draft-ietf-bmwg-igp-dataplane-conv-term-19.txt | draft-ietf-bmwg-igp-dataplane-conv-term-20.txt | |||
---|---|---|---|---|

Network Working Group S. Poretsky | Network Working Group S. Poretsky | |||

Internet-Draft Allot Communications | Internet-Draft Allot Communications | |||

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

Expires: April 29, 2010 Juniper Networks | Expires: September 9, 2010 Juniper Networks | |||

K. Michielsen | K. Michielsen | |||

Cisco Systems | Cisco Systems | |||

October 26, 2009 | March 8, 2010 | |||

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-19 | draft-ietf-bmwg-igp-dataplane-conv-term-20 | |||

Abstract | ||||

This document describes the terminology for benchmarking Interior | ||||

Gateway Protocol (IGP) Route Convergence. The terminology is to be | ||||

used for benchmarking IGP convergence time through externally | ||||

observable (black box) data plane measurements. The terminology can | ||||

be applied to any link-state IGP, such as ISIS and OSPF. | ||||

Status of this Memo | Status of this Memo | |||

This Internet-Draft is submitted to IETF in full conformance with the | This Internet-Draft is submitted to IETF in full conformance with the | |||

provisions of BCP 78 and BCP 79. This document may contain material | provisions of BCP 78 and BCP 79. | |||

from IETF Documents or IETF Contributions published or made publicly | ||||

available before November 10, 2008. The person(s) controlling the | ||||

copyright in some of this material may not have granted the IETF | ||||

Trust the right to allow modifications of such material outside the | ||||

IETF Standards Process. Without obtaining an adequate license from | ||||

the person(s) controlling the copyright in such materials, this | ||||

document may not be modified outside the IETF Standards Process, and | ||||

derivative works of it may not be created outside the IETF Standards | ||||

Process, except to format it for publication as an RFC or to | ||||

translate it into languages other than English. | ||||

Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||

Task Force (IETF), its areas, and its working groups. Note that | Task Force (IETF), its areas, and its working groups. Note that | |||

other groups may also distribute working documents as Internet- | other groups may also distribute working documents as Internet- | |||

Drafts. | Drafts. | |||

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." | |||

The list of current Internet-Drafts can be accessed at | The list of current Internet-Drafts can be accessed at | |||

http://www.ietf.org/ietf/1id-abstracts.txt. | http://www.ietf.org/ietf/1id-abstracts.txt. | |||

The list of Internet-Draft Shadow Directories can be accessed at | The list of Internet-Draft Shadow Directories can be accessed at | |||

http://www.ietf.org/shadow.html. | http://www.ietf.org/shadow.html. | |||

This Internet-Draft will expire on April 29, 2010. | This Internet-Draft will expire on September 9, 2010. | |||

Copyright Notice | Copyright Notice | |||

Copyright (c) 2009 IETF Trust and the persons identified as the | Copyright (c) 2010 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 in effect on the date of | Provisions Relating to IETF Documents | |||

publication of this document (http://trustee.ietf.org/license-info). | (http://trustee.ietf.org/license-info) in effect on the date of | |||

Please review these documents carefully, as they describe your rights | publication of this document. Please review these documents | |||

and restrictions with respect to this document. | carefully, as they describe your rights and restrictions with respect | |||

to this document. Code Components extracted from this document must | ||||

Abstract | include Simplified BSD License text as described in Section 4.e of | |||

the Trust Legal Provisions and are provided without warranty as | ||||

described in the BSD License. | ||||

This document describes the terminology for benchmarking Interior | This document may contain material from IETF Documents or IETF | |||

Gateway Protocol (IGP) Route Convergence. The terminology is to be | Contributions published or made publicly available before November | |||

used for benchmarking IGP convergence time through externally | 10, 2008. The person(s) controlling the copyright in some of this | |||

observable (black box) data plane measurements. The terminology can | material may not have granted the IETF Trust the right to allow | |||

be applied to any link-state IGP, such as ISIS and OSPF. | modifications of such material outside the IETF Standards Process. | |||

Without obtaining an adequate license from the person(s) controlling | ||||

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

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

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

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

than English. | ||||

Table of Contents | Table of Contents | |||

1. Introduction and Scope . . . . . . . . . . . . . . . . . . . . 4 | 1. Introduction and Scope . . . . . . . . . . . . . . . . . . . . 5 | |||

2. Existing Definitions . . . . . . . . . . . . . . . . . . . . . 4 | 2. Existing Definitions . . . . . . . . . . . . . . . . . . . . . 5 | |||

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

3.1. Convergence Types . . . . . . . . . . . . . . . . . . . . 5 | 3.1. Convergence Types . . . . . . . . . . . . . . . . . . . . 6 | |||

3.1.1. Route Convergence . . . . . . . . . . . . . . . . . . 5 | 3.1.1. Route Convergence . . . . . . . . . . . . . . . . . . 6 | |||

3.1.2. Full Convergence . . . . . . . . . . . . . . . . . . . 5 | 3.1.2. Full Convergence . . . . . . . . . . . . . . . . . . . 6 | |||

3.1.3. Network Convergence . . . . . . . . . . . . . . . . . 6 | 3.1.3. Network Convergence . . . . . . . . . . . . . . . . . 7 | |||

3.2. Instants . . . . . . . . . . . . . . . . . . . . . . . . . 6 | 3.2. Instants . . . . . . . . . . . . . . . . . . . . . . . . . 7 | |||

3.2.1. Traffic Start Instant . . . . . . . . . . . . . . . . 6 | 3.2.1. Traffic Start Instant . . . . . . . . . . . . . . . . 7 | |||

3.2.2. Convergence Event Instant . . . . . . . . . . . . . . 7 | 3.2.2. Convergence Event Instant . . . . . . . . . . . . . . 8 | |||

3.2.3. Convergence Recovery Instant . . . . . . . . . . . . . 7 | 3.2.3. Convergence Recovery Instant . . . . . . . . . . . . . 8 | |||

3.2.4. First Route Convergence Instant . . . . . . . . . . . 8 | 3.2.4. First Route Convergence Instant . . . . . . . . . . . 9 | |||

3.3. Transitions . . . . . . . . . . . . . . . . . . . . . . . 9 | 3.3. Transitions . . . . . . . . . . . . . . . . . . . . . . . 9 | |||

3.3.1. Convergence Event Transition . . . . . . . . . . . . . 9 | 3.3.1. Convergence Event Transition . . . . . . . . . . . . . 9 | |||

3.3.2. Convergence Recovery Transition . . . . . . . . . . . 9 | 3.3.2. Convergence Recovery Transition . . . . . . . . . . . 10 | |||

3.4. Interfaces . . . . . . . . . . . . . . . . . . . . . . . . 10 | 3.4. Interfaces . . . . . . . . . . . . . . . . . . . . . . . . 11 | |||

3.4.1. Local Interface . . . . . . . . . . . . . . . . . . . 10 | 3.4.1. Local Interface . . . . . . . . . . . . . . . . . . . 11 | |||

3.4.2. Remote Interface . . . . . . . . . . . . . . . . . . . 10 | 3.4.2. Remote Interface . . . . . . . . . . . . . . . . . . . 11 | |||

3.4.3. Preferred Egress Interface . . . . . . . . . . . . . . 11 | 3.4.3. Preferred Egress Interface . . . . . . . . . . . . . . 11 | |||

3.4.4. Next-Best Egress Interface . . . . . . . . . . . . . . 11 | 3.4.4. Next-Best Egress Interface . . . . . . . . . . . . . . 12 | |||

3.5. Benchmarking Methods . . . . . . . . . . . . . . . . . . . 11 | 3.5. Benchmarking Methods . . . . . . . . . . . . . . . . . . . 12 | |||

3.5.1. Rate-Derived Method . . . . . . . . . . . . . . . . . 11 | 3.5.1. Rate-Derived Method . . . . . . . . . . . . . . . . . 12 | |||

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 . . . . . . . . . . 16 | |||

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 . . . . . . . . . . . . . 17 | |||

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. Packet Loss . . . . . . . . . . . . . . . . . . . . . 22 | 3.7.2. Packet Loss . . . . . . . . . . . . . . . . . . . . . 23 | |||

3.7.3. Convergence Packet Loss . . . . . . . . . . . . . . . 22 | 3.7.3. Convergence Packet Loss . . . . . . . . . . . . . . . 23 | |||

3.7.4. Connectivity Packet Loss . . . . . . . . . . . . . . . 23 | 3.7.4. Connectivity Packet Loss . . . . . . . . . . . . . . . 24 | |||

3.7.5. Packet Sampling Interval . . . . . . . . . . . . . . . 23 | 3.7.5. Packet Sampling Interval . . . . . . . . . . . . . . . 25 | |||

3.7.6. Sustained Convergence Validation Time . . . . . . . . 24 | 3.7.6. Sustained Convergence Validation Time . . . . . . . . 25 | |||

3.8. Miscellaneous Terms . . . . . . . . . . . . . . . . . . . 24 | 3.7.7. Forwarding Delay Threshold . . . . . . . . . . . . . . 26 | |||

3.8.1. Stale Forwarding . . . . . . . . . . . . . . . . . . . 24 | 3.8. Miscellaneous Terms . . . . . . . . . . . . . . . . . . . 26 | |||

3.8.2. Nested Convergence Event . . . . . . . . . . . . . . . 25 | 3.8.1. Stale Forwarding . . . . . . . . . . . . . . . . . . . 26 | |||

4. Security Considerations . . . . . . . . . . . . . . . . . . . 25 | 3.8.2. Nested Convergence Event . . . . . . . . . . . . . . . 27 | |||

5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26 | 4. Security Considerations . . . . . . . . . . . . . . . . . . . 27 | |||

6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 26 | 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28 | |||

7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 26 | 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 28 | |||

7.1. Normative References . . . . . . . . . . . . . . . . . . . 26 | 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 28 | |||

7.2. Informative References . . . . . . . . . . . . . . . . . . 27 | 7.1. Normative References . . . . . . . . . . . . . . . . . . . 28 | |||

Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 27 | 7.2. Informative References . . . . . . . . . . . . . . . . . . 29 | |||

Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 29 | ||||

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

This draft describes the terminology for benchmarking Link-State | This draft describes the terminology for benchmarking Link-State | |||

Interior Gateway Protocol (IGP) Convergence. The motivation and | Interior Gateway Protocol (IGP) Convergence. The motivation and | |||

applicability for this benchmarking is provided in [Po09a]. The | applicability for this benchmarking is provided in [Po09a]. The | |||

methodology to be used for this benchmarking is described in [Po09m]. | methodology to be used for this benchmarking is described in [Po09m]. | |||

The purpose of this document is to introduce new terms required to | The purpose of this document is to introduce new terms required to | |||

complete execution of the IGP Route Methodology [Po09m]. | complete execution of the IGP Route Methodology [Po09m]. | |||

skipping to change at page 4, line 31 | skipping to change at page 5, line 31 | |||

This document uses existing terminology defined in other BMWG work. | This document uses existing terminology defined in other BMWG work. | |||

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

Frame Loss Rate [Ref.[Br91], section 3.6] | Frame Loss Rate [Ref.[Br91], section 3.6] | |||

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

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

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

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

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

Out-of-order Packet [Ref.[Po06], section 3.3.2] | Out-of-Order Packet [Ref.[Po06], section 3.3.4] | |||

Duplicate Packet [Ref.[Po06], section 3.3.3] | Duplicate Packet [Ref.[Po06], section 3.3.5] | |||

Packet Reordering [Ref.[Mo06], section 3.3] | Packet Reordering [Ref.[Mo06], section 3.3] | |||

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

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

Jitter [Ref.[Po06], section 3.2.5] | ||||

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

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 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 key words 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. | |||

skipping to change at page 8, line 13 | skipping to change at page 9, line 13 | |||

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 in order to validate the Convergence Recovery Instant. | Time in order to validate the Convergence Recovery Instant. | |||

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

the instant the DUT forwards traffic to all destinations over the | the instant the DUT forwards traffic to all destinations over the | |||

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

When using the Rate-Derived Method, the Convergence Recovery Instant | ||||

falls within the Packet Sampling Interval preceding the first | ||||

interval where the observed Forwarding Rate on the Next-Best Egress | ||||

Interface equals the Offered Load. | ||||

Measurement Units: | Measurement Units: | |||

hh:mm:ss:nnn:uuu, where 'nnn' is milliseconds and 'uuu' is | hh:mm:ss:nnn:uuu, where 'nnn' is milliseconds and 'uuu' is | |||

microseconds. | microseconds. | |||

Issues: None | Issues: None | |||

See Also: | See Also: | |||

Sustained Convergence Validation Time, Full Convergence | Sustained Convergence Validation Time, Full Convergence | |||

skipping to change at page 11, line 35 | skipping to change at page 12, line 26 | |||

Definition: | Definition: | |||

The outbound interface from the DUT for traffic routed to the second- | The outbound interface from the DUT for traffic routed to the second- | |||

best next-hop. | 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 a | |||

Convergence Event. | Convergence Event. | |||

The Next-Best Egress Interface is of the same media type and link | ||||

speed as the Preferred Egress Interface. | ||||

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

Issues: None | Issues: None | |||

See Also: Preferred Egress Interface | See Also: Preferred Egress Interface | |||

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

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

skipping to change at page 12, line 41 | skipping to change at page 13, line 36 | |||

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 all | |||

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

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

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

be used if required. | 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 Offered | |||

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

For maximum accuracy the value for the Packet Sampling Interval | ||||

SHOULD be as small as possible, but the presence of Jitter [Po06] may | ||||

enforce using a larger Packet Sampling Interval. | ||||

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

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

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

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

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

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

in determining if a convergence instant has been reached, Jitter | ||||

SHOULD be observed during each Packet Sampling Interval. The minimum | ||||

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

in presence of Jitter can be calculated with Equation 1. | ||||

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

in presence of Jitter | ||||

= expected number of packets without Jitter | ||||

+/-(max Jitter during Packet Sampling Interval * Offered Load) | ||||

Equation 1 | ||||

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

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

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

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

Forwarding Rate and packet loss. | Forwarding Rate and packet loss. | |||

Rate-Derived Method is a RECOMMENDED method to measure convergence | Rate-Derived Method is a RECOMMENDED method to measure convergence | |||

time benchmarks. | time benchmarks. | |||

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

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

Convergence Event Instant, the Tester SHOULD collect a timestamp of | Convergence Event Instant, the Tester SHOULD collect a timestamp of | |||

skipping to change at page 16, line 4 | skipping to change at page 17, line 22 | |||

Definition: | Definition: | |||

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

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

Derived Method. | 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 1. | 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 1 | Equation 2 | |||

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

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

For the testcases described in [Po09m], it is expected that Full | For the testcases described in [Po09m], it is expected that Full | |||

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

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

Derived Method. | 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 Loss- | |||

skipping to change at page 16, line 44 | skipping to change at page 18, line 14 | |||

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

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

Derived Method. | 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 2. | 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 2 | Equation 3 | |||

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

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

For the testcases described in [Po09m], it is expected that First | For the testcases described in [Po09m], it is expected that First | |||

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

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

Loss-Derived Method. | 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 the | |||

skipping to change at page 17, line 41 | skipping to change at page 19, line 10 | |||

Discussion: | Discussion: | |||

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

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

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

packet loss observed on Preferred Egress Interface and Next-Best | packet loss observed on Preferred Egress Interface and Next-Best | |||

Egress Interface. When benchmarking Route-Specific Convergence Time, | Egress Interface. When benchmarking Route-Specific Convergence Time, | |||

Connectivity Packet Loss is measured and Equation 3 is applied for | Connectivity Packet Loss is measured and Equation 4 is applied for | |||

each measured route. The calculation is equal to Equation 7 in | each measured route. The calculation is equal to Equation 8 in | |||

Section 3.6.5. | 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 3 | Equation 4 | |||

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

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

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

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

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

benchmarking Route-Specific Convergence Time, Convergence Packet Loss | benchmarking Route-Specific Convergence Time, Convergence Packet Loss | |||

is measured and Equation 4 is applied for each measured route. | 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 4 | Equation 5 | |||

The Convergence Event Instant and Traffic Start Instant SHOULD be | The Convergence Event Instant and Traffic Start Instant SHOULD be | |||

collected by the Tester. | collected by the Tester. | |||

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 a | |||

priority value for route entry(ies). Since multiple Route-Specific | priority value for route entry(ies). Since multiple Route-Specific | |||

Convergence Times can be measured it is possible to have an array of | Convergence Times can be measured it is possible to have an array of | |||

skipping to change at page 19, line 6 | skipping to change at page 20, line 22 | |||

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 Packet | |||

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

packet loss observed on Preferred Egress Interface and Next-Best | packet loss observed on Preferred Egress Interface and Next-Best | |||

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

Connectivity Packet Loss is measured and Equation 5 is applied. | Connectivity Packet 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 5 | Equation 6 | |||

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

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

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

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

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

benchmarking Loss-Derived Convergence Time, Convergence Packet Loss | benchmarking Loss-Derived Convergence Time, Convergence Packet Loss | |||

is measured and Equation 6 is applied. | 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 6 | Equation 7 | |||

The Convergence Event Instant and Traffic Start Instant SHOULD be | The Convergence Event Instant and Traffic Start Instant SHOULD be | |||

collected by the Tester. | collected by the Tester. | |||

Measurement Units: seconds | Measurement Units: seconds | |||

Issues: None | Issues: None | |||

See Also: | See Also: | |||

skipping to change at page 20, line 16 | skipping to change at page 21, line 31 | |||

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 Convergence | |||

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

Convergence Event Instant. See discussion in [Po09m]. | Convergence Event Instant. See discussion in [Po09m]. | |||

For the testcases described in [Po09m] the Route Loss of Connectivity | For the testcases described in [Po09m] the Route Loss of Connectivity | |||

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

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

Packet Loss is measured for each route and Equation 7 is applied for | Packet Loss is measured for each route and Equation 8 is applied for | |||

each measured route entry. The calculation is equal to Equation 3 in | each measured route entry. The calculation is equal to Equation 4 in | |||

Section 3.6.3. | 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 7 | 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 | Measurement Units: seconds | |||

Issues: None | Issues: None | |||

See Also: | See Also: | |||

skipping to change at page 21, line 17 | skipping to change at page 22, line 33 | |||

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 in | |||

[Po09m]. | [Po09m]. | |||

For the testcases described in [Po09m] each route's Route Loss of | For the testcases described in [Po09m] each route's 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 Loss-Derived Loss of Connectivity Period, | When benchmarking Loss-Derived Loss of Connectivity Period, | |||

Connectivity Packet Loss is measured for all routes and Equation 8 is | Connectivity Packet Loss is measured for all routes and Equation 9 is | |||

applied. The calculation is equal to Equation 5 in Section 3.6.4. | 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 8 | Equation 9 | |||

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

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

Measurement Units: seconds | Measurement Units: seconds | |||

Issues: None | Issues: None | |||

See Also: | See Also: | |||

skipping to change at page 22, line 45 | skipping to change at page 24, line 12 | |||

The number of packets lost due to a Convergence Event until Full | The number of packets lost due to a Convergence Event until Full | |||

Convergence completes, as observed on the Next-Best Egress Interface. | Convergence completes, as observed on the Next-Best Egress Interface. | |||

Discussion: | Discussion: | |||

Convergence Packet Loss is observed on the Next-Best Egress | Convergence Packet Loss is observed on the Next-Best Egress | |||

Interface. It only needs to be observed for Convergence Events that | Interface. It only needs to be observed for Convergence Events that | |||

do not cause instantaneous traffic loss at Convergence Event Instant. | do not cause instantaneous traffic loss at Convergence Event Instant. | |||

Convergence Packet Loss includes packets that were lost and packets | Convergence Packet Loss includes packets that were lost and packets | |||

that were delayed due to buffering. The magnitude of an acceptable | that were delayed due to buffering. The maximum acceptable | |||

Forwarding Delay is a parameter of the methodology. If a maximum | Forwarding Delay (Forwarding Delay Threshold) is a parameter of the | |||

acceptable Forwarding Delay threshold is applied it MUST be reported. | methodology, if it is applied it MUST be reported. | |||

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

Issues: None | Issues: None | |||

See Also: | See Also: | |||

Packet Loss, Full Convergence, Convergence Event, Connectivity Packet | Packet Loss, Full Convergence, Convergence Event, Connectivity Packet | |||

Loss | Loss | |||

3.7.4. Connectivity Packet Loss | 3.7.4. Connectivity Packet Loss | |||

Definition: | Definition: | |||

The number of packets lost due to a Convergence Event until Full | The number of packets lost due to a Convergence Event until Full | |||

skipping to change at page 23, line 20 | skipping to change at page 24, line 36 | |||

Definition: | Definition: | |||

The number of packets lost due to a Convergence Event until Full | The number of packets lost due to a Convergence Event until Full | |||

Convergence completes. | Convergence completes. | |||

Discussion: | Discussion: | |||

Connectivity Packet Loss is observed on all DUT egress interfaces. | Connectivity Packet Loss is observed on all DUT egress interfaces. | |||

Convergence Packet Loss includes packets that were lost and packets | Connectivity Packet Loss includes packets that were lost and packets | |||

that were delayed due to buffering. The magnitude of an acceptable | that were delayed due to buffering. The maximum acceptable | |||

Forwarding Delay is a parameter of the methodology. If a maximum | Forwarding Delay (Forwarding Delay Threshold) is a parameter of the | |||

acceptable Forwarding Delay threshold is applied it MUST be reported. | methodology, if it is applied it MUST be reported. | |||

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

Issues: None | Issues: None | |||

See Also: | See Also: | |||

Packet Loss, Route Loss of Connectivity Period, Convergence Event, | Packet Loss, Route Loss of Connectivity Period, Convergence Event, | |||

Convergence Packet Loss | Convergence Packet Loss | |||

skipping to change at page 24, line 8 | skipping to change at page 25, line 27 | |||

Forwarding Rate and received packets. | 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 the | |||

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

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

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

time. | time. | |||

The recommended value for configuration of the Packet Sampling | Using a small Packet Sampling Interval in the presence of Jitter | |||

Interval when using the Rate-Derived Method is provided in [Po09m]. | [Po06] may cause fluctuations of the Forwarding Rate observation and | |||

For the other benchmark methods the value of the Packet Sampling | can prevent correct observation of the different convergence time | |||

Interval does not contribute to the measurement accuracy. | instants. | |||

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

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

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

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

larger Packet Sampling Interval. | ||||

Measurement Units: seconds | Measurement Units: seconds | |||

Issues: None | Issues: None | |||

See Also: Rate-Derived Method | See Also: Rate-Derived Method | |||

3.7.6. Sustained Convergence Validation Time | 3.7.6. 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 packet loss. | maintained without additional packet loss. | |||

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 observed. | |||

The RECOMMENDED Sustained Convergence Validation Time to be used is 5 | The RECOMMENDED Sustained Convergence Validation Time to be used is | |||

seconds. The BMWG selected 5 seconds based upon RFC 2544 [Br99] | the time to send 5 consecutive packets to each destination with a | |||

minimum of 5 seconds. The BMWG selected 5 seconds based upon [Br99] | ||||

which recommends waiting 2 seconds for residual frames to arrive | which recommends waiting 2 seconds for residual frames to arrive | |||

(this is the Forwarding Delay threshold for the last packet sent) and | (this is the Forwarding Delay Threshold for the last packet sent) and | |||

5 seconds for DUT restabilization. | 5 seconds for DUT restabilization. | |||

Measurement Units: seconds | Measurement Units: seconds | |||

Issues: None | Issues: None | |||

See Also: | See Also: | |||

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

3.7.7. Forwarding Delay Threshold | ||||

Definition: | ||||

The maximum Forwarding Delay for a packet to be accepted. | ||||

Discussion: | ||||

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

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

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

Threshold is a parameter of the methodology, if it is applied it MUST | ||||

be reported. | ||||

Measurement Units: seconds | ||||

Issues: None | ||||

See Also: | ||||

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

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

3.8.1. Stale Forwarding | 3.8.1. Stale Forwarding | |||

Definition: | Definition: | |||

Forwarding of traffic to route entries that no longer exist or to | Forwarding of traffic to route entries that no longer exist or to | |||

route entries with next-hops that are no longer preferred. | route entries with next-hops that are no longer preferred. | |||

Discussion: | Discussion: | |||

skipping to change at page 26, line 20 | skipping to change at page 28, line 17 | |||

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. IANA Considerations | |||

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

6. Acknowledgements | 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 and the BMWG for their contributions to this work. | Peter De Vriendt, Anuj Dewagan and the BMWG for their contributions | |||

to this work. | ||||

7. References | 7. References | |||

7.1. Normative References | 7.1. 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. | |||

End of changes. 41 change blocks. | ||||

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