draft-ietf-ippm-testplan-rfc2680-03.txt   draft-ietf-ippm-testplan-rfc2680-04.txt 
Network Working Group L. Ciavattone Network Working Group L. Ciavattone
Internet-Draft AT&T Labs Internet-Draft AT&T Labs
Intended status: Informational R. Geib Intended status: Informational R. Geib
Expires: January 9, 2014 Deutsche Telekom Expires: April 21, 2014 Deutsche Telekom
A. Morton A. Morton
AT&T Labs AT&T Labs
M. Wieser M. Wieser
Technical University Darmstadt Technical University Darmstadt
July 8, 2013 October 18, 2013
Test Plan and Results for Advancing RFC 2680 on the Standards Track Test Plan and Results for Advancing RFC 2680 on the Standards Track
draft-ietf-ippm-testplan-rfc2680-03 draft-ietf-ippm-testplan-rfc2680-04
Abstract Abstract
This memo proposes to advance a performance metric RFC along the This memo proposes to advance a performance metric RFC along the
standards track, specifically RFC 2680 on One-way Loss Metrics. standards track, specifically RFC 2680 on One-way Loss Metrics.
Observing that the metric definitions themselves should be the Observing that the metric definitions themselves should be the
primary focus rather than the implementations of metrics, this memo primary focus rather than the implementations of metrics, this memo
describes the test procedures to evaluate specific metric requirement describes the test procedures to evaluate specific metric requirement
clauses to determine if the requirement has been interpreted and clauses to determine if the requirement has been interpreted and
implemented as intended. Two completely independent implementations implemented as intended. Two completely independent implementations
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 9, 2014. This Internet-Draft will expire on April 21, 2014.
Copyright Notice Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the Copyright (c) 2013 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
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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 . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. RFC 2680 Coverage . . . . . . . . . . . . . . . . . . . . 5 1.1. RFC 2680 Coverage . . . . . . . . . . . . . . . . . . . . 5
2. A Definition-centric metric advancement process . . . . . . . 5 2. A Definition-centric metric advancement process . . . . . . . 5
3. Test configuration . . . . . . . . . . . . . . . . . . . . . . 6 3. Test configuration . . . . . . . . . . . . . . . . . . . . . . 5
4. Error Calibration, RFC 2680 . . . . . . . . . . . . . . . . . 10 4. Error Calibration, RFC 2680 . . . . . . . . . . . . . . . . . 9
4.1. Clock Synchronization Calibration . . . . . . . . . . . . 10 4.1. Clock Synchronization Calibration . . . . . . . . . . . . 9
4.2. Packet Loss Determination Error . . . . . . . . . . . . . 10 4.2. Packet Loss Determination Error . . . . . . . . . . . . . 10
5. Pre-determined Limits on Equivalence . . . . . . . . . . . . . 11 5. Pre-determined Limits on Equivalence . . . . . . . . . . . . . 10
6. Tests to evaluate RFC 2680 Specifications . . . . . . . . . . 12 6. Tests to evaluate RFC 2680 Specifications . . . . . . . . . . 11
6.1. One-way Loss, ADK Sample Comparison . . . . . . . . . . . 12 6.1. One-way Loss, ADK Sample Comparison . . . . . . . . . . . 11
6.1.1. 340B/Periodic Cross-imp. results . . . . . . . . . . . 13 6.1.1. 340B/Periodic Cross-imp. results . . . . . . . . . . . 12
6.1.2. 64B/Periodic Cross-imp. results . . . . . . . . . . . 14 6.1.2. 64B/Periodic Cross-imp. results . . . . . . . . . . . 13
6.1.3. 64B/Poisson Cross-imp. results . . . . . . . . . . . . 15 6.1.3. 64B/Poisson Cross-imp. results . . . . . . . . . . . . 14
6.1.4. Conclusions on the ADK Results for One-way Packet 6.1.4. Conclusions on the ADK Results for One-way Packet
Loss . . . . . . . . . . . . . . . . . . . . . . . . . 16 Loss . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.2. One-way Loss, Delay threshold . . . . . . . . . . . . . . 16 6.2. One-way Loss, Delay threshold . . . . . . . . . . . . . . 15
6.2.1. NetProbe results for Loss Threshold . . . . . . . . . 17 6.2.1. NetProbe results for Loss Threshold . . . . . . . . . 16
6.2.2. Perfas Results for Loss Threshold . . . . . . . . . . 18 6.2.2. Perfas Results for Loss Threshold . . . . . . . . . . 17
6.2.3. Conclusions for Loss Threshold . . . . . . . . . . . . 18 6.2.3. Conclusions for Loss Threshold . . . . . . . . . . . . 17
6.3. One-way Loss with Out-of-Order Arrival . . . . . . . . . . 18 6.3. One-way Loss with Out-of-Order Arrival . . . . . . . . . . 17
6.4. Poisson Sending Process Evaluation . . . . . . . . . . . . 19 6.4. Poisson Sending Process Evaluation . . . . . . . . . . . . 18
6.4.1. NetProbe Results . . . . . . . . . . . . . . . . . . . 20 6.4.1. NetProbe Results . . . . . . . . . . . . . . . . . . . 19
6.4.2. Perfas+ Results . . . . . . . . . . . . . . . . . . . 21 6.4.2. Perfas+ Results . . . . . . . . . . . . . . . . . . . 20
6.4.3. Conclusions for Goodness-of-Fit . . . . . . . . . . . 23 6.4.3. Conclusions for Goodness-of-Fit . . . . . . . . . . . 22
6.5. Implementation of Statistics for One-way Loss . . . . . . 23 6.5. Implementation of Statistics for One-way Loss . . . . . . 22
7. Conclusions for RFC 2680bis . . . . . . . . . . . . . . . . . 23 7. Conclusions for RFC 2680bis . . . . . . . . . . . . . . . . . 23
8. Security Considerations . . . . . . . . . . . . . . . . . . . 24 8. Security Considerations . . . . . . . . . . . . . . . . . . . 23
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 24 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 23
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 25 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 24
11.1. Normative References . . . . . . . . . . . . . . . . . . . 25 11.1. Normative References . . . . . . . . . . . . . . . . . . . 24
11.2. Informative References . . . . . . . . . . . . . . . . . . 26 11.2. Informative References . . . . . . . . . . . . . . . . . . 25
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 27 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 26
1. Introduction 1. Introduction
The IETF (IP Performance Metrics working group, IPPM) has considered The IETF (IP Performance Metrics working group, IPPM) has considered
how to advance their metrics along the standards track since 2001. how to advance their metrics along the standards track since 2001.
A renewed work effort sought to investigate ways in which the The renewed work effort sought to investigate ways in which the
measurement variability could be reduced and thereby simplify the measurement variability could be reduced and thereby simplify the
problem of comparison for equivalence. problem of comparison for equivalence. As a result, there is
consensus (captured in [RFC6576]) that equivalent results from
There is consensus [RFC6576] that the metric definitions should be independent implementations of metric specifications are sufficient
the primary focus of evaluation rather than the implementations of evidence that the specifications themselves are clear and
metrics, and equivalent results are deemed to be evidence that the unambiguous; it is the parallel concept of protocol interoperability
metric specifications are clear and unambiguous. This is the metric for metric specifications. The advancement process either produces
specification equivalent of protocol interoperability. The confidence that the metric definitions and supporting material are
advancement process either produces confidence that the metric clearly worded and unambiguous, OR, identifies ways in which the
definitions and supporting material are clearly worded and metric definitions should be revised to achieve clarity. It is a
unambiguous, OR, identifies ways in which the metric definitions non-goal to compare the specific implementations themselves.
should be revised to achieve clarity.
The process should also permit identification of options that were The process also permits identification of options described in the
not implemented, so that they can be removed from the advancing metric RFC that were not implemented, so that they can be removed
specification (this is an aspect more typical of protocol advancement from the advancing specification (this is an aspect more typical of
along the standards track). protocol advancement along the standards track).
This memo's purpose is to implement the current approach for This memo's purpose is to implement the current approach for
[RFC2680]. [RFC2680] and document the results.
In particular, this memo documents consensus on the extent of In particular, this memo documents consensus on the extent of
tolerable errors when assessing equivalence in the results. In tolerable errors when assessing equivalence in the results. In
discussions, the IPPM working group agreed that test plan and discussions, the IPPM working group agreed that test plan and
procedures should include the threshold for determining equivalence, procedures should include the threshold for determining equivalence,
and this information should be available in advance of cross- and this information should be available in advance of cross-
implementation comparisons. This memo includes procedures for same- implementation comparisons. This memo includes procedures for same-
implementation comparisons to help set the equivalence threshold. implementation comparisons to help set the equivalence threshold.
Another aspect of the metric RFC advancement process is the Another aspect of the metric RFC advancement process is the
requirement to document the work and results. The procedures of requirement to document the work and results. The procedures of
[RFC2026] are expanded in[RFC5657], including sample implementation [RFC2026] are expanded in[RFC5657], including sample implementation
and interoperability reports. This memo follows the template in and interoperability reports. This memo follows the template in
[I-D.morton-ippm-advance-metrics] for the report that accompanies the [RFC6808] for the report that accompanies the protocol action request
protocol action request submitted to the Area Director, including submitted to the Area Director, including description of the test
description of the test set-up, procedures, results for each set-up, procedures, results for each implementation, and conclusions.
implementation and conclusions.
Although the conclusion reached through testing is that [RFC2680] The conclusion reached is that [RFC2680] should be advanced on the
should be advanced on the Standards Track with modifications, the Standards Track with modifications. The revised text of RFC 2680bis
revised text of RFC 2680bis is not yet ready for review. Therefore, is ready for review [I-D.morton-ippm-2680-bis], but awaits work-in
this memo documents the information to support [RFC2680] advancement, progress to update the IPPM Framework [RFC2330]. Therefore, this
and the approval of RFC2680bis is left for future action. memo documents the information to support [RFC2680] advancement, and
the approval of RFC2680bis is left for future action.
1.1. RFC 2680 Coverage 1.1. RFC 2680 Coverage
This plan is intended to cover all critical requirements and sections This plan is intended to cover all critical requirements and sections
of [RFC2680]. of [RFC2680].
Note that there are only five instances of the requirement term Note that there are only five instances of the requirement term
"MUST" in [RFC2680] outside of the boilerplate and [RFC2119] "MUST" in [RFC2680] outside of the boilerplate and [RFC2119]
reference. reference.
Material may be added as it is "discovered" (apparently, not all Material may be added as it is "discovered" (apparently, not all
requirements use requirements language). requirements use requirements language).
2. A Definition-centric metric advancement process 2. A Definition-centric metric advancement process
The process described in Section 3.5 of [RFC6576] takes as a first The process described in Section 3.5 of [RFC6576] takes as a first
principle that the metric definitions, embodied in the text of the principle that the metric definitions, embodied in the text of the
RFCs, are the objects that require evaluation and possible revision RFCs, are the objects that require evaluation and possible revision
in order to advance to the next step on the standards track. in order to advance to the next step on the standards track. This
memo follows that process.
IF two implementations do not measure an equivalent singleton or
sample, or produce the an equivalent statistic,
AND sources of measurement error do not adequately explain the lack
of agreement,
THEN the details of each implementation should be audited along with
the exact definition text, to determine if there is a lack of clarity
that has caused the implementations to vary in a way that affects the
correspondence of the results.
IF there was a lack of clarity or multiple legitimate interpretations
of the definition text,
THEN the text should be modified and the resulting memo proposed for
consensus and advancement along the standards track.
Finally, all the findings MUST be documented in a report that can
support advancement on the standards track, similar to those
described in [RFC5657]. The list of measurement devices used in
testing satisfies the implementation requirement, while the test
results provide information on the quality of each specification in
the metric RFC (the surrogate for feature interoperability).
3. Test configuration 3. Test configuration
One metric implementation used was NetProbe version 5.8.5, (an One metric implementation used was NetProbe version 5.8.5 (an earlier
earlier version is used in the WIPM system and deployed world-wide version is used in the WIPM system and deployed world-wide [WIPM]).
[WIPM]). NetProbe uses UDP packets of variable size, and can produce NetProbe uses UDP packets of variable size, and can produce test
test streams with Periodic [RFC3432] or Poisson [RFC2330] sample streams with Periodic [RFC3432] or Poisson [RFC2330] sample
distributions. distributions.
The other metric implementation used was Perfas+ version 3.1, The other metric implementation used was Perfas+ version 3.1,
developed by Deutsche Telekom [Perfas]. Perfas+ uses UDP unicast developed by Deutsche Telekom [Perfas]. Perfas+ uses UDP unicast
packets of variable size (but supports also TCP and multicast). Test packets of variable size (but also supports TCP and multicast). Test
streams with periodic, Poisson or uniform sample distributions may be streams with periodic, Poisson, or uniform sample distributions may
used. be used.
Figure 1 shows a view of the test path as each Implementation's test Figure 1 shows a view of the test path as each Implementation's test
flows pass through the Internet and the L2TPv3 tunnel IDs (1 and 2), flows pass through the Internet and the L2TPv3 tunnel IDs (1 and 2),
based on Figure 1 of [RFC6576]. based on Figure 1 of [RFC6576].
+----+ +----+ +----+ +----+ +------------+ +------------+
|Imp1| |Imp1| ,---. |Imp2| |Imp2| | Imp 1 | ,---. | Imp 2 |
+----+ +----+ / \ +-------+ +----+ +----+ +------------+ / \ +-------+ +------------+
| V100 | V200 / \ | Tunnel| | V300 | V400 | V100 ^ V200 / \ | Tunnel| | V300 ^ V400
| | ( ) | Head | | | | | ( ) | Head | | |
+--------+ +------+ | |__| Router| +----------+ +--------+ +------+ | |__| Router| +----------+
|Ethernet| |Tunnel| |Internet | +---B---+ |Ethernet | |Ethernet| |Tunnel| |Internet | +---B---+ |Ethernet |
|Switch |--|Head |-| | | |Switch | |Switch |--|Head |-| | | |Switch |
+-+--+---+ |Router| | | +---+---+--+--+--+----+ +-+--+---+ |Router| | | +---+---+--+--+--+----+
|__| +--A---+ ( ) |Network| |__| |__| +--A---+ ( ) |Network| |__|
\ / |Emulat.| \ / |Emulat.|
U-turn \ / |"netem"| U-turn U-turn \ / |"netem"| U-turn
V300 to V400 `-+-' +-------+ V100 to V200 V300 to V400 `-+-' +-------+ V100 to V200
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*-------<-----+ F1 | | | | | | *-------<-----+ F1 | | | | | |
+---------+ | | +~~~~~~~~~| |~~~~| | | | +---------+ | | +~~~~~~~~~| |~~~~| | | |
| transmit|-* *-| | | |<-* | | | transmit|-* *-| | | |<-* | |
| Imp 2 | | Tunnel ( ) | | | | Imp 2 | | Tunnel ( ) | | |
| receive |-<-F2-| ID 2 \ / |<----* | | receive |-<-F2-| ID 2 \ / |<----* |
+---------+ +~~~~~~~~~~~\ /~~~~~~| Switch | +---------+ +~~~~~~~~~~~\ /~~~~~~| Switch |
`-+-' +--------+ `-+-' +--------+
Illustrations of a test setup with a bi-directional tunnel. The Illustrations of a test setup with a bi-directional tunnel. The
upper diagram emphasizes the VLAN connectivity and geographical upper diagram emphasizes the VLAN connectivity and geographical
location. The lower diagram shows example flows traveling between location (where "Imp #" is the sender and receiver of implementation
two measurement implementations (for simplicity, only two flows are 1 or 2, either Perfas+ and NetProbe in this test). The lower diagram
shown). shows example flows traveling between two measurement
implementations. For simplicity only two flows are shown, and netem
is omitted (it would appear before or after the Internet, depending
on the flow).
Figure 1 Figure 1
The testing employs the Layer 2 Tunnel Protocol, version 3 (L2TPv3) The testing employs the Layer 2 Tunnel Protocol, version 3 (L2TPv3)
[RFC3931] tunnel between test sites on the Internet. The tunnel IP [RFC3931] tunnel between test sites on the Internet. The tunnel IP
and L2TPv3 headers are intended to conceal the test equipment and L2TPv3 headers are intended to conceal the test equipment
addresses and ports from hash functions that would tend to spread addresses and ports from hash functions that would tend to spread
different test streams across parallel network resources, with likely different test streams across parallel network resources, with likely
variation in performance as a result. variation in performance as a result.
At each end of the tunnel, one pair of VLANs encapsulated in the At each end of the tunnel, one pair of VLANs encapsulated in the
tunnel are looped-back so that test traffic is returned to each test tunnel are looped-back so that test traffic is returned to each test
site. Thus, test streams traverse the L2TP tunnel twice, but appear site. Thus, test streams traverse the L2TP tunnel twice, but appear
to be one-way tests from the test equipment point of view. to be one-way tests from the test equipment point of view.
The network emulator is a host running Fedora 14 Linux The network emulator is a host running Fedora 14 Linux [Fedora] with
[http://fedoraproject.org/] with IP forwarding enabled and the IP forwarding enabled and the "netem" Network emulator as part of the
"netem" Network emulator as part of the Fedora Kernel 2.6.35.11 [http Fedora Kernel 2.6.35.11 [netem] loaded and operating. The standard
://www.linuxfoundation.org/collaborate/workgroups/networking/netem] kernel is "tickless" replacing the previous periodic timer (250HZ,
loaded and operating. Connectivity across the netem/Fedora host was with 4ms uncertainty) interrupts with on-demand interrupts.
accomplished by bridging Ethernet VLAN interfaces together with Connectivity across the netem/Fedora host was accomplished by
"brctl" commands (e.g., eth1.100 <-> eth2.100). The netem emulator bridging Ethernet VLAN interfaces together with "brctl" commands
was activated on one interface (eth1) and only operates on test (e.g., eth1.100 <-> eth2.100). The netem emulator was activated on
streams traveling in one direction. In some tests, independent netem one interface (eth1) and only operates on test streams traveling in
instances operated separately on each VLAN. one direction. In some tests, independent netem instances operated
separately on each VLAN.
The links between the netem emulator host and router and switch were The links between the netem emulator host and router and switch were
found to be 100baseTx-HD (100Mbps half duplex) as reported by "mii- found to be 100baseTx-HD (100Mbps half duplex) as reported by "mii-
tool"when the testing was complete. Use of Half Duplex was not tool" [mii-tool], when testing was complete. Use of half duplex was
intended, but probably added a small amount of delay variation that not intended, but probably added a small amount of delay variation
could have been avoided in full duplex mode. that could have been avoided in full duplex mode.
Each individual test was run with common packet rates (1 pps, 10pps) Each individual test was run with common packet rates (1 pps, 10pps)
Poisson/Periodic distributions, and IP packet sizes of 64, 340, and Poisson/Periodic distributions, and IP packet sizes of 64, 340, and
500 Bytes. 500 Bytes.
For these tests, a stream of at least 300 packets were sent from For these tests, a stream of at least 300 packets was sent from
Source to Destination in each implementation. Periodic streams (as source to destination in each implementation. Periodic streams (as
per [RFC3432]) with 1 second spacing were used, except as noted. per [RFC3432]) with 1 second spacing were used, except as noted.
As required in Section 2.8.1 of [RFC2680], packet Type-P must be As required in Section 2.8.1 of [RFC2680], packet Type-P must be
reported. The packet Type-P for this test was IP-UDP with Best reported. The packet Type-P for this test was IP-UDP with Best
Effort DCSP. These headers were encapsulated according to the L2TPv3 Effort DSCP. These headers were encapsulated according to the L2TPv3
specifications [RFC3931], and thus may not influence the treatment specifications [RFC3931], and thus may not influence the treatment
received as the packets traversed the Internet. received as the packets traversed the Internet.
With the L2TPv3 tunnel in use, the metric name for the testing With the L2TPv3 tunnel in use, the metric name for the testing
configured here (with respect to the IP header exposed to Internet configured here (with respect to the IP header exposed to Internet
processing) is: processing) is:
Type-IP-protocol-115-One-way-Packet-Loss-<StreamType>-Stream Type-IP-protocol-115-One-way-Packet-Loss-<StreamType>-Stream
With (Section 3.2. [RFC2680]) Metric Parameters: With (Section 3.2. [RFC2680]) metric parameters:
+ Src, the IP address of a host (12.3.167.16 or 193.159.144.8) + Src, the IP address of a host (12.3.167.16 or 193.159.144.8)
+ Dst, the IP address of a host (193.159.144.8 or 12.3.167.16) + Dst, the IP address of a host (193.159.144.8 or 12.3.167.16)
+ T0, a time + T0, a time
+ Tf, a time + Tf, a time
+ lambda, a rate in reciprocal seconds + lambda, a rate in reciprocal seconds
+ Thresh, a maximum waiting time in seconds (see Section 2.8.2 of + Thresh, a maximum waiting time in seconds (see Section 2.8.2 of
[RFC2680]) and (Section 3.8. [RFC2680]) [RFC2680]) and (Section 3.8. [RFC2680])
Metric Units: A sequence of pairs; the elements of each pair are: Metric Units: A sequence of pairs; the elements of each pair are:
+ T, a time, and + T, a time, and
skipping to change at page 9, line 17 skipping to change at page 8, line 21
+ Thresh, a maximum waiting time in seconds (see Section 2.8.2 of + Thresh, a maximum waiting time in seconds (see Section 2.8.2 of
[RFC2680]) and (Section 3.8. [RFC2680]) [RFC2680]) and (Section 3.8. [RFC2680])
Metric Units: A sequence of pairs; the elements of each pair are: Metric Units: A sequence of pairs; the elements of each pair are:
+ T, a time, and + T, a time, and
+ L, either a zero or a one + L, either a zero or a one
The values of T in the sequence are monotonic increasing. Note that The values of T in the sequence are monotonically increasing. Note
T would be a valid parameter to the *singleton* Type-P-One-way- that T would be a valid parameter of *singleton* Type-P-One-way-
Packet-Loss, and that L would be a valid value of Type-P-One-way- Packet-Loss, and that L would be a valid value of Type-P-One-way-
Packet Loss (see Section 2 of [RFC2680]). Packet Loss (see Section 2 of [RFC2680]).
Also, Section 2.8.4 of [RFC2680] recommends that the path SHOULD be Also, Section 2.8.4 of [RFC2680] recommends that the path SHOULD be
reported. In this test set-up, most of the path details will be reported. In this test set-up, most of the path details will be
concealed from the implementations by the L2TPv3 tunnels, thus a more concealed from the implementations by the L2TPv3 tunnels, thus a more
informative path trace route can be conducted by the routers at each informative path trace route can be conducted by the routers at each
location. location.
When NetProbe is used in production, a traceroute is conducted in When NetProbe is used in production, a traceroute is conducted in
skipping to change at page 10, line 27 skipping to change at page 9, line 27
n54ny02jt.ip.att.net (12.122.80.237) [AS 7018] 4 msec n54ny02jt.ip.att.net (12.122.80.237) [AS 7018] 4 msec
5 192.205.34.182 [AS 7018] 0 msec 5 192.205.34.182 [AS 7018] 0 msec
192.205.34.150 [AS 7018] 0 msec 192.205.34.150 [AS 7018] 0 msec
192.205.34.182 [AS 7018] 4 msec 192.205.34.182 [AS 7018] 4 msec
6 da-rg12-i.DA.DE.NET.DTAG.DE (62.154.1.30) [AS 3320] 88 msec 88 msec 6 da-rg12-i.DA.DE.NET.DTAG.DE (62.154.1.30) [AS 3320] 88 msec 88 msec
88 msec 88 msec
7 217.89.29.62 [AS 3320] 88 msec 88 msec 88 msec 7 217.89.29.62 [AS 3320] 88 msec 88 msec 88 msec
8 217.89.29.55 [AS 3320] 88 msec 88 msec 88 msec 8 217.89.29.55 [AS 3320] 88 msec 88 msec 88 msec
9 * * * 9 * * *
NetProbe Traceroute
It was only possible to conduct the traceroute for the measured path It was only possible to conduct the traceroute for the measured path
on one of the tunnel-head routers (the normal trace facilities of the on one of the tunnel-head routers (the normal trace facilities of the
measurement systems are confounded by the L2TPv3 tunnel measurement systems are confounded by the L2TPv3 tunnel
encapsulation). encapsulation).
4. Error Calibration, RFC 2680 4. Error Calibration, RFC 2680
An implementation is required to report calibration results on clock An implementation is required to report calibration results on clock
synchronization in Section 2.8.3 of [RFC2680] (also required in synchronization in Section 2.8.3 of [RFC2680] (also required in
Section 3.7 of [RFC2680] for sample metrics). Section 3.7 of [RFC2680] for sample metrics).
skipping to change at page 11, line 15 skipping to change at page 10, line 20
discarded in error. discarded in error.
In previous test efforts [I-D.morton-ippm-advance-metrics], NetProbe In previous test efforts [I-D.morton-ippm-advance-metrics], NetProbe
produced 6 multicast streams with an aggregate bit rate over 53 produced 6 multicast streams with an aggregate bit rate over 53
Mbit/s, in order to characterize the 1-way capacity of a NISTNet- Mbit/s, in order to characterize the 1-way capacity of a NISTNet-
based emulator. Neither the emulator nor the pair of NetProbe based emulator. Neither the emulator nor the pair of NetProbe
implementations used in this testing dropped any packets in these implementations used in this testing dropped any packets in these
streams. streams.
The maximum load used here between any 2 NetProbe implementations was The maximum load used here between any 2 NetProbe implementations was
be 11.5 Mbit/s divided equally among 3 unicast test streams. We 11.5 Mbit/s divided equally among 3 unicast test streams. We
conclude that steady resource usage does not contribute error concluded that steady resource usage does not contribute error
(additional loss) to the measurements. (additional loss) to the measurements.
5. Pre-determined Limits on Equivalence 5. Pre-determined Limits on Equivalence
In this section, we provide the numerical limits on comparisons In this section, we provide the numerical limits on comparisons
between implementations, in order to declare that the results are between implementations in order to declare that the results are
equivalent and therefore, the tested specification is clear. equivalent and therefore, the tested specification is clear.
A key point is that the allowable errors, corrections, and confidence A key point is that the allowable errors, corrections, and confidence
levels only need to be sufficient to detect mis-interpretation of the levels only need to be sufficient to detect misinterpretation of the
tested specification resulting in diverging implementations. tested specification resulting in diverging implementations.
Also, the allowable error must be sufficient to compensate for Also, the allowable error must be sufficient to compensate for
measured path differences. It was simply not possible to measure measured path differences. It was simply not possible to measure
fully identical paths in the VLAN-loopback test configuration used, fully identical paths in the VLAN-loopback test configuration used,
and this practical compromise must be taken into account. and this practical compromise must be taken into account.
For Anderson-Darling K-sample (ADK) [ADK] comparisons, the required For Anderson-Darling K-sample (ADK) [ADK] comparisons, the required
confidence factor for the cross-implementation comparisons SHALL be confidence factor for the cross-implementation comparisons SHALL be
the smallest of: the smallest of:
skipping to change at page 12, line 47 skipping to change at page 11, line 49
measurement devices to operate tests in their designated pair of measurement devices to operate tests in their designated pair of
VLANs. VLANs.
2. Measure a sample of one-way packet loss singletons with 2 or more 2. Measure a sample of one-way packet loss singletons with 2 or more
implementations, using identical options and network emulator implementations, using identical options and network emulator
settings (if used). settings (if used).
3. Measure a sample of one-way packet loss singletons with *four or 3. Measure a sample of one-way packet loss singletons with *four or
more* instances of the *same* implementations, using identical more* instances of the *same* implementations, using identical
options, noting that connectivity differences SHOULD be the same options, noting that connectivity differences SHOULD be the same
as for the cross implementation testing. as for cross implementation testing.
4. If less than ten test streams are available, skip to step 7. 4. If less than ten test streams are available, skip to step 7.
5. Apply the ADK comparison procedures (see Appendix C of [RFC6576]) 5. Apply the ADK comparison procedures (see Appendix C of [RFC6576])
and determine the resolution and confidence factor for and determine the resolution and confidence factor for
distribution equivalence of each same-implementation comparison distribution equivalence of each same-implementation comparison
and each cross-implementation comparison. and each cross-implementation comparison.
6. Take the coarsest resolution and confidence factor for 6. Take the coarsest resolution and confidence factor for
distribution equivalence from the same-implementation pairs, or distribution equivalence from the same-implementation pairs, or
the limit defined in Section 5 above, as a limit on the the limit defined in Section 5 above, as a limit on the
equivalence threshold for these experimental conditions. equivalence threshold for these experimental conditions.
7. Compare the cross-implementation ADK performance with the 7. Compare the cross-implementation ADK performance with the
equivalence threshold determined in step 5 to determine if equivalence threshold determined in step 5 to determine if
equivalence can be declared. equivalence can be declared.
The common parameters used for tests in this section are: The metric parameters varied for each loss test, and they are listed
first in each sub-section below.
The cross-implementation comparison uses a simple ADK analysis The cross-implementation comparison uses a simple ADK analysis
[Rtool] [Radk], where all NetProbe loss counts are compared with all [Rtool] [Radk], where all NetProbe loss counts are compared with all
Perfas+ loss results. Perfas+ loss results.
In the result analysis of this section: In the result analysis of this section:
o All comparisons used 1 packet resolution. o All comparisons used 1 packet resolution.
o No Correction Factors were applied. o No Correction Factors were applied.
skipping to change at page 14, line 5 skipping to change at page 13, line 5
o Periodic sampling at 1 packet per second o Periodic sampling at 1 packet per second
o Test duration = 1200 seconds (during April 7, 2011, EDT) o Test duration = 1200 seconds (during April 7, 2011, EDT)
The netem emulator was set for 100ms constant delay, with 10% loss The netem emulator was set for 100ms constant delay, with 10% loss
ratio. In this experiment, the netem emulator was configured to ratio. In this experiment, the netem emulator was configured to
operate independently on each VLAN and thus the emulator itself is a operate independently on each VLAN and thus the emulator itself is a
potential source of error when comparing streams that traverse the potential source of error when comparing streams that traverse the
test path in different directions. test path in different directions.
=======================================
A07bps_loss <- c(114, 175, 138, 142, 181, 105) (NetProbe) A07bps_loss <- c(114, 175, 138, 142, 181, 105) (NetProbe)
A07per_loss <- c(115, 128, 136, 127, 139, 138) (Perfas+) A07per_loss <- c(115, 128, 136, 127, 139, 138) (Perfas+)
> A07bps_loss <- c(114, 175, 138, 142, 181, 105) > A07bps_loss <- c(114, 175, 138, 142, 181, 105)
> A07per_loss <- c(115, 128, 136, 127, 139, 138) > A07per_loss <- c(115, 128, 136, 127, 139, 138)
> >
> A07cross_loss_ADK <- adk.test(A07bps_loss, A07per_loss) > A07cross_loss_ADK <- adk.test(A07bps_loss, A07per_loss)
> A07cross_loss_ADK > A07cross_loss_ADK
Anderson-Darling k-sample test. Anderson-Darling k-sample test.
skipping to change at page 14, line 31 skipping to change at page 13, line 32
Standard deviation of Anderson Darling Criterion: 0.6569 Standard deviation of Anderson Darling Criterion: 0.6569
T = (Anderson Darling Criterion - mean)/sigma T = (Anderson Darling Criterion - mean)/sigma
Null Hypothesis: All samples come from a common population. Null Hypothesis: All samples come from a common population.
t.obs P-value extrapolation t.obs P-value extrapolation
not adj. for ties 0.52043 0.20604 0 not adj. for ties 0.52043 0.20604 0
adj. for ties 0.62679 0.18607 0 adj. for ties 0.62679 0.18607 0
=======================================
The cross-implementation comparisons pass the ADK criterion. The cross-implementation comparisons pass the ADK criterion.
6.1.2. 64B/Periodic Cross-imp. results 6.1.2. 64B/Periodic Cross-imp. results
Tests described in this section used: Tests described in this section used:
o IP header + payload = 64 octets o IP header + payload = 64 octets
o Periodic sampling at 1 packet per second o Periodic sampling at 1 packet per second
o Test duration = 300 seconds (during March 24, 2011, EDT) o Test duration = 300 seconds (during March 24, 2011, EDT)
The netem emulator was set for 0ms constant delay, with 10% loss The netem emulator was set for 0ms constant delay, with 10% loss
ratio. ratio.
=======================================
> M24per_loss <- c(42,34,35,35) (Perfas+) > M24per_loss <- c(42,34,35,35) (Perfas+)
> M24apd_23BC_loss <- c(27,39,29,24) (NetProbe) > M24apd_23BC_loss <- c(27,39,29,24) (NetProbe)
> M24apd_loss23BC_ADK <- adk.test(M24apd_23BC_loss,M24per_loss) > M24apd_loss23BC_ADK <- adk.test(M24apd_23BC_loss,M24per_loss)
> M24apd_loss23BC_ADK > M24apd_loss23BC_ADK
Anderson-Darling k-sample test. Anderson-Darling k-sample test.
Number of samples: 2 Number of samples: 2
Sample sizes: 4 4 Sample sizes: 4 4
Total number of values: 8 Total number of values: 8
Number of unique values: 7 Number of unique values: 7
skipping to change at page 15, line 30 skipping to change at page 14, line 32
Null Hypothesis: All samples come from a common population. Null Hypothesis: All samples come from a common population.
t.obs P-value extrapolation t.obs P-value extrapolation
not adj. for ties 0.76921 0.16200 0 not adj. for ties 0.76921 0.16200 0
adj. for ties 0.90935 0.14113 0 adj. for ties 0.90935 0.14113 0
Warning: At least one sample size is less than 5. Warning: At least one sample size is less than 5.
p-values may not be very accurate. p-values may not be very accurate.
=======================================
The cross-implementation comparisons pass the ADK criterion. The cross-implementation comparisons pass the ADK criterion.
6.1.3. 64B/Poisson Cross-imp. results 6.1.3. 64B/Poisson Cross-imp. results
Tests described in this section used: Tests described in this section used:
o IP header + payload = 64 octets o IP header + payload = 64 octets
o Poisson sampling at lambda = 1 packet per second o Poisson sampling at lambda = 1 packet per second
o Test duration = 20 minutes (during April 27, 2011, EDT) o Test duration = 20 minutes (during April 27, 2011, EDT)
The netem configuration was 0ms delay and 10% loss, but there were The netem configuration was 0ms delay and 10% loss, but there were
two passes through an emulator for each stream, and loss emulation two passes through an emulator for each stream, and loss emulation
was present for 18 minutes of the 20 minute test . was present for 18 minutes of the 20 minute test.
=======================================
A27aps_loss <- c(91,110,113,102,111,109,112,113) (NetProbe) A27aps_loss <- c(91,110,113,102,111,109,112,113) (NetProbe)
A27per_loss <- c(95,123,126,114) (Perfas+) A27per_loss <- c(95,123,126,114) (Perfas+)
A27cross_loss_ADK <- adk.test(A27aps_loss, A27per_loss) A27cross_loss_ADK <- adk.test(A27aps_loss, A27per_loss)
> A27cross_loss_ADK > A27cross_loss_ADK
Anderson-Darling k-sample test. Anderson-Darling k-sample test.
Number of samples: 2 Number of samples: 2
Sample sizes: 8 4 Sample sizes: 8 4
skipping to change at page 16, line 33 skipping to change at page 15, line 34
Null Hypothesis: All samples come from a common population. Null Hypothesis: All samples come from a common population.
t.obs P-value extrapolation t.obs P-value extrapolation
not adj. for ties 2.15099 0.04145 0 not adj. for ties 2.15099 0.04145 0
adj. for ties 1.93129 0.05125 0 adj. for ties 1.93129 0.05125 0
Warning: At least one sample size is less than 5. Warning: At least one sample size is less than 5.
p-values may not be very accurate. p-values may not be very accurate.
> >
=======================================
The cross-implementation comparisons barely pass the ADK criterion at The cross-implementation comparisons barely pass the ADK criterion at
95% = 1.960 when adjusting for ties. 95% = 1.960 when adjusting for ties.
6.1.4. Conclusions on the ADK Results for One-way Packet Loss 6.1.4. Conclusions on the ADK Results for One-way Packet Loss
We conclude that the two implementations are capable of producing We conclude that the two implementations are capable of producing
equivalent one-way packet loss measurements based on their equivalent one-way packet loss measurements based on their
interpretation of [RFC2680] . interpretation of [RFC2680].
6.2. One-way Loss, Delay threshold 6.2. One-way Loss, Delay threshold
This test determines if implementations use the same configured This test determines if implementations use the same configured
maximum waiting time delay from one measurement to another under maximum waiting time delay from one measurement to another under
different delay conditions, and correctly declare packets arriving in different delay conditions, and correctly declare packets arriving in
excess of the waiting time threshold as lost. excess of the waiting time threshold as lost.
See Section 2.8.2 of [RFC2680]. See Section 2.8.2 of [RFC2680].
1. configure an L2TPv3 path between test sites, and each pair of 1. Configure an L2TPv3 path between test sites, and each pair of
measurement devices to operate tests in their designated pair of measurement devices to operate tests in their designated pair of
VLANs. VLANs.
2. configure the network emulator to add 1.0 sec one-way constant 2. Configure the network emulator to add 1sec one-way constant delay
delay in one direction of transmission. in one direction of transmission.
3. measure (average) one-way delay with 2 or more implementations, 3. Measure (average) one-way delay with 2 or more implementations,
using identical waiting time thresholds (Thresh) for loss set at using identical waiting time thresholds (Thresh) for loss set at
3 seconds. 3 seconds.
4. configure the network emulator to add 3 sec one-way constant 4. Configure the network emulator to add 3 sec one-way constant
delay in one direction of transmission equivalent to 2 seconds of delay in one direction of transmission equivalent to 2 seconds of
additional one-way delay (or change the path delay while test is additional one-way delay (or change the path delay while test is
in progress, when there are sufficient packets at the first delay in progress, when there are sufficient packets at the first delay
setting) setting).
5. repeat/continue measurements 5. Repeat/continue measurements.
6. observe that the increase measured in step 5 caused all packets 6. Observe that the increase measured in step 5 caused all packets
with 2 sec additional delay to be declared lost, and that all with 2 sec additional delay to be declared lost, and that all
packets that arrive successfully in step 3 are assigned a valid packets that arrive successfully in step 3 are assigned a valid
one-way delay. one-way delay.
The common parameters used for tests in this section are: The common parameters used for tests in this section are:
o IP header + payload = 64 octets o IP header + payload = 64 octets
o Poisson sampling at lambda = 1 packet per second o Poisson sampling at lambda = 1 packet per second
o Test duration = 900 seconds total (March 21) o Test duration = 900 seconds total (March 21, 2011 EDT)
The netem emulator was set to add constant delays as specified in the The netem emulator settings added constant delays as specified in the
procedure above. procedure above.
6.2.1. NetProbe results for Loss Threshold 6.2.1. NetProbe results for Loss Threshold
In NetProbe, the Loss Threshold is implemented uniformly over all In NetProbe, the Loss Threshold was implemented uniformly over all
packets as a post-processing routine. With the Loss Threshold set at packets as a post-processing routine. With the Loss Threshold set at
3 seconds, all packets with one-way delay >3 seconds are marked 3 seconds, all packets with one-way delay >3 seconds were marked
"Lost" and included in the Lost Packet list with their transmission "Lost" and included in the Lost Packet list with their transmission
time (as required in Section 3.3 of [RFC2680]). This resulted in 342 time (as required in Section 3.3 of [RFC2680]). This resulted in 342
packets designated as lost in one of the test streams (with average packets designated as lost in one of the test streams (with average
delay = 3.091 sec). delay = 3.091 sec).
6.2.2. Perfas Results for Loss Threshold 6.2.2. Perfas Results for Loss Threshold
Perfas+ uses a fixed Loss Threshold which was not adjustable during Perfas+ uses a fixed Loss Threshold which was not adjustable during
this study. The Loss Threshold is approximately one minute, and this study. The Loss Threshold is approximately one minute, and
emulation of a delay of this size was not attempted. However, it is emulation of a delay of this size was not attempted. However, it is
skipping to change at page 18, line 36 skipping to change at page 17, line 36
Section 3.6 of [RFC2680] indicates that implementations need to Section 3.6 of [RFC2680] indicates that implementations need to
ensure that reordered packets are handled correctly using an ensure that reordered packets are handled correctly using an
uncapitalized "must". In essence, this is an implied requirement uncapitalized "must". In essence, this is an implied requirement
because the correct packet must be identified as lost if it fails to because the correct packet must be identified as lost if it fails to
arrive before its delay threshold under all circumstances, and arrive before its delay threshold under all circumstances, and
reordering is always a possibility on IP network paths. See reordering is always a possibility on IP network paths. See
[RFC4737] for the definition of reordering used in IETF standard- [RFC4737] for the definition of reordering used in IETF standard-
compliant measurements. compliant measurements.
Using the procedure of section 6.1, the netem emulator was set to Using the procedure of section 6.1, the netem emulator was set to
introduce significant delay (2000 ms) and delay variation (1000 ms), introduce 10% loss, significant delay (2000 ms) and delay variation
which was sufficient to produce packet reordering because each (1000 ms), which was sufficient to produce packet reordering because
packet's emulated delay is independent from others, and 10% loss. each packet's emulated delay is independent from others.
The tests described in this section used: The tests described in this section used:
o IP header + payload = 64 octets o IP header + payload = 64 octets
o Periodic sampling = 1 packet per second o Periodic sampling = 1 packet per second
o Test duration = 600 seconds (during May 2, 2011, EDT) o Test duration = 600 seconds (during May 2, 2011, EDT)
=======================================
> Y02aps_loss <- c(53,45,67,55) (NetProbe) > Y02aps_loss <- c(53,45,67,55) (NetProbe)
> Y02per_loss <- c(59,62,67,69) (Perfas+) > Y02per_loss <- c(59,62,67,69) (Perfas+)
> Y02cross_loss_ADK <- adk.test(Y02aps_loss, Y02per_loss) > Y02cross_loss_ADK <- adk.test(Y02aps_loss, Y02per_loss)
> Y02cross_loss_ADK > Y02cross_loss_ADK
Anderson-Darling k-sample test. Anderson-Darling k-sample test.
Number of samples: 2 Number of samples: 2
Sample sizes: 4 4 Sample sizes: 4 4
Total number of values: 8 Total number of values: 8
Number of unique values: 7 Number of unique values: 7
skipping to change at page 19, line 30 skipping to change at page 18, line 31
Null Hypothesis: All samples come from a common population. Null Hypothesis: All samples come from a common population.
t.obs P-value extrapolation t.obs P-value extrapolation
not adj. for ties 1.11282 0.11531 0 not adj. for ties 1.11282 0.11531 0
adj. for ties 1.19571 0.10616 0 adj. for ties 1.19571 0.10616 0
Warning: At least one sample size is less than 5. Warning: At least one sample size is less than 5.
p-values may not be very accurate. p-values may not be very accurate.
> >
=======================================
The test results indicate that extensive reordering was present. The test results indicate that extensive reordering was present.
Both implementations capture the extensive delay variation between Both implementations capture the extensive delay variation between
adjacent packets. In NetProbe, packet arrival order is preserved in adjacent packets. In NetProbe, packet arrival order is preserved in
the raw measurement files, so an examination of arrival packet the raw measurement files, so an examination of arrival packet
sequence numbers also indicates reordering. sequence numbers also indicates reordering.
Despite extensive continuous packet reordering present in the Despite extensive continuous packet reordering present in the
transmission path, the distributions of loss counts from the two transmission path, the distributions of loss counts from the two
implementations pass the ADK criterion at 95% = 1.960. implementations pass the ADK criterion at 95% = 1.960.
skipping to change at page 20, line 13 skipping to change at page 19, line 17
the base functionality of the R-tool for Statistical Analysis[Rtool], the base functionality of the R-tool for Statistical Analysis[Rtool],
and performed using the Anderson-Darling Goodness-of-Fit test package and performed using the Anderson-Darling Goodness-of-Fit test package
(ADGofTest) [Radgof]. The Goodness-of-Fit criterion derived from (ADGofTest) [Radgof]. The Goodness-of-Fit criterion derived from
[RFC2330] requires a test statistic value AD <= 2.492 for 5% [RFC2330] requires a test statistic value AD <= 2.492 for 5%
significance. The Appendix of [RFC2330] also notes that there may be significance. The Appendix of [RFC2330] also notes that there may be
difficulty satisfying the ADGofTest when the sample includes many difficulty satisfying the ADGofTest when the sample includes many
packets (when 8192 were used, the test always failed, but smaller packets (when 8192 were used, the test always failed, but smaller
sets of the stream passed). sets of the stream passed).
Both implementations were configured to produce Poisson distributions Both implementations were configured to produce Poisson distributions
with lambda = 1 packet per second. with lambda = 1 packet per second, and assign received packet
timestamps in the measurement application (above UDP layer, see the
calibration results in Section 4 of [RFC6808] for assessment of
error).
6.4.1. NetProbe Results 6.4.1. NetProbe Results
Section 11.4 of [RFC2330] suggests three possible measurement points Section 11.4 of [RFC2330] suggests three possible measurement points
to evaluate the Poisson distribution. The NetProbe analysis uses to evaluate the Poisson distribution. The NetProbe analysis uses
"user-level timestamps made just before or after the system call for "user-level timestamps made just before or after the system call for
transmitting the packet". transmitting the packet".
The statistical summary for two NetProbe streams is below: The statistical summary for two NetProbe streams is below:
=======================================
> summary(a27ms$s1[2:1152]) > summary(a27ms$s1[2:1152])
Min. 1st Qu. Median Mean 3rd Qu. Max. Min. 1st Qu. Median Mean 3rd Qu. Max.
0.0100 0.2900 0.6600 0.9846 1.3800 8.6390 0.0100 0.2900 0.6600 0.9846 1.3800 8.6390
> summary(a27ms$s2[2:1152]) > summary(a27ms$s2[2:1152])
Min. 1st Qu. Median Mean 3rd Qu. Max. Min. 1st Qu. Median Mean 3rd Qu. Max.
0.010 0.280 0.670 0.979 1.365 8.829 0.010 0.280 0.670 0.979 1.365 8.829
=======================================
We see that both the Means are near the specified lambda = 1. We see that both the Means are near the specified lambda = 1.
The results of ADGoF tests for these two streams is shown below: The results of ADGoF tests for these two streams is shown below:
=======================================
> ad.test( a27ms$s1[2:101], pexp, 1) > ad.test( a27ms$s1[2:101], pexp, 1)
Anderson-Darling GoF Test Anderson-Darling GoF Test
data: a27ms$s1[2:101] and pexp data: a27ms$s1[2:101] and pexp
AD = 0.8908, p-value = 0.4197 AD = 0.8908, p-value = 0.4197
alternative hypothesis: NA alternative hypothesis: NA
> ad.test( a27ms$s1[2:1001], pexp, 1) > ad.test( a27ms$s1[2:1001], pexp, 1)
skipping to change at page 21, line 36 skipping to change at page 20, line 37
AD = 0.3597, p-value = 0.8873 AD = 0.3597, p-value = 0.8873
alternative hypothesis: NA alternative hypothesis: NA
> ad.test( a27ms$s2[2:1001], pexp, 1) > ad.test( a27ms$s2[2:1001], pexp, 1)
Anderson-Darling GoF Test Anderson-Darling GoF Test
data: a27ms$s2[2:1001] and pexp data: a27ms$s2[2:1001] and pexp
AD = 0.6913, p-value = 0.5661 AD = 0.6913, p-value = 0.5661
alternative hypothesis: NA alternative hypothesis: NA
=======================================
We see that both 100 and 1000 packet sets from two different streams We see that both 100 and 1000 packet sets from two different streams
(s1 and s2) all passed the AD <= 2.492 criterion. (s1 and s2) all passed the AD <= 2.492 criterion.
6.4.2. Perfas+ Results 6.4.2. Perfas+ Results
Section 11.4 of [RFC2330] suggests three possible measurement points Section 11.4 of [RFC2330] suggests three possible measurement points
to evaluate the Poisson distribution. The Perfas+ analysis uses to evaluate the Poisson distribution. The Perfas+ analysis uses
"wire times for the packets as recorded using a packet filter". "wire times for the packets as recorded using a packet filter".
However, due to limited access at the Perfas+ side of the test setup, However, due to limited access at the Perfas+ side of the test setup,
the captures were made after the Perfas+ streams traversed the the captures were made after the Perfas+ streams traversed the
production network, adding a small amount of unwanted delay variation production network, adding a small amount of unwanted delay variation
to the wire times (and possibly error due to packet loss). to the wire times (and possibly error due to packet loss).
The statistical summary for two Perfas+ streams is below: The statistical summary for two Perfas+ streams is below:
=======================================
> summary(a27pe$p1) > summary(a27pe$p1)
Min. 1st Qu. Median Mean 3rd Qu. Max. Min. 1st Qu. Median Mean 3rd Qu. Max.
0.004 0.347 0.788 1.054 1.548 4.231 0.004 0.347 0.788 1.054 1.548 4.231
> summary(a27pe$p2) > summary(a27pe$p2)
Min. 1st Qu. Median Mean 3rd Qu. Max. Min. 1st Qu. Median Mean 3rd Qu. Max.
0.0010 0.2710 0.7080 0.9696 1.3740 7.1160 0.0010 0.2710 0.7080 0.9696 1.3740 7.1160
We see that both the Means are near the specified lambda = 1. =======================================
We see that both the means are near the specified lambda = 1.
The results of ADGoF tests for these two streams is shown below: The results of ADGoF tests for these two streams is shown below:
=======================================
> ad.test(a27pe$p1, pexp, 1 ) > ad.test(a27pe$p1, pexp, 1 )
Anderson-Darling GoF Test Anderson-Darling GoF Test
data: a27pe$p1 and pexp data: a27pe$p1 and pexp
AD = 1.1364, p-value = 0.2930 AD = 1.1364, p-value = 0.2930
alternative hypothesis: NA alternative hypothesis: NA
> ad.test(a27pe$p2, pexp, 1 ) > ad.test(a27pe$p2, pexp, 1 )
skipping to change at page 23, line 17 skipping to change at page 22, line 20
> ad.test(a27pe$p2[101:193], pexp, 1 ) > ad.test(a27pe$p2[101:193], pexp, 1 )
Anderson-Darling GoF Test Anderson-Darling GoF Test
data: a27pe$p2[101:193] and pexp data: a27pe$p2[101:193] and pexp
AD = 0.3381, p-value = 0.9068 AD = 0.3381, p-value = 0.9068
alternative hypothesis: NA alternative hypothesis: NA
> >
=======================================
We see that both 193, 100, and 93 packet sets from two different We see that both 193, 100, and 93 packet sets from two different
streams (p1 and p2) all passed the AD <= 2.492 criterion. streams (p1 and p2) all passed the AD <= 2.492 criterion.
6.4.3. Conclusions for Goodness-of-Fit 6.4.3. Conclusions for Goodness-of-Fit
Both NetProbe and Perfas+ implementations produce adequate Poisson Both NetProbe and Perfas+ implementations produce adequate Poisson
distributions when according to the Anderson-Darling Goodness-of-Fit distributions according to the Anderson-Darling Goodness-of-Fit at
at the 5% significance (1-alpha = 0.05, or 95% confidence level). the 5% significance (1-alpha = 0.05, or 95% confidence level).
6.5. Implementation of Statistics for One-way Loss 6.5. Implementation of Statistics for One-way Loss
We check which statistics were implemented, and report on those We check which statistics were implemented, and report on those
facts, noting that Section 4 of [RFC2680] does not specify the facts, noting that Section 4 of [RFC2680] does not specify the
calculations exactly, and gives only some illustrative examples. calculations exactly, and gives only some illustrative examples.
NetProbe Perfas NetProbe Perfas
4.1. Type-P-One-way-Packet-Loss-Average yes yes 4.1. Type-P-One-way-Packet-Loss-Average yes yes
skipping to change at page 24, line 6 skipping to change at page 23, line 12
and this is an area for likely revision of the text to make it more and this is an area for likely revision of the text to make it more
consistent with wide-spread usage. consistent with wide-spread usage.
7. Conclusions for RFC 2680bis 7. Conclusions for RFC 2680bis
This memo concludes that [RFC2680] should be advanced on the This memo concludes that [RFC2680] should be advanced on the
standards track, and recommends the following edits to improve the standards track, and recommends the following edits to improve the
text (which are not deemed significant enough to affect maturity). text (which are not deemed significant enough to affect maturity).
o Revise Type-P-One-way-Packet-Loss-Ave to Type-P-One-way-Delay- o Revise Type-P-One-way-Packet-Loss-Ave to Type-P-One-way-Delay-
Packet-Loss-Ratio Packet-Loss-Ratio .
o Regarding implementation of the loss delay threshold (section o Regarding implementation of the loss delay threshold (section
6.2), the assumption of post-processing is compliant, and the text 6.2), the assumption of post-processing is compliant, and the text
of RFC 2680bis should be revised slightly to include this point. of RFC 2680bis should be revised slightly to include this point.
o The IETF has reached consensus on guidance for reporting metrics o The IETF has reached consensus on guidance for reporting metrics
in [RFC6703], and this memo should be referenced in RFC2680bis to in [RFC6703], and this memo should be referenced in RFC2680bis to
incorporate recent experience where appropriate. incorporate recent experience where appropriate.
We note that there are at least two Errata on [RFC2680] and these We note that there are at least two Errata on [RFC2680] and these
skipping to change at page 25, line 6 skipping to change at page 24, line 12
The authors thank Lars Eggert for his continued encouragement to The authors thank Lars Eggert for his continued encouragement to
advance the IPPM metrics during his tenure as AD Advisor. advance the IPPM metrics during his tenure as AD Advisor.
Nicole Kowalski supplied the needed CPE router for the NetProbe side Nicole Kowalski supplied the needed CPE router for the NetProbe side
of the test set-up, and graciously managed her testing in spite of of the test set-up, and graciously managed her testing in spite of
issues caused by dual-use of the router. Thanks Nicole! issues caused by dual-use of the router. Thanks Nicole!
The "NetProbe Team" also acknowledges many useful discussions on The "NetProbe Team" also acknowledges many useful discussions on
statistical interpretation with Ganga Maguluri. statistical interpretation with Ganga Maguluri.
Constructive comments and helpful reviews where also provided by Bill
Cerveny, Joachim Fabini, and Ann Cerveny.
11. References 11. References
11.1. Normative References 11.1. Normative References
[RFC2026] Bradner, S., "The Internet Standards Process -- Revision [RFC2026] Bradner, S., "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, October 1996. 3", BCP 9, RFC 2026, October 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, [RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis,
"Framework for IP Performance Metrics", RFC 2330, "Framework for IP Performance Metrics", RFC 2330,
May 1998. May 1998.
[RFC2679] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
Delay Metric for IPPM", RFC 2679, September 1999.
[RFC2680] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way [RFC2680] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
Packet Loss Metric for IPPM", RFC 2680, September 1999. Packet Loss Metric for IPPM", RFC 2680, September 1999.
[RFC3432] Raisanen, V., Grotefeld, G., and A. Morton, "Network [RFC3432] Raisanen, V., Grotefeld, G., and A. Morton, "Network
performance measurement with periodic streams", RFC 3432, performance measurement with periodic streams", RFC 3432,
November 2002. November 2002.
[RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M. [RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M.
Zekauskas, "A One-way Active Measurement Protocol Zekauskas, "A One-way Active Measurement Protocol
(OWAMP)", RFC 4656, September 2006. (OWAMP)", RFC 4656, September 2006.
[RFC4737] Morton, A., Ciavattone, L., Ramachandran, G., Shalunov, [RFC4737] Morton, A., Ciavattone, L., Ramachandran, G., Shalunov,
S., and J. Perser, "Packet Reordering Metrics", RFC 4737, S., and J. Perser, "Packet Reordering Metrics", RFC 4737,
November 2006. November 2006.
[RFC4814] Newman, D. and T. Player, "Hash and Stuffing: Overlooked
Factors in Network Device Benchmarking", RFC 4814,
March 2007.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J. [RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)", Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
RFC 5357, October 2008. RFC 5357, October 2008.
[RFC5657] Dusseault, L. and R. Sparks, "Guidance on Interoperation [RFC5657] Dusseault, L. and R. Sparks, "Guidance on Interoperation
and Implementation Reports for Advancement to Draft and Implementation Reports for Advancement to Draft
Standard", BCP 9, RFC 5657, September 2009. Standard", BCP 9, RFC 5657, September 2009.
[RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New [RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New
Performance Metric Development", BCP 170, RFC 6390, Performance Metric Development", BCP 170, RFC 6390,
skipping to change at page 26, line 26 skipping to change at page 25, line 24
IP Network Performance Metrics: Different Points of View", IP Network Performance Metrics: Different Points of View",
RFC 6703, August 2012. RFC 6703, August 2012.
[RFC6808] Ciavattone, L., Geib, R., Morton, A., and M. Wieser, "Test [RFC6808] Ciavattone, L., Geib, R., Morton, A., and M. Wieser, "Test
Plan and Results Supporting Advancement of RFC 2679 on the Plan and Results Supporting Advancement of RFC 2679 on the
Standards Track", RFC 6808, December 2012. Standards Track", RFC 6808, December 2012.
11.2. Informative References 11.2. Informative References
[ADK] Scholz, F. and M. Stephens, "K-sample Anderson-Darling [ADK] Scholz, F. and M. Stephens, "K-sample Anderson-Darling
Tests of fit, for continuous and discrete cases", Tests of Fit, for Continuous and Discrete cases",
University of Washington, Technical Report No. 81, University of Washington, Technical Report No. 81,
May 1986. May 1986.
[Fedora] "http://fedoraproject.org/".
[I-D.morton-ippm-2680-bis]
Almes, G., Zekauskas, M., and A. Morton, "A One-Way Loss
Metric for IPPM", draft-morton-ippm-2680-bis-01 (work in
progress), August 2013.
[I-D.morton-ippm-advance-metrics] [I-D.morton-ippm-advance-metrics]
Morton, A., "Lab Test Results for Advancing Metrics on the Morton, A., "Lab Test Results for Advancing Metrics on the
Standards Track", draft-morton-ippm-advance-metrics-02 Standards Track", draft-morton-ippm-advance-metrics-02
(work in progress), October 2010. (work in progress), October 2010.
[Perfas] Heidemann, C., "Qualitaet in IP-Netzen Messverfahren", [Perfas] Heidemann, C., "Qualitaet in IP-Netzen Messverfahren",
published by ITG Fachgruppe, 2nd meeting 5.2.3 (NGN) http: published by ITG Fachgruppe, 2nd meeting 5.2.3 (NGN) http:
//www.itg523.de/oeffentlich/01nov/ //www.itg523.de/oeffentlich/01nov/
Heidemann_QOS_Messverfahren.pdf , November 2001. Heidemann_QOS_Messverfahren.pdf , November 2001.
skipping to change at page 27, line 11 skipping to change at page 26, line 15
2008. 2008.
[Rtool] R Development Core Team, "R: A language and environment [Rtool] R Development Core Team, "R: A language and environment
for statistical computing. R Foundation for Statistical for statistical computing. R Foundation for Statistical
Computing, Vienna, Austria. ISBN 3-900051-07-0, URL Computing, Vienna, Austria. ISBN 3-900051-07-0, URL
http://www.R-project.org/", , 2011. http://www.R-project.org/", , 2011.
[WIPM] "AT&T Global IP Network", [WIPM] "AT&T Global IP Network",
http://ipnetwork.bgtmo.ip.att.net/pws/index.html, 2012. http://ipnetwork.bgtmo.ip.att.net/pws/index.html, 2012.
[mii-tool]
"http://man7.org/linux/man-pages/man8/mii-tool.8.html".
[netem] "http://www.linuxfoundation.org/collaborate/workgroups/
networking/netem".
Authors' Addresses Authors' Addresses
Len Ciavattone Len Ciavattone
AT&T Labs AT&T Labs
200 Laurel Avenue South 200 Laurel Avenue South
Middletown, NJ 07748 Middletown, NJ 07748
USA USA
Phone: +1 732 420 1239 Phone: +1 732 420 1239
Fax: Fax:
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