full Convergence Time = | Full Convergence Time = | |||

Convergence Recovery Instant - Convergence Event Instant | Convergence Recovery Instant - Convergence Event Instant | |||

Equation 2 | Equation 2 | |||

The Convergence Event Instant can be derived from the Forwarding Rate | The Convergence Event Instant can be derived from the Forwarding | |||

observation or from a timestamp collected by the Tester. | Rate observation or from a timestamp collected by the Tester. | |||

For the test cases described in [Po11m], it is expected that Full | For the test cases described in [Po11m], it is expected that Full | |||

Convergence Time equals the maximum Route-Specific Convergence Time | Convergence Time equals the maximum Route-Specific Convergence | |||

when benchmarking all routes in FIB using the Route-Specific Loss- | Time when benchmarking all routes in the FIB using the Route- | |||

Derived Method. | Specific Loss-Derived Method. | |||

It is not possible to measure Full Convergence Time using the Loss- | It is not possible to measure Full Convergence Time using the | |||

Derived Method. | Loss-Derived Method. | |||

Measurement Units: seconds (and fractions) | Measurement Units: | |||

seconds (and fractions) | ||||

See Also: | See Also: | |||

Full Convergence, Rate-Derived Method, Route-Specific Loss-Derived | Full Convergence, Rate-Derived Method, Route-Specific Loss-Derived | |||

Method, Convergence Event Instant, Convergence Recovery Instant | Method, Convergence Event Instant, Convergence Recovery Instant | |||

3.6.2. First Route Convergence Time | 3.6.2. First Route Convergence Time | |||

Definition: | Definition: | |||

The duration of the period between the Convergence Event Instant and | The duration of the period between the Convergence Event Instant | |||

the First Route Convergence Instant as observed using the Rate- | and the First Route Convergence Instant as observed using the | |||

Derived Method. | Rate-Derived Method. | |||

Discussion: | Discussion: | |||

Using the Rate-Derived Method, First Route Convergence Time can be | Using the Rate-Derived Method, First Route Convergence Time can be | |||

calculated as the time difference between the Convergence Event | calculated as the time difference between the Convergence Event | |||

Instant and the First Route Convergence Instant, as shown with | Instant and the First Route Convergence Instant, as shown with | |||

Equation 3. | Equation 3. | |||

First Route Convergence Time = | First Route Convergence Time = | |||

First Route Convergence Instant - Convergence Event Instant | First Route Convergence Instant - Convergence Event Instant | |||

Equation 3 | Equation 3 | |||

The Convergence Event Instant can be derived from the Forwarding Rate | The Convergence Event Instant can be derived from the Forwarding | |||

observation or from a timestamp collected by the Tester. | Rate observation or from a timestamp collected by the Tester. | |||

For the test cases described in [Po11m], it is expected that First | For the test cases described in [Po11m], it is expected that First | |||

Route Convergence Time equals the minimum Route-Specific Convergence | Route Convergence Time equals the minimum Route-Specific | |||

Time when benchmarking all routes in FIB using the Route-Specific | Convergence Time when benchmarking all routes in the FIB using the | |||

Loss-Derived Method. | Route-Specific Loss-Derived Method. | |||

It is not possible to measure First Route Convergence Time using the | It is not possible to measure First Route Convergence Time using | |||

Loss-Derived Method. | the Loss-Derived Method. | |||

Measurement Units: seconds (and fractions) | Measurement Units: | |||

seconds (and fractions) | ||||

See Also: | See Also: | |||

Rate-Derived Method, Route-Specific Loss-Derived Method, Convergence | Rate-Derived Method, Route-Specific Loss-Derived Method, | |||

Event Instant, First Route Convergence Instant | Convergence Event Instant, First Route Convergence Instant | |||

3.6.3. Route-Specific Convergence Time | 3.6.3. Route-Specific Convergence Time | |||

Definition: | Definition: | |||

The amount of time it takes for Route Convergence to be completed for | The amount of time it takes for Route Convergence to be completed | |||

a specific route, as calculated from the amount of Impaired Packets | for a specific route, as calculated from the amount of Impaired | |||

[Section 3.8.1] during convergence for a single route entry. | Packets (Section 3.8.1) during convergence for a single route | |||

entry. | ||||

Discussion: | Discussion: | |||

Route-Specific Convergence Time can only be measured using the Route- | Route-Specific Convergence Time can only be measured using the | |||

Specific Loss-Derived Method. | Route-Specific Loss-Derived Method. | |||

If the applied Convergence Event causes instantaneous traffic loss | If the applied Convergence Event causes instantaneous traffic loss | |||

for all routes at the Convergence Event Instant, Connectivity Packet | for all routes at the Convergence Event Instant, Connectivity | |||

Loss should be observed. Connectivity Packet Loss is the combined | Packet Loss should be observed. Connectivity Packet Loss is the | |||

Impaired Packet count observed on Preferred Egress Interface and | combined Impaired Packet count observed on Preferred Egress | |||

Next-Best Egress Interface. When benchmarking Route-Specific | Interface and Next-Best Egress Interface. When benchmarking | |||

Convergence Time, Connectivity Packet Loss is measured and Equation 4 | Route-Specific Convergence Time, Connectivity Packet Loss is | |||

is applied for each measured route. The calculation is equal to | measured, and Equation 4 is applied for each measured route. The | |||

Equation 8 in Section 3.6.5. | calculation is equal to Equation 8 in Section 3.6.5. | |||

Route-Specific Convergence Time = | Route-Specific Convergence Time = | |||

Connectivity Packet Loss for specific route/Offered Load per route | Connectivity Packet Loss for specific route / Offered Load per route | |||

Equation 4 | Equation 4 | |||

If the applied Convergence Event does not cause instantaneous traffic | If the applied Convergence Event does not cause instantaneous | |||

loss for all routes at the Convergence Event Instant, then the Tester | traffic loss for all routes at the Convergence Event Instant, then | |||

SHOULD collect timestamps of the Traffic Start Instant and of the | the Tester SHOULD collect timestamps of the Traffic Start Instant | |||

Convergence Event Instant, and the Tester SHOULD observe Convergence | and of the Convergence Event Instant, and the Tester SHOULD | |||

Packet Loss separately on the Next-Best Egress Interface. When | observe Convergence Packet Loss separately on the Next-Best Egress | |||

benchmarking Route-Specific Convergence Time, Convergence Packet Loss | Interface. When benchmarking Route-Specific Convergence Time, | |||

is measured and Equation 5 is applied for each measured route. | Convergence Packet Loss is measured, and Equation 5 is applied for | |||

each measured route. | ||||

Route-Specific Convergence Time = | Route-Specific Convergence Time = | |||

Convergence Packet Loss for specific route/Offered Load per route | Convergence Packet Loss for specific route / Offered Load per route | |||

- (Convergence Event Instant - Traffic Start Instant) | - (Convergence Event Instant - Traffic Start Instant) | |||

Equation 5 | Equation 5 | |||

The Route-Specific Convergence Time benchmarks enable minimum, | The Route-Specific Convergence Time benchmarks enable minimum, | |||

maximum, average, and median convergence time measurements to be | maximum, average, and median convergence time measurements to be | |||

reported by comparing the results for the different route entries. | reported by comparing the results for the different route entries. | |||

It also enables benchmarking of convergence time when configuring a | It also enables benchmarking of convergence time when configuring | |||

priority value for route entry(ies). Since multiple Route-Specific | a priority value for the route entry or entries. Since multiple | |||

Convergence Times can be measured it is possible to have an array of | Route-Specific Convergence Times can be measured, it is possible | |||

results. The format for reporting Route-Specific Convergence Time is | to have an array of results. The format for reporting Route- | |||

provided in [Po11m]. | Specific Convergence Time is provided in [Po11m]. | |||

Measurement Units: seconds (and fractions) | Measurement Units: | |||

seconds (and fractions) | ||||

See Also: | See Also: | |||

Route-Specific Loss-Derived Method, Convergence Event, Convergence | Route-Specific Loss-Derived Method, Convergence Event, Convergence | |||

Event Instant, Convergence Packet Loss, Connectivity Packet Loss, | Event Instant, Convergence Packet Loss, Connectivity Packet Loss, | |||

Route Convergence | Route Convergence | |||

3.6.4. Loss-Derived Convergence Time | 3.6.4. Loss-Derived Convergence Time | |||

Definition: | Definition: | |||

The average Route Convergence time for all routes in the Forwarding | The average Route Convergence time for all routes in the | |||

Information Base (FIB), as calculated from the amount of Impaired | Forwarding Information Base (FIB), as calculated from the amount | |||

Packets [Section 3.8.1] during convergence. | of Impaired Packets (Section 3.8.1) during convergence. | |||

Discussion: | Discussion: | |||

Loss-Derived Convergence Time is measured using the Loss-Derived | Loss-Derived Convergence Time is measured using the Loss-Derived | |||

Method. | Method. | |||

If the applied Convergence Event causes instantaneous traffic loss | If the applied Convergence Event causes instantaneous traffic loss | |||

for all routes at the Convergence Event Instant, Connectivity Packet | for all routes at the Convergence Event Instant, Connectivity | |||

Loss [Section 3.7.3] should be observed. Connectivity Packet Loss is | Packet Loss (Section 3.7.3) should be observed. Connectivity | |||

the combined Impaired Packet count observed on Preferred Egress | Packet Loss is the combined Impaired Packet count observed on | |||

Interface and Next-Best Egress Interface. When benchmarking Loss- | Preferred Egress Interface and Next-Best Egress Interface. When | |||

Derived Convergence Time, Connectivity Packet Loss is measured and | benchmarking Loss-Derived Convergence Time, Connectivity Packet | |||

Equation 6 is applied. | Loss is measured, and Equation 6 is applied. | |||

Loss-Derived Convergence Time = | Loss-Derived Convergence Time = | |||

Connectivity Packet Loss/Offered Load | Connectivity Packet Loss / Offered Load | |||

Equation 6 | Equation 6 | |||

If the applied Convergence Event does not cause instantaneous traffic | If the applied Convergence Event does not cause instantaneous | |||

loss for all routes at the Convergence Event Instant, then the Tester | traffic loss for all routes at the Convergence Event Instant, then | |||

SHOULD collect timestamps of the Start Traffic Instant and of the | the Tester SHOULD collect timestamps of the Start Traffic Instant | |||

Convergence Event Instant and the Tester SHOULD observe Convergence | and of the Convergence Event Instant, and the Tester SHOULD | |||

Packet Loss [Section 3.7.2] separately on the Next-Best Egress | observe Convergence Packet Loss (Section 3.7.2) separately on the | |||

Interface. When benchmarking Loss-Derived Convergence Time, | Next-Best Egress Interface. When benchmarking Loss-Derived | |||

Convergence Packet Loss is measured and Equation 7 is applied. | Convergence Time, Convergence Packet Loss is measured and Equation | |||

7 is applied. | ||||

Loss-Derived Convergence Time = | Loss-Derived Convergence Time = | |||

Convergence Packet Loss/Offered Load | Convergence Packet Loss / Offered Load | |||

- (Convergence Event Instant - Traffic Start Instant) | - (Convergence Event Instant - Traffic Start Instant) | |||

Equation 7 | Equation 7 | |||

Measurement Units: seconds (and fractions) | Measurement Units: | |||

seconds (and fractions) | ||||

See Also: | See Also: | |||

Convergence Packet Loss, Connectivity Packet Loss, Route Convergence, | Convergence Packet Loss, Connectivity Packet Loss, Route | |||

Loss-Derived Method | Convergence, Loss-Derived Method | |||

3.6.5. Route Loss of Connectivity Period | 3.6.5. Route Loss of Connectivity Period | |||

Definition: | Definition: | |||

The time duration of packet impairments for a specific route entry | The time duration of packet impairments for a specific route entry | |||

following a Convergence Event until Full Convergence completion, as | following a Convergence Event until Full Convergence completion, | |||

observed using the Route-Specific Loss-Derived Method. | as observed using the Route-Specific Loss-Derived Method. | |||

Discussion: | Discussion: | |||

In general the Route Loss of Connectivity Period is not equal to the | In general, the Route Loss of Connectivity Period is not equal to | |||

Route-Specific Convergence Time. If the DUT continues to forward | the Route-Specific Convergence Time. If the DUT continues to | |||

traffic to the Preferred Egress Interface after the Convergence Event | forward traffic to the Preferred Egress Interface after the | |||

is applied then the Route Loss of Connectivity Period will be smaller | Convergence Event is applied, then the Route Loss of Connectivity | |||

than the Route-Specific Convergence Time. This is also specifically | Period will be smaller than the Route-Specific Convergence Time. | |||

the case after reversing a failure event. | This is also specifically the case after reversing a failure | |||

event. | ||||

The Route Loss of Connectivity Period may be equal to the Route- | The Route Loss of Connectivity Period may be equal to the Route- | |||

Specific Convergence Time if, as a characteristic of the Convergence | Specific Convergence Time if, as a characteristic of the | |||

Event, traffic for all routes starts dropping instantaneously on the | Convergence Event, traffic for all routes starts dropping | |||

Convergence Event Instant. See discussion in [Po11m]. | instantaneously on the Convergence Event Instant. See discussion | |||

in [Po11m]. | ||||

For the test cases described in [Po11m] the Route Loss of | For the test cases described in [Po11m], the Route Loss of | |||

Connectivity Period is expected to be a single Loss Period [Ko02]. | Connectivity Period is expected to be a single Loss Period [Ko02]. | |||

When benchmarking Route Loss of Connectivity Period, Connectivity | When benchmarking the Route Loss of Connectivity Period, | |||

Packet Loss is measured for each route and Equation 8 is applied for | Connectivity Packet Loss is measured for each route, and Equation | |||

each measured route entry. The calculation is equal to Equation 4 in | 8 is applied for each measured route entry. The calculation is | |||

Section 3.6.3. | equal to Equation 4 in Section 3.6.3. | |||

Route Loss of Connectivity Period = | Route Loss of Connectivity Period = | |||

Connectivity Packet Loss for specific route/Offered Load per route | Connectivity Packet Loss for specific route / Offered Load per route | |||

Equation 8 | Equation 8 | |||

Route Loss of Connectivity Period SHOULD be measured using Route- | Route Loss of Connectivity Period SHOULD be measured using Route- | |||

Specific Loss-Derived Method. | Specific Loss-Derived Method. | |||

Measurement Units: seconds (and fractions) | Measurement Units: | |||

seconds (and fractions) | ||||

See Also: | See Also: | |||

Route-Specific Convergence Time, Route-Specific Loss-Derived Method, | Route-Specific Convergence Time, Route-Specific Loss-Derived | |||

Connectivity Packet Loss | Method, Connectivity Packet Loss | |||

3.6.6. Loss-Derived Loss of Connectivity Period | 3.6.6. Loss-Derived Loss of Connectivity Period | |||

Definition: | Definition: | |||

The average time duration of packet impairments for all routes | The average time duration of packet impairments for all routes | |||

following a Convergence Event until Full Convergence completion, as | following a Convergence Event until Full Convergence completion, | |||

observed using the Loss-Derived Method. | as observed using the Loss-Derived Method. | |||

Discussion: | Discussion: | |||

In general the Loss-Derived Loss of Connectivity Period is not equal | In general, the Loss-Derived Loss of Connectivity Period is not | |||

to the Loss-Derived Convergence Time. If the DUT continues to | equal to the Loss-Derived Convergence Time. If the DUT continues | |||

forward traffic to the Preferred Egress Interface after the | to forward traffic to the Preferred Egress Interface after the | |||

Convergence Event is applied then the Loss-Derived Loss of | Convergence Event is applied, then the Loss-Derived Loss of | |||

Connectivity Period will be smaller than the Loss-Derived Convergence | Connectivity Period will be smaller than the Loss-Derived | |||

Time. This is also specifically the case after reversing a failure | Convergence Time. This is also specifically the case after | |||

event. | reversing a failure event. | |||

The Loss-Derived Loss of Connectivity Period may be equal to the | The Loss-Derived Loss of Connectivity Period may be equal to the | |||

Loss-Derived Convergence Time if, as a characteristic of the | Loss-Derived Convergence Time if, as a characteristic of the | |||

Convergence Event, traffic for all routes starts dropping | Convergence Event, traffic for all routes starts dropping | |||

instantaneously on the Convergence Event Instant. See discussion in | instantaneously on the Convergence Event Instant. See discussion | |||

[Po11m]. | in [Po11m]. | |||

For the test cases described in [Po11m] each route's Route Loss of | For the test cases described in [Po11m], each route's Route Loss | |||

Connectivity Period is expected to be a single Loss Period [Ko02]. | of Connectivity Period is expected to be a single Loss Period | |||

[Ko02]. | ||||

When benchmarking Loss-Derived Loss of Connectivity Period, | When benchmarking the Loss-Derived Loss of Connectivity Period, | |||

Connectivity Packet Loss is measured for all routes and Equation 9 is | Connectivity Packet Loss is measured for all routes, and Equation | |||

applied. The calculation is equal to Equation 6 in Section 3.6.4. | 9 is applied. The calculation is equal to Equation 6 in | |||

Section 3.6.4. | ||||

Loss-Derived Loss of Connectivity Period = | Loss-Derived Loss of Connectivity Period = | |||

Connectivity Packet Loss for all routes/Offered Load | Connectivity Packet Loss for all routes / Offered Load | |||

Equation 9 | Equation 9 | |||

Loss-Derived Loss of Connectivity Period SHOULD be measured using | The Loss-Derived Loss of Connectivity Period SHOULD be measured | |||

Loss-Derived Method. | using the Loss-Derived Method. | |||

Measurement Units: seconds (and fractions) | Measurement Units: | |||

seconds (and fractions) | ||||

See Also: | See Also: | |||

Loss-Derived Convergence Time, Loss-Derived Method, Connectivity | Loss-Derived Convergence Time, Loss-Derived Method, Connectivity | |||

Packet Loss | Packet Loss | |||

3.7. Measurement Terms | 3.7. Measurement Terms | |||

3.7.1. Convergence Event | 3.7.1. Convergence Event | |||

Definition: | Definition: | |||

The occurrence of an event in the network that will result in a | The occurrence of an event in the network that will result in a | |||

change in the egress interface of the Device Under Test (DUT) for | change in the egress interface of the DUT for routed packets. | |||

routed packets. | ||||

Discussion: | Discussion: | |||

All test cases in [Po11m] are defined such that a Convergence Event | All test cases in [Po11m] are defined such that a Convergence | |||

results in a change of egress interface of the DUT. Local or remote | Event results in a change of egress interface of the DUT. Local | |||

triggers that cause a route calculation which does not result in a | or remote triggers that cause a route calculation that does not | |||

change in forwarding are not considered. | result in a change in forwarding are not considered. | |||

Measurement Units: N/A | Measurement Units: | |||

See Also: Convergence Event Instant | N/A | |||

See Also: | ||||

Convergence Event Instant | ||||

3.7.2. Convergence Packet Loss | 3.7.2. Convergence Packet Loss | |||

Definition: | Definition: | |||

The number of Impaired Packets [Section 3.8.1] as observed on the | The number of Impaired Packets (Section 3.8.1) as observed on the | |||

Next-Best Egress Interface of the DUT during convergence. | Next-Best Egress Interface of the DUT during convergence. | |||

Discussion: | Discussion: | |||

An Impaired Packet is considered as a lost packet. | An Impaired Packet is considered as a lost packet. | |||

Measurement Units: number of packets | Measurement Units: | |||

number of packets | ||||

See Also: | See Also: | |||

Connectivity Packet Loss | Connectivity Packet Loss | |||

3.7.3. Connectivity Packet Loss | 3.7.3. Connectivity Packet Loss | |||

Definition: | Definition: | |||

The number of Impaired Packets observed on all DUT egress interfaces | The number of Impaired Packets observed on all DUT egress | |||

during convergence. | interfaces during convergence. | |||

Discussion: | Discussion: | |||

An Impaired Packet is considered as a lost packet. Connectivity | An Impaired Packet is considered as a lost packet. Connectivity | |||

Packet Loss is equal to Convergence Packet Loss if the Convergence | Packet Loss is equal to Convergence Packet Loss if the Convergence | |||

Event causes instantaneous traffic loss for all egress interfaces of | Event causes instantaneous traffic loss for all egress interfaces | |||

the DUT except for the Next-Best Egress Interface. | of the DUT except for the Next-Best Egress Interface. | |||

Measurement Units: number of packets | Measurement Units: | |||

number of packets | ||||

See Also: | See Also: | |||

Convergence Packet Loss | Convergence Packet Loss | |||

3.7.4. Packet Sampling Interval | 3.7.4. Packet Sampling Interval | |||

Definition: | Definition: | |||

The interval at which the Tester (test equipment) polls to make | The interval at which the Tester (test equipment) polls to make | |||

measurements for arriving packets. | measurements for arriving packets. | |||

Discussion: | Discussion: | |||

At least one packet per route for all routes matched in the Offered | At least one packet per route for all routes matched in the | |||

Load MUST be offered to the DUT within the Packet Sampling Interval. | Offered Load MUST be offered to the DUT within the Packet Sampling | |||

Metrics measured at the Packet Sampling Interval MUST include | Interval. Metrics measured at the Packet Sampling Interval MUST | |||

Forwarding Rate and received packets. | include Forwarding Rate and received packets. | |||

Packet Sampling Interval can influence the convergence graph as | Packet Sampling Interval can influence the convergence graph as | |||

observed with the Rate-Derived Method. This is particularly true | observed with the Rate-Derived Method. This is particularly true | |||

when implementations complete Full Convergence in less time than the | when implementations complete Full Convergence in less time than | |||

Packet Sampling Interval. The Convergence Event Instant and First | the Packet Sampling Interval. The Convergence Event Instant and | |||

Route Convergence Instant may not be easily identifiable and the | First Route Convergence Instant may not be easily identifiable, | |||

Rate-Derived Method may produce a larger than actual convergence | and the Rate-Derived Method may produce a larger than actual | |||

time. | convergence time. | |||

Using a small Packet Sampling Interval in the presence of IPDV [De02] | Using a small Packet Sampling Interval in the presence of IPDV | |||

may cause fluctuations of the Forwarding Rate observation and can | [De02] may cause fluctuations of the Forwarding Rate observation | |||

prevent correct observation of the different convergence time | and can prevent correct observation of the different convergence | |||

instants. | time instants. | |||

The value of the Packet Sampling Interval only contributes to the | The value of the Packet Sampling Interval only contributes to the | |||

measurement accuracy of the Rate-Derived Method. For maximum | measurement accuracy of the Rate-Derived Method. For maximum | |||

accuracy the value for the Packet Sampling Interval SHOULD be as | accuracy, the value for the Packet Sampling Interval SHOULD be as | |||

small as possible, but the presence of IPDV may enforce using a | small as possible, but the presence of IPDV may enforce using a | |||

larger Packet Sampling Interval. | larger Packet Sampling Interval. | |||

Measurement Units: seconds (and fractions) | Measurement Units: | |||

See Also: Rate-Derived Method | seconds (and fractions) | |||

See Also: | ||||

Rate-Derived Method | ||||

3.7.5. Sustained Convergence Validation Time | 3.7.5. Sustained Convergence Validation Time | |||

Definition: | Definition: | |||

The amount of time for which the completion of Full Convergence is | The amount of time for which the completion of Full Convergence is | |||

maintained without additional Impaired Packets being observed. | maintained without additional Impaired Packets being observed. | |||

Discussion: | Discussion: | |||

The purpose of the Sustained Convergence Validation Time is to | The purpose of the Sustained Convergence Validation Time is to | |||

produce convergence benchmarks protected against fluctuation in | produce convergence benchmarks protected against fluctuation in | |||

Forwarding Rate after the completion of Full Convergence is observed. | Forwarding Rate after the completion of Full Convergence is | |||

The RECOMMENDED Sustained Convergence Validation Time to be used is | observed. The RECOMMENDED Sustained Convergence Validation Time | |||

the time to send 5 consecutive packets to each destination with a | to be used is the time to send 5 consecutive packets to each | |||

minimum of 5 seconds. The Benchmarking Methodology Working Group | destination with a minimum of 5 seconds. The Benchmarking | |||

(BMWG) selected 5 seconds based upon [Br99] which recommends waiting | Methodology Working Group (BMWG) selected 5 seconds based upon | |||

2 seconds for residual frames to arrive (this is the Forwarding Delay | [Br99], which recommends waiting 2 seconds for residual frames to | |||

Threshold for the last packet sent) and 5 seconds for DUT | arrive (this is the Forwarding Delay Threshold for the last packet | |||

restabilization. | sent) and 5 seconds for DUT restabilization. | |||

Measurement Units: seconds (and fractions) | Measurement Units: | |||

seconds (and fractions) | ||||

See Also: | See Also: | |||

Full Convergence, Convergence Recovery Instant | Full Convergence, Convergence Recovery Instant | |||

3.7.6. Forwarding Delay Threshold | 3.7.6. Forwarding Delay Threshold | |||

Definition: | Definition: | |||

The maximum waiting time threshold used to distinguish between | The maximum waiting time threshold used to distinguish between | |||

packets with very long delay and lost packets that will never arrive. | packets with very long delay and lost packets that will never | |||

arrive. | ||||

Discussion: | Discussion: | |||

Applying a Forwarding Delay Threshold allows to consider packets with | Applying a Forwarding Delay Threshold allows packets with a too | |||

a too large Forwarding Delay as being lost, as is required for some | large Forwarding Delay to be considered lost, as is required for | |||

applications (e.g. voice, video, etc.). The Forwarding Delay | some applications (e.g. voice, video, etc.). The Forwarding Delay | |||

Threshold is a parameter of the methodology, and it MUST be reported. | Threshold is a parameter of the methodology, and it MUST be | |||

[Br99] recommends waiting 2 seconds for residual frames to arrive. | reported. [Br99] recommends waiting 2 seconds for residual frames | |||

to arrive. | ||||

Measurement Units: seconds (and fractions) | Measurement Units: | |||

seconds (and fractions) | ||||

See Also: | See Also: | |||

Convergence Packet Loss, Connectivity Packet Loss | Convergence Packet Loss, Connectivity Packet Loss | |||

3.8. Miscellaneous Terms | 3.8. Miscellaneous Terms | |||

3.8.1. Impaired Packet | 3.8.1. Impaired Packet | |||

Definition: | Definition: | |||

A packet that experienced at least one of the following impairments: | A packet that experienced at least one of the following | |||

loss, excessive Forwarding Delay, corruption, duplication, | impairments: loss, excessive Forwarding Delay, corruption, | |||

reordering. | duplication, reordering. | |||

Discussion: | Discussion: | |||

A lost packet, a packet with a Forwarding Delay exceeding the | A lost packet, a packet with a Forwarding Delay exceeding the | |||

Forwarding Delay Threshold, a corrupted packet, a Duplicate Packet | Forwarding Delay Threshold, a corrupted packet, a Duplicate Packet | |||

[Po06], and an Out-of-Order Packet [Po06] are Impaired Packets. | [Po06], and an Out-of-Order Packet [Po06] are Impaired Packets. | |||

Packet ordering is observed for each individual flow (See [Th00], | Packet ordering is observed for each individual flow (see [Th00], | |||

Section 3) of the Offered Load. | Section 3) of the Offered Load. | |||

Measurement Units: N/A | Measurement Units: | |||

See Also: Forwarding Delay Threshold | N/A | |||

See Also: | ||||

Forwarding Delay Threshold | ||||

4. Security Considerations | 4. Security Considerations | |||

Benchmarking activities as described in this memo are limited to | Benchmarking activities as described in this memo are limited to | |||

technology characterization using controlled stimuli in a laboratory | technology characterization using controlled stimuli in a laboratory | |||

environment, with dedicated address space and the constraints | environment, with dedicated address space and the constraints | |||

specified in the sections above. | specified in the sections above. | |||

The benchmarking network topology will be an independent test setup | The benchmarking network topology will be an independent test setup | |||

and MUST NOT be connected to devices that may forward the test | and MUST NOT be connected to devices that may forward the test | |||

traffic into a production network, or misroute traffic to the test | traffic into a production network or misroute traffic to the test | |||

management network. | management network. | |||

Further, benchmarking is performed on a "black-box" basis, relying | Further, benchmarking is performed on a "black-box" basis, relying | |||

solely on measurements observable external to the DUT/SUT. | solely on measurements observable external to the DUT/SUT. | |||

Special capabilities SHOULD NOT exist in the DUT/SUT specifically for | Special capabilities SHOULD NOT exist in the DUT/SUT specifically for | |||

benchmarking purposes. Any implications for network security arising | benchmarking purposes. Any implications for network security arising | |||

from the DUT/SUT SHOULD be identical in the lab and in production | from the DUT/SUT SHOULD be identical in the lab and in production | |||

networks. | networks. | |||

5. IANA Considerations | 5. Acknowledgements | |||

This document requires no IANA considerations. | ||||

6. Acknowledgements | ||||

Thanks to Sue Hares, Al Morton, Kevin Dubray, Ron Bonica, David Ward, | Thanks to Sue Hares, Al Morton, Kevin Dubray, Ron Bonica, David Ward, | |||

Peter De Vriendt, Anuj Dewagan, Adrian Farrel, Stewart Bryant, | Peter De Vriendt, Anuj Dewagan, Adrian Farrel, Stewart Bryant, | |||

Francis Dupont, and the Benchmarking Methodology Working Group for | Francis Dupont, and the Benchmarking Methodology Working Group for | |||

their contributions to this work. | their contributions to this work. | |||

7. Normative References | 6. Normative References | |||

[Br91] Bradner, S., "Benchmarking terminology for network | [Br91] Bradner, S., "Benchmarking terminology for network | |||

interconnection devices", RFC 1242, July 1991. | interconnection devices", RFC 1242, July 1991. | |||

[Br97] Bradner, S., "Key words for use in RFCs to Indicate | [Br97] 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. | |||

[Br99] Bradner, S. and J. McQuaid, "Benchmarking Methodology for | [Br99] Bradner, S. and J. McQuaid, "Benchmarking Methodology for | |||

Network Interconnect Devices", RFC 2544, March 1999. | Network Interconnect Devices", RFC 2544, March 1999. | |||

skipping to change at page 26, line 25 | skipping to change at page 28, line 28 | |||

[Ma98] Mandeville, R., "Benchmarking Terminology for LAN Switching | [Ma98] Mandeville, R., "Benchmarking Terminology for LAN Switching | |||

Devices", RFC 2285, February 1998. | Devices", RFC 2285, February 1998. | |||

[Mo98] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. | [Mo98] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. | |||

[Po06] Poretsky, S., Perser, J., Erramilli, S., and S. Khurana, | [Po06] Poretsky, S., Perser, J., Erramilli, S., and S. Khurana, | |||

"Terminology for Benchmarking Network-layer Traffic Control | "Terminology for Benchmarking Network-layer Traffic Control | |||

Mechanisms", RFC 4689, October 2006. | Mechanisms", RFC 4689, October 2006. | |||

[Po11m] Poretsky, S., Imhoff, B., and K. Michielsen, "Benchmarking | [Po11m] Poretsky, S., Imhoff, B., and K. Michielsen, "Benchmarking | |||

Methodology for Link-State IGP Data Plane Route | Methodology for Link-State IGP Data-Plane Route | |||

Convergence", draft-ietf-bmwg-igp-dataplane-conv-meth-23 | Convergence", RFC 6413, November 2011. | |||

(work in progress), January 2011. | ||||

[Th00] Thaler, D. and C. Hopps, "Multipath Issues in Unicast and | [Th00] Thaler, D. and C. Hopps, "Multipath Issues in Unicast and | |||

Multicast Next-Hop Selection", RFC 2991, November 2000. | Multicast Next-Hop Selection", RFC 2991, November 2000. | |||

Authors' Addresses | Authors' Addresses | |||

Scott Poretsky | Scott Poretsky | |||

Allot Communications | Allot Communications | |||

67 South Bedford Street, Suite 400 | 300 TradeCenter | |||

Burlington, MA 01803 | Woburn, MA 01801 | |||

USA | USA | |||

Phone: + 1 508 309 2179 | Phone: + 1 508 309 2179 | |||

Email: sporetsky@allot.com | EMail: sporetsky@allot.com | |||

Brent Imhoff | Brent Imhoff | |||

Juniper Networks | F5 Networks | |||

1194 North Mathilda Ave | 401 Elliott Avenue West | |||

Sunnyvale, CA 94089 | Seattle, WA 98119 | |||

USA | USA | |||

Phone: + 1 314 378 2571 | Phone: + 1 314 378 2571 | |||

Email: bimhoff@planetspork.com | EMail: bimhoff@planetspork.com | |||

Kris Michielsen | Kris Michielsen | |||

Cisco Systems | Cisco Systems | |||

6A De Kleetlaan | 6A De Kleetlaan | |||

Diegem, BRABANT 1831 | Diegem, BRABANT 1831 | |||

Belgium | Belgium | |||

Email: kmichiel@cisco.com | EMail: kmichiel@cisco.com | |||

End of changes. 200 change blocks. | ||||

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