draft-morton-ippm-2679-bis-05.txt		draft-morton-ippm-2679-bis-06.txt
	Network Working Group G. Almes		Network Working Group G. Almes
	Internet-Draft Texas A&M		Internet-Draft Texas A&M
	Obsoletes: 2679 (if approved) S. Kalidindi		Obsoletes: 2679 (if approved) S. Kalidindi
	Intended status: Standards Track Ixia		Intended status: Standards Track Ixia
	Expires: January 5, 2015 M. Zekauskas		Expires: April 9, 2015 M. Zekauskas
	Internet2		Internet2
	A. Morton, Ed.		A. Morton, Ed.
	AT&T Labs		AT&T Labs
	July 4, 2014		October 6, 2014
	A One-Way Delay Metric for IPPM		A One-Way Delay Metric for IPPM
	draft-morton-ippm-2679-bis-05		draft-morton-ippm-2679-bis-06
	Abstract		Abstract
	This memo (RFC 2679 bis) defines a metric for one-way delay of		This memo (RFC 2679 bis) defines a metric for one-way delay of
	packets across Internet paths. It builds on notions introduced and		packets across Internet paths. It builds on notions introduced and
	discussed in the IPPM Framework document, RFC 2330; the reader is		discussed in the IPPM Framework document, RFC 2330; the reader is
	assumed to be familiar with that document.		assumed to be familiar with that document.
	Requirements Language		Requirements Language
	skipping to change at page 1, line 44		skipping to change at page 1, line 44
	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 5, 2015.		This Internet-Draft will expire on April 9, 2015.
	Copyright Notice		Copyright Notice
	Copyright (c) 2014 IETF Trust and the persons identified as the		Copyright (c) 2014 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
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	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
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	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. RFC 2679 bis . . . . . . . . . . . . . . . . . . . . . . . . 3		1. RFC 2679 bis . . . . . . . . . . . . . . . . . . . . . . . . 3
	2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4		2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5
	2.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . 5		2.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . 6
	2.2. General Issues Regarding Time . . . . . . . . . . . . . . 6		2.2. General Issues Regarding Time . . . . . . . . . . . . . . 7
	3. A Singleton Definition for One-way Delay . . . . . . . . . . 7		3. A Singleton Definition for One-way Delay . . . . . . . . . . 8
	3.1. Metric Name: . . . . . . . . . . . . . . . . . . . . . . 7		3.1. Metric Name: . . . . . . . . . . . . . . . . . . . . . . 8
	3.2. Metric Parameters: . . . . . . . . . . . . . . . . . . . 7		3.2. Metric Parameters: . . . . . . . . . . . . . . . . . . . 8
	3.3. Metric Units: . . . . . . . . . . . . . . . . . . . . . . 7		3.3. Metric Units: . . . . . . . . . . . . . . . . . . . . . . 8
	3.4. Definition: . . . . . . . . . . . . . . . . . . . . . . . 7		3.4. Definition: . . . . . . . . . . . . . . . . . . . . . . . 8
	3.5. Discussion: . . . . . . . . . . . . . . . . . . . . . . . 8		3.5. Discussion: . . . . . . . . . . . . . . . . . . . . . . . 9
	3.6. Methodologies: . . . . . . . . . . . . . . . . . . . . . 9		3.6. Methodologies: . . . . . . . . . . . . . . . . . . . . . 10
	3.7. Errors and Uncertainties: . . . . . . . . . . . . . . . . 10		3.7. Errors and Uncertainties: . . . . . . . . . . . . . . . . 11
	3.7.1. Errors or uncertainties related to Clocks . . . . . . 10		3.7.1. Errors or uncertainties related to Clocks . . . . . . 11
	3.7.2. Errors or uncertainties related to Wire-time vs Host-		3.7.2. Errors or uncertainties related to Wire-time vs Host-
	time . . . . . . . . . . . . . . . . . . . . . . . . 11		time . . . . . . . . . . . . . . . . . . . . . . . . 12
	3.7.3. Calibration . . . . . . . . . . . . . . . . . . . . . 12		3.7.3. Calibration . . . . . . . . . . . . . . . . . . . . . 13
	3.8. Reporting the metric: . . . . . . . . . . . . . . . . . . 14		3.8. Reporting the metric: . . . . . . . . . . . . . . . . . . 15
	3.8.1. Type-P . . . . . . . . . . . . . . . . . . . . . . . 14		3.8.1. Type-P . . . . . . . . . . . . . . . . . . . . . . . 15
	3.8.2. Loss Threshold . . . . . . . . . . . . . . . . . . . 14		3.8.2. Loss Threshold . . . . . . . . . . . . . . . . . . . 16
	3.8.3. Calibration Results . . . . . . . . . . . . . . . . . 15		3.8.3. Calibration Results . . . . . . . . . . . . . . . . . 16
	3.8.4. Path . . . . . . . . . . . . . . . . . . . . . . . . 15		3.8.4. Path . . . . . . . . . . . . . . . . . . . . . . . . 16
	4. A Definition for Samples of One-way Delay . . . . . . . . . . 15		4. A Definition for Samples of One-way Delay . . . . . . . . . . 16
	4.1. Metric Name: . . . . . . . . . . . . . . . . . . . . . . 16		4.1. Metric Name: . . . . . . . . . . . . . . . . . . . . . . 17
	4.2. Metric Parameters: . . . . . . . . . . . . . . . . . . . 16		4.2. Metric Parameters: . . . . . . . . . . . . . . . . . . . 17
	4.3. Metric Units: . . . . . . . . . . . . . . . . . . . . . . 16		4.3. Metric Units: . . . . . . . . . . . . . . . . . . . . . . 17
	4.4. Definition: . . . . . . . . . . . . . . . . . . . . . . . 16		4.4. Definition: . . . . . . . . . . . . . . . . . . . . . . . 17
	4.5. Discussion: . . . . . . . . . . . . . . . . . . . . . . . 17		4.5. Discussion: . . . . . . . . . . . . . . . . . . . . . . . 18
	4.6. Methodologies: . . . . . . . . . . . . . . . . . . . . . 17		4.6. Methodologies: . . . . . . . . . . . . . . . . . . . . . 18
	4.7. Errors and Uncertainties: . . . . . . . . . . . . . . . . 18		4.7. Errors and Uncertainties: . . . . . . . . . . . . . . . . 19
	4.8. Reporting the metric: . . . . . . . . . . . . . . . . . . 18		4.8. Reporting the metric: . . . . . . . . . . . . . . . . . . 19
	5. Some Statistics Definitions for One-way Delay . . . . . . . . 18		5. Some Statistics Definitions for One-way Delay . . . . . . . . 19
	5.1. Type-P-One-way-Delay-Percentile . . . . . . . . . . . . . 18		5.1. Type-P-One-way-Delay-Percentile . . . . . . . . . . . . . 19
	5.2. Type-P-One-way-Delay-Median . . . . . . . . . . . . . . . 19		5.2. Type-P-One-way-Delay-Median . . . . . . . . . . . . . . . 20
	5.3. Type-P-One-way-Delay-Minimum . . . . . . . . . . . . . . 19		5.3. Type-P-One-way-Delay-Minimum . . . . . . . . . . . . . . 21
	5.4. Type-P-One-way-Delay-Inverse-Percentile . . . . . . . . . 20		5.4. Type-P-One-way-Delay-Inverse-Percentile . . . . . . . . . 21
	6. Security Considerations . . . . . . . . . . . . . . . . . . . 20		6. Security Considerations . . . . . . . . . . . . . . . . . . . 21
	7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21		7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
	8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21		8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22
	9. Refetrences (temporary) . . . . . . . . . . . . . . . . . . . 21		9. References . . . . . . . . . . . . . . . . . . . . . . . . . 22
	10. References . . . . . . . . . . . . . . . . . . . . . . . . . 21		9.1. Normative References . . . . . . . . . . . . . . . . . . 22
	10.1. Normative References . . . . . . . . . . . . . . . . . . 21		9.2. Informative References . . . . . . . . . . . . . . . . . 23
	10.2. Informative References . . . . . . . . . . . . . . . . . 22		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23
	1. RFC 2679 bis		1. RFC 2679 bis
	The following text constitutes RFC 2769 bis proposed for advancement		The following text constitutes RFC 2769 bis proposed for advancement
	on the IETF Standards Track.		on the IETF Standards Track. This section tracks the changes from
			[RFC2679].
	[I-D.ietf-ippm-testplan-rfc2679] (now approved) provides the test		[RFC6808] provides the test plan and results supporting [RFC2679]
	plan and results supporting [RFC2679] advancement along the standards		advancement along the standards track, according to the process in
	track, according to the process in [RFC6576]. The conclusions of		[RFC6576]. The conclusions of [RFC6808] list four minor
	[I-D.ietf-ippm-testplan-rfc2679] list four minor modifications for		modifications:
	inclusion:
	1. Section 6.2.3 of [I-D.ietf-ippm-testplan-rfc2679] asserts that		1. Section 6.2.3 of [RFC6808] asserts that the assumption of post-
	the assumption of post-processing to enforce a constant waiting		processing to enforce a constant waiting time threshold is
	time threshold is compliant, and that the text of the RFC should		compliant, and that the text of the RFC should be revised
	be revised slightly to include this point (see the last list item		slightly to include this point (see the last list item of section
	of section 3.6, below).		3.6, below).
	2. Section 6.5 of [I-D.ietf-ippm-testplan-rfc2679] indicates that		2. Section 6.5 of [RFC6808] indicates that Type-P-One-way-Delay-
	Type-P-One-way-Delay-Inverse-Percentile statistic has been		Inverse-Percentile statistic has been ignored in both
	ignored in both implementations, so it is a candidate for removal		implementations, so it is a candidate for removal or deprecation
	or deprecation in RFC2679bis (this small discrepancy does not		in RFC2679bis (this small discrepancy does not affect candidacy
	affect candidacy for advancement) (see section 5.4, below).		for advancement) (see section 5.4, below).
	3. The IETF has reached consensus on guidance for reporting metrics		3. The IETF has reached consensus on guidance for reporting metrics
	in [RFC6703], and this memo should be referenced in RFC2679bis to		in [RFC6703], and this memo should be referenced in RFC2679bis to
	incorporate recent experience where appropriate (see the last		incorporate recent experience where appropriate (see the last
	list item of section 3.6, section 3.8, and section 5 below).		list item of section 3.6, section 3.8, and section 5 below).
	4. There is currently one erratum with status "Held for document		4. There is currently one erratum with status "Held for document
	update" for [RFC2679], and it appears this minor revision and		update" for [RFC2679], and it appears this minor revision and
	additional text should be incorporated in RFC2679bis (see section		additional text should be incorporated in RFC2679bis (see section
	5.1).		5.1).
	A small number of updates to the [RFC2679] text have been proposed		A number of updates to the [RFC2679] text have been implemented in
	(by the current Editor) in the text below, principally to reference		the text below, to reference key IPPM RFCs that were approved after
	key IPPM RFCs that were approved after [RFC2679].
	Section 5.4.4 of RFC 6390 suggests a common template for performance		[RFC2679], and to address comments on the IPPM mailing list
			describing current conditions and experience.
			1. Near the end of section 2.1, update of a network example using
			ATM and clarification of TCP's affect on queue occupation and
			importance of one-way delay measurement.
			2. Explicit inclusion of the maximum waiting time input parameter
			in section 3.2 and 4.2, reflecting recognition of this parameter
			in more recent RFCs and ITU-T Recommendation Y.1540.
			3. Addition of reference to RFC6703 in the discussion of packet
			life time and application timeouts in section 3.5.
			4. Addition of reference to the default requirement (that packets
			be standard-formed) from RFC2330 as a new list item in section
			3.5.
			5. GPS-based NTP experience replaces "to be tested" in section 3.5.
			6. Added parenthetical guidance on minimizing interval between
			timestamp placement to send time in section 3.6.
			7. Added text recognizing the impending deployment of transport
			layer encryption in section 3.6.
			8. Section 3.7.2 notes that some current systems perform host time
			stamping on the network interface hardware.
			9. "instrument" replaced by the defined term "host" in sections
			3.7.3 and 3.8.3.
			10. Added reference to RFC 3432 Periodic sampling alongside Poisson
			sampling in section 4, and also noting that a truncated Poisson
			distribution may be needed with modern networks as described in
			the IPPM Framework update, RFC7312.
			11. Add reference to RFC 4737 Reordering metric in the related
			discussion of section 4.6, Methodologies.
			12. Clarifying the conclusions on two related points on harm to
			measurements (recognition of measurement traffic for unexpected
			priority treatment and attacker traffic which emulates
			measurement) in section 6, Security Considerations.
			Section 5.4.4 of [RFC6390] suggests a common template for performance
	metrics partially derived from previous IPPM and BMWG RFCs, but also		metrics partially derived from previous IPPM and BMWG RFCs, but also
	some new items. All of the RFC 6390 Normative points are covered,		contains some new items. All of the [RFC6390] Normative points are
	but not quite in the same section names or orientation. Several of		covered, but not quite in the same section names or orientation.
	the Informative points are covered. It is proposed to "grandfather-		Several of the Informative points are covered. Maintaining the
	in" bis RFCs w.r.t. RFC 6390 (keeping the familiar outline and		familiar outline of IPPM literature has both value and minimizes
	minimizing unnecessary differences), and focus efforts on applying		unnecessary differences between this revised RFC and current/future
	the template with new metric memos instead.		IPPM RFCs.
	The publication of RFC 6921 suggests an area where this memo might be		The publication of RFC 6921 suggested an area where this memo might
	updated. Packet transfer on Faster-Than-Light (FTL) networks could		need updating. Packet transfer on Faster-Than-Light (FTL) networks
	result in negative delays and packet reordering, and both are covered		could result in negative delays and packet reordering, however both
	as possibilities in the current text (we note that this is an April		are covered as possibilities in the current text and no revisions are
	1st RFC).		deemed necessary (we also note that this is an April 1st RFC).
	2. Introduction		2. Introduction
	This memo defines a metric for one-way delay of packets across		This memo defines a metric for one-way delay of packets across
	Internet paths. It builds on notions introduced and discussed in the		Internet paths. It builds on notions introduced and discussed in the
	IPPM Framework document, RFC 2330 [1]; the reader is assumed to be		IPPM Framework document, [RFC2330]; the reader is assumed to be
	familiar with that document.		familiar with that document.
	This memo is intended to be parallel in structure to a companion		This memo is intended to be parallel in structure to a companion
	document for Packet Loss ("A One-way Packet Loss Metric for IPPM")		document for Packet Loss ("A One-way Packet Loss Metric for IPPM")
	[2].		[RFC2680].
	Although RFC 2119 was written with protocols in mind, the key words		Although [RFC2119] was written with protocols in mind, the key words
	are used in this document for similar reasons. They are used to		are used in this document for similar reasons. They are used to
	ensure the results of measurements from two different implementations		ensure the results of measurements from two different implementations
	are comparable, and to note instances when an implementation could		are comparable, and to note instances when an implementation could
	perturb the network.		perturb the network.
	The structure of the memo is as follows:		The structure of the memo is as follows:
	+ A 'singleton' analytic metric, called Type-P-One-way-Delay, will be		+ A 'singleton' analytic metric, called Type-P-One-way-Delay, will be
	introduced to measure a single observation of one-way delay.		introduced to measure a single observation of one-way delay.
	+ Using this singleton metric, a 'sample', called Type-P-One-way-		+ Using this singleton metric, a 'sample', called Type-P-One-way-
	Delay-Poisson-Stream, will be introduced to measure a sequence of		Delay-Poisson-Stream, will be introduced to measure a sequence of
	singleton delays measured at times taken from a Poisson process.		singleton delays sent at times taken from a Poisson process.
	+ Using this sample, several 'statistics' of the sample will be		+ Using this sample, several 'statistics' of the sample will be
	defined and discussed. This progression from singleton to sample to		defined and discussed. This progression from singleton to sample to
	statistics, with clear separation among them, is important.		statistics, with clear separation among them, is important.
	Whenever a technical term from the IPPM Framework document is first		Whenever a technical term from the IPPM Framework document is first
	used in this memo, it will be tagged with a trailing asterisk. For		used in this memo, it will be tagged with a trailing asterisk. For
	example, "term*" indicates that "term" is defined in the Framework.		example, "term*" indicates that "term" is defined in the Framework.
	2.1. Motivation		2.1. Motivation
	skipping to change at page 5, line 45		skipping to change at page 6, line 41
	+ In today's Internet, the path from a source to a destination may be		+ In today's Internet, the path from a source to a destination may be
	different than the path from the destination back to the source		different than the path from the destination back to the source
	("asymmetric paths"), such that different sequences of routers are		("asymmetric paths"), such that different sequences of routers are
	used for the forward and reverse paths. Therefore round-trip		used for the forward and reverse paths. Therefore round-trip
	measurements actually measure the performance of two distinct paths		measurements actually measure the performance of two distinct paths
	together. Measuring each path independently highlights the		together. Measuring each path independently highlights the
	performance difference between the two paths which may traverse		performance difference between the two paths which may traverse
	different Internet service providers, and even radically different		different Internet service providers, and even radically different
	types of networks (for example, research versus commodity networks,		types of networks (for example, research versus commodity networks,
	or ATM versus packet-over-SONET).		or networks with asymmetric link capacities, or wireless vs. wireline
			access).
	+ Even when the two paths are symmetric, they may have radically		+ Even when the two paths are symmetric, they may have radically
	different performance characteristics due to asymmetric queueing.		different performance characteristics due to asymmetric queueing.
	+ Performance of an application may depend mostly on the performance		+ Performance of an application may depend mostly on the performance
	in one direction. For example, a file transfer using TCP may depend		in one direction. For example, a TCP-based communication may
	more on the performance in the direction that data flows (queue		experience reduced throughput if congestion occurs in one direction
	occupation tends to grow in this direction, possibly dominating the		of its communication. Trouble shooting may be simplified if the
	round-trip delay), rather than the direction in which		congested direction of TCP transmission can be identified.
	acknowledgements travel.
	+ In quality-of-service (QoS) enabled networks, provisioning in one		+ In quality-of-service (QoS) enabled networks, provisioning in one
	direction may be radically different than provisioning in the reverse		direction may be radically different than provisioning in the reverse
	direction, and thus the QoS guarantees differ. Measuring the paths		direction, and thus the QoS guarantees differ. Measuring the paths
	independently allows the verification of both guarantees.		independently allows the verification of both guarantees.
	It is outside the scope of this document to say precisely how delay		It is outside the scope of this document to say precisely how delay
	metrics would be applied to specific problems.		metrics would be applied to specific problems.
	2.2. General Issues Regarding Time		2.2. General Issues Regarding Time
	skipping to change at page 8, line 30		skipping to change at page 9, line 30
	values.		values.
	+ Since delay values will often be as low as the 100 usec to 10 msec		+ Since delay values will often be as low as the 100 usec to 10 msec
	range, it will be important for Src and Dst to synchronize very		range, it will be important for Src and Dst to synchronize very
	closely. GPS systems afford one way to achieve synchronization to		closely. GPS systems afford one way to achieve synchronization to
	within several 10s of usec. Ordinary application of NTP may allow		within several 10s of usec. Ordinary application of NTP may allow
	synchronization to within several msec, but this depends on the		synchronization to within several msec, but this depends on the
	stability and symmetry of delay properties among those NTP agents		stability and symmetry of delay properties among those NTP agents
	used, and this delay is what we are trying to measure. A combination		used, and this delay is what we are trying to measure. A combination
	of some GPS-based NTP servers and a conservatively designed and		of some GPS-based NTP servers and a conservatively designed and
	deployed set of other NTP servers should yield good results, but this		deployed set of other NTP servers should yield good results. This
	is yet to be tested.		was tested in [RFC6808], where a GPS measurement system's results
			compared well with a GPS-based NTP synchronized system for the same
			intercontinental path.
	+ A given methodology will have to include a way to determine whether		+ A given methodology will have to include a way to determine whether
	a delay value is infinite or whether it is merely very large (and the		a delay value is infinite or whether it is merely very large (and the
	packet is yet to arrive at Dst). As noted by Mahdavi and Paxson [4],		packet is yet to arrive at Dst). As noted by Mahdavi and Paxson
	simple upper bounds (such as the 255 seconds theoretical upper bound		[RFC2678], simple upper bounds (such as the 255 seconds theoretical
	on the lifetimes of IP packets [5]) could be used, but good		upper bound on the lifetimes of IP packets [RFC0791]) could be used,
	engineering, including an understanding of packet lifetimes, will be		but good engineering, including an understanding of packet lifetimes,
	needed in practice. {Comment: Note that, for many applications of		will be needed in practice. {Comment: Note that, for many
	these metrics, the harm in treating a large delay as infinite might		applications of these metrics, the harm in treating a large delay as
	be zero or very small. A TCP data packet, for example, that arrives		infinite might be zero or very small. A TCP data packet, for
	only after several multiples of the RTT may as well have been lost.}		example, that arrives only after several multiples of the RTT may as
			well have been lost. See section 4.1.1 of [RFC6703] for examination
			of unusual packet delays and application performance estimation.}
	+ If the packet is duplicated along the path (or paths) so that		+ If the packet is duplicated along the path (or paths) so that
	multiple non-corrupt copies arrive at the destination, then the		multiple non-corrupt copies arrive at the destination, then the
	packet is counted as received, and the first copy to arrive		packet is counted as received, and the first copy to arrive
	determines the packet's one-way delay.		determines the packet's one-way delay.
	+ If the packet is fragmented and if, for whatever reason, reassembly		+ If the packet is fragmented and if, for whatever reason, reassembly
	does not occur, then the packet will be deemed lost.		does not occur, then the packet will be deemed lost.
			+ The packet is standard-formed, the default criteria for all metric
			definitions defined in Section 15 of [RFC2330], otherwise the packet
			will be deemed lost.
	3.6. Methodologies:		3.6. Methodologies:
	As with other Type-P-* metrics, the detailed methodology will depend		As with other Type-P-* metrics, the detailed methodology will depend
	on the Type-P (e.g., protocol number, UDP/TCP port number, size,		on the Type-P (e.g., protocol number, UDP/TCP port number, size,
	precedence).		precedence).
	Generally, for a given Type-P, the methodology would proceed as		Generally, for a given Type-P, the methodology would proceed as
	follows:		follows:
	+ Arrange that Src and Dst are synchronized; that is, that they have		+ Arrange that Src and Dst are synchronized; that is, that they have
	skipping to change at page 9, line 31		skipping to change at page 10, line 38
	filled with randomized bits to avoid a situation in which the		filled with randomized bits to avoid a situation in which the
	measured delay is lower than it would otherwise be due to compression		measured delay is lower than it would otherwise be due to compression
	techniques along the path. Note that use of transport layer		techniques along the path. Note that use of transport layer
	encryption will counteract the deployment of network-based analysis		encryption will counteract the deployment of network-based analysis
	and may reduce the adoption of payload optimizations like		and may reduce the adoption of payload optimizations like
	compression.		compression.
	+ At the Dst host, arrange to receive the packet.		+ At the Dst host, arrange to receive the packet.
	+ At the Src host, place a timestamp in the prepared Type-P packet,		+ At the Src host, place a timestamp in the prepared Type-P packet,
	and send it towards Dst.		and send it towards Dst (ideally minimizing time before sending).
	+ If the packet arrives within a reasonable period of time, take a		+ If the packet arrives within a reasonable period of time, take a
	timestamp as soon as possible upon the receipt of the packet. By		timestamp as soon as possible upon the receipt of the packet. By
	subtracting the two timestamps, an estimate of one-way delay can be		subtracting the two timestamps, an estimate of one-way delay can be
	computed. Error analysis of a given implementation of the method		computed. Error analysis of a given implementation of the method
	must take into account the closeness of synchronization between Src		must take into account the closeness of synchronization between Src
	and Dst. If the delay between Src's timestamp and the actual sending		and Dst. If the delay between Src's timestamp and the actual sending
	of the packet is known, then the estimate could be adjusted by		of the packet is known, then the estimate could be adjusted by
	subtracting this amount; uncertainty in this value must be taken into		subtracting this amount; uncertainty in this value must be taken into
	account in error analysis. Similarly, if the delay between the		account in error analysis. Similarly, if the delay between the
	actual receipt of the packet and Dst's timestamp is known, then the		actual receipt of the packet and Dst's timestamp is known, then the
	estimate could be adjusted by subtracting this amount; uncertainty in		estimate could be adjusted by subtracting this amount; uncertainty in
	this value must be taken into account in error analysis. See the		this value must be taken into account in error analysis. See the
	next section, "Errors and Uncertainties", for a more detailed		next section, "Errors and Uncertainties", for a more detailed
	discussion.		discussion.
	+ If the packet fails to arrive within a reasonable period of time,		+ If the packet fails to arrive within a reasonable period of time,
	the one-way delay is taken to be undefined (informally, infinite).		Tmax, the one-way delay is taken to be undefined (informally,
	Note that the threshold of 'reasonable' is a parameter of the		infinite). Note that the threshold of 'reasonable' is a parameter of
	methodology. These points are examined in detail in [RFC6703],		the metric. These points are examined in detail in [RFC6703],
	including analysis preferences to assign undefined delay to packets		including analysis preferences to assign undefined delay to packets
	that fail to arrive with the difficulties emerging from the informal		that fail to arrive with the difficulties emerging from the informal
	"infinite delay" assignment, and an estimation of an upper bound on		"infinite delay" assignment, and an estimation of an upper bound on
	waiting time for packets in transit. Further, enforcing a specific		waiting time for packets in transit. Further, enforcing a specific
	constant waiting time on stored singletons of one-way delay is		constant waiting time on stored singletons of one-way delay is
	compliant with this specification and may allow the results to serve		compliant with this specification and may allow the results to serve
	more than one reporting audience.		more than one reporting audience.
	Issues such as the packet format, the means by which Dst knows when		Issues such as the packet format, the means by which Dst knows when
	to expect the test packet, and the means by which Src and Dst are		to expect the test packet, and the means by which Src and Dst are
	skipping to change at page 12, line 40		skipping to change at page 13, line 46
	If the systematic error (the constant bias in measured values) can be		If the systematic error (the constant bias in measured values) can be
	determined, it can be compensated for in the reported results.		determined, it can be compensated for in the reported results.
	reported value = measured value - systematic error		reported value = measured value - systematic error
	therefore		therefore
	reported value = true value + random error		reported value = true value + random error
	The goal of calibration is to determine the systematic and random		The goal of calibration is to determine the systematic and random
	error generated by the instruments themselves in as much detail as		error generated by the hosts themselves in as much detail as
	possible. At a minimum, a bound ("e") should be found such that the		possible. At a minimum, a bound ("e") should be found such that the
	reported value is in the range (true value - e) to (true value + e)		reported value is in the range (true value - e) to (true value + e)
	at least 95 percent of the time. We call "e" the calibration error		at least 95 percent of the time. We call "e" the calibration error
	for the measurements. It represents the degree to which the values		for the measurements. It represents the degree to which the values
	produced by the measurement instrument are repeatable; that is, how		produced by the measurement host are repeatable; that is, how closely
	closely an actual delay of 30 ms is reported as 30 ms. {Comment: 95		an actual delay of 30 ms is reported as 30 ms. {Comment: 95 percent
	percent was chosen because (1) some confidence level is desirable to		was chosen because (1) some confidence level is desirable to be able
	be able to remove outliers, which will be found in measuring any		to remove outliers, which will be found in measuring any physical
	physical property; (2) a particular confidence level should be		property; (2) a particular confidence level should be specified so
	specified so that the results of independent implementations can be		that the results of independent implementations can be compared; and
	compared; and (3) even with a prototype user-level implementation,		(3) even with a prototype user-level implementation, 95% was loose
	95% was loose enough to exclude outliers.}		enough to exclude outliers.}
	From the discussion in the previous two sections, the error in		From the discussion in the previous two sections, the error in
	measurements could be bounded by determining all the individual		measurements could be bounded by determining all the individual
	uncertainties, and adding them together to form		uncertainties, and adding them together to form
	Esynch(t) + Rsource + Rdest + Hsource + Hdest.		Esynch(t) + Rsource + Rdest + Hsource + Hdest.
	However, reasonable bounds on both the clock-related uncertainty		However, reasonable bounds on both the clock-related uncertainty
	captured by the first three terms and the host-related uncertainty		captured by the first three terms and the host-related uncertainty
	captured by the last two terms should be possible by careful design		captured by the last two terms should be possible by careful design
	techniques and calibrating the instruments using a known, isolated,		techniques and calibrating the hosts using a known, isolated, network
	network in a lab.		in a lab.
	For example, the clock-related uncertainties are greatly reduced		For example, the clock-related uncertainties are greatly reduced
	through the use of a GPS time source. The sum of Esynch(t) + Rsource		through the use of a GPS time source. The sum of Esynch(t) + Rsource
	+ Rdest is small, and is also bounded for the duration of the		+ Rdest is small, and is also bounded for the duration of the
	measurement because of the global time source.		measurement because of the global time source.
	The host-related uncertainties, Hsource + Hdest, could be bounded by		The host-related uncertainties, Hsource + Hdest, could be bounded by
	connecting two instruments back-to-back with a high-speed serial link		connecting two hosts back-to-back with a high-speed serial link or
	or isolated LAN segment. In this case, repeated measurements are		isolated LAN segment. In this case, repeated measurements are
	measuring the same one-way delay.		measuring the same one-way delay.
	If the test packets are small, such a network connection has a		If the test packets are small, such a network connection has a
	minimal delay that may be approximated by zero. The measured delay		minimal delay that may be approximated by zero. The measured delay
	therefore contains only systematic and random error in the		therefore contains only systematic and random error in the
	instrumentation. The "average value" of repeated measurements is the		measurement hosts. The "average value" of repeated measurements is
	systematic error, and the variation is the random error.		the systematic error, and the variation is the random error.
	One way to compute the systematic error, and the random error to a		One way to compute the systematic error, and the random error to a
	95% confidence is to repeat the experiment many times - at least		95% confidence is to repeat the experiment many times - at least
	hundreds of tests. The systematic error would then be the median.		hundreds of tests. The systematic error would then be the median.
	The random error could then be found by removing the systematic error		The random error could then be found by removing the systematic error
	from the measured values. The 95% confidence interval would be the		from the measured values. The 95% confidence interval would be the
	range from the 2.5th percentile to the 97.5th percentile of these		range from the 2.5th percentile to the 97.5th percentile of these
	deviations from the true value. The calibration error "e" could then		deviations from the true value. The calibration error "e" could then
	be taken to be the largest absolute value of these two numbers, plus		be taken to be the largest absolute value of these two numbers, plus
	the clock-related uncertainty. {Comment: as described, this bound is		the clock-related uncertainty. {Comment: as described, this bound is
	relatively loose since the uncertainties are added, and the absolute		relatively loose since the uncertainties are added, and the absolute
	value of the largest deviation is used. As long as the resulting		value of the largest deviation is used. As long as the resulting
	value is not a significant fraction of the measured values, it is a		value is not a significant fraction of the measured values, it is a
	reasonable bound. If the resulting value is a significant fraction		reasonable bound. If the resulting value is a significant fraction
	of the measured values, then more exact methods will be needed to		of the measured values, then more exact methods will be needed to
	compute the calibration error.}		compute the calibration error.}
	Note that random error is a function of measurement load. For		Note that random error is a function of measurement load. For
	example, if many paths will be measured by one instrument, this might		example, if many paths will be measured by one host, this might
	increase interrupts, process scheduling, and disk I/O (for example,		increase interrupts, process scheduling, and disk I/O (for example,
	recording the measurements), all of which may increase the random		recording the measurements), all of which may increase the random
	error in measured singletons. Therefore, in addition to minimal load		error in measured singletons. Therefore, in addition to minimal load
	measurements to find the systematic error, calibration measurements		measurements to find the systematic error, calibration measurements
	should be performed with the same measurement load that the		should be performed with the same measurement load that the hosts
	instruments will see in the field.		will see in the field.
	We wish to reiterate that this statistical treatment refers to the		We wish to reiterate that this statistical treatment refers to the
	calibration of the instrument; it is used to "calibrate the meter		calibration of the host; it is used to "calibrate the meter stick"
	stick" and say how well the meter stick reflects reality.		and say how well the meter stick reflects reality.
	In addition to calibrating the instruments for finite one-way delay,		In addition to calibrating the hosts for finite one-way delay, two
	two checks should be made to ensure that packets reported as losses		checks should be made to ensure that packets reported as losses were
	were really lost. First, the threshold for loss should be verified.		really lost. First, the threshold for loss should be verified. In
	In particular, ensure the "reasonable" threshold is reasonable: that		particular, ensure the "reasonable" threshold is reasonable: that it
	it is very unlikely a packet will arrive after the threshold value,		is very unlikely a packet will arrive after the threshold value, and
	and therefore the number of packets lost over an interval is not		therefore the number of packets lost over an interval is not
	sensitive to the error bound on measurements. Second, consider the		sensitive to the error bound on measurements. Second, consider the
	possibility that a packet arrives at the network interface, but is		possibility that a packet arrives at the network interface, but is
	lost due to congestion on that interface or to other resource		lost due to congestion on that interface or to other resource
	exhaustion (e.g. buffers) in the instrument.		exhaustion (e.g. buffers) in the host.
	3.8. Reporting the metric:		3.8. Reporting the metric:
	The calibration and context in which the metric is measured MUST be		The calibration and context in which the metric is measured MUST be
	carefully considered, and SHOULD always be reported along with metric		carefully considered, and SHOULD always be reported along with metric
	results. We now present four items to consider: the Type-P of test		results. We now present four items to consider: the Type-P of test
	packets, the threshold of infinite delay (if any), error calibration,		packets, the threshold of infinite delay (if any), error calibration,
	and the path traversed by the test packets. This list is not		and the path traversed by the test packets. This list is not
	exhaustive; any additional information that could be useful in		exhaustive; any additional information that could be useful in
	interpreting applications of the metrics should also be reported (see		interpreting applications of the metrics should also be reported (see
	[RFC6703] for extensive discussion of reporting considerations for		[RFC6703] for extensive discussion of reporting considerations for
	different audiences).		different audiences).
	3.8.1. Type-P		3.8.1. Type-P
	As noted in the Framework document [1], the value of the metric may		As noted in the Framework document [RFC2330], the value of the metric
	depend on the type of IP packets used to make the measurement, or		may depend on the type of IP packets used to make the measurement, or
	"type-P". The value of Type-P-One-way-Delay could change if the		"type-P". The value of Type-P-One-way-Delay could change if the
	protocol (UDP or TCP), port number, size, or arrangement for special		protocol (UDP or TCP), port number, size, or arrangement for special
	treatment (e.g., IP precedence or RSVP) changes. The exact Type-P		treatment (e.g., IP precedence or RSVP) changes. The exact Type-P
	used to make the measurements MUST be accurately reported.		used to make the measurements MUST be accurately reported.
	3.8.2. Loss Threshold		3.8.2. Loss Threshold
	In addition, the threshold (or methodology to distinguish) between a		In addition, the threshold (or methodology to distinguish) between a
	large finite delay and loss MUST be reported.		large finite delay and loss MUST be reported.
	skipping to change at page 15, line 16		skipping to change at page 16, line 21
	+ If the systematic error can be determined, it SHOULD be removed		+ If the systematic error can be determined, it SHOULD be removed
	from the measured values.		from the measured values.
	+ You SHOULD also report the calibration error, e, such that the true		+ You SHOULD also report the calibration error, e, such that the true
	value is the reported value plus or minus e, with 95% confidence (see		value is the reported value plus or minus e, with 95% confidence (see
	the last section.)		the last section.)
	+ If possible, the conditions under which a test packet with finite		+ If possible, the conditions under which a test packet with finite
	delay is reported as lost due to resource exhaustion on the		delay is reported as lost due to resource exhaustion on the
	measurement instrument SHOULD be reported.		measurement host SHOULD be reported.
	3.8.4. Path		3.8.4. Path
	Finally, the path traversed by the packet SHOULD be reported, if		Finally, the path traversed by the packet SHOULD be reported, if
	possible. In general it is impractical to know the precise path a		possible. In general it is impractical to know the precise path a
	given packet takes through the network. The precise path may be		given packet takes through the network. The precise path may be
	known for certain Type-P on short or stable paths. If Type-P		known for certain Type-P on short or stable paths. If Type-P
	includes the record route (or loose-source route) option in the IP		includes the record route (or loose-source route) option in the IP
	header, and the path is short enough, and all routers* on the path		header, and the path is short enough, and all routers* on the path
	support record (or loose-source) route, then the path will be		support record (or loose-source) route, then the path will be
	skipping to change at page 15, line 47		skipping to change at page 17, line 4
	4. A Definition for Samples of One-way Delay		4. A Definition for Samples of One-way Delay
	Given the singleton metric Type-P-One-way-Delay, we now define one		Given the singleton metric Type-P-One-way-Delay, we now define one
	particular sample of such singletons. The idea of the sample is to		particular sample of such singletons. The idea of the sample is to
	select a particular binding of the parameters Src, Dst, and Type-P,		select a particular binding of the parameters Src, Dst, and Type-P,
	then define a sample of values of parameter T. The means for		then define a sample of values of parameter T. The means for
	defining the values of T is to select a beginning time T0, a final		defining the values of T is to select a beginning time T0, a final
	time Tf, and an average rate lambda, then define a pseudo-random		time Tf, and an average rate lambda, then define a pseudo-random
	Poisson process of rate lambda, whose values fall between T0 and Tf.		Poisson process of rate lambda, whose values fall between T0 and Tf.
	The time interval between successive values of T will then average 1/		The time interval between successive values of T will then average 1/
	lambda.		lambda.
	{Comment: Note that Poisson sampling is only one way of defining a		Note that Poisson sampling is only one way of defining a sample.
	sample. Poisson has the advantage of limiting bias, but other		Poisson has the advantage of limiting bias, but other methods of
	methods of sampling might be appropriate for different situations.		sampling will be appropriate for different situations. For example,
			a truncated Poisson distribution may be needed to avoid reactive
	We encourage others who find such appropriate cases to use this		network state changes during intervals of inactivity, see section 4.6
	general framework and submit their sampling method for		of [RFC7321]. Sometimes, the goal is sampling with a known bias, and
	standardization.}		[RFC3432] describes a method for periodic sampling with random start
			times.
	>>> Editor proposal: Add ref to RFC 3432 Periodic sampling above.
	4.1. Metric Name:		4.1. Metric Name:
	Type-P-One-way-Delay-Poisson-Stream		Type-P-One-way-Delay-Poisson-Stream
	4.2. Metric Parameters:		4.2. Metric Parameters:
	+ Src, the IP address of a host		+ Src, the IP address of a host
	+ Dst, the IP address of a host		+ Dst, the IP address of a host
	+ T0, a time		+ T0, a time
	+ Tf, a time		+ Tf, a time
	+ lambda, a rate in reciprocal seconds		+ Tmax, a loss threshold waiting time
			+ lambda, a rate in reciprocal seconds (or parameters for another
			distribution)
	4.3. Metric Units:		4.3. Metric Units:
	A sequence of pairs; the elements of each pair are:		A sequence of pairs; the elements of each pair are:
	+ T, a time, and		+ T, a time, and
	+ dT, either a real number or an undefined number of seconds.		+ dT, either a real number or an undefined number of seconds.
	The values of T in the sequence are monotonic increasing. Note that		The values of T in the sequence are monotonic increasing. Note that
	skipping to change at page 17, line 8		skipping to change at page 18, line 13
	ending at or after Tf. Those time values greater than or equal to T0		ending at or after Tf. Those time values greater than or equal to T0
	and less than or equal to Tf are then selected. At each of the times		and less than or equal to Tf are then selected. At each of the times
	in this process, we obtain the value of Type-P-One-way-Delay at this		in this process, we obtain the value of Type-P-One-way-Delay at this
	time. The value of the sample is the sequence made up of the		time. The value of the sample is the sequence made up of the
	resulting <time, delay> pairs. If there are no such pairs, the		resulting <time, delay> pairs. If there are no such pairs, the
	sequence is of length zero and the sample is said to be empty.		sequence is of length zero and the sample is said to be empty.
	4.5. Discussion:		4.5. Discussion:
	The reader should be familiar with the in-depth discussion of Poisson		The reader should be familiar with the in-depth discussion of Poisson
	sampling in the Framework document [1], which includes methods to		sampling in the Framework document [RFC2330], which includes methods
	compute and verify the pseudo-random Poisson process.		to compute and verify the pseudo-random Poisson process.
	We specifically do not constrain the value of lambda, except to note		We specifically do not constrain the value of lambda, except to note
	the extremes. If the rate is too large, then the measurement traffic		the extremes. If the rate is too large, then the measurement traffic
	will perturb the network, and itself cause congestion. If the rate		will perturb the network, and itself cause congestion. If the rate
	is too small, then you might not capture interesting network		is too small, then you might not capture interesting network
	behavior. {Comment: We expect to document our experiences with, and		behavior. {Comment: We expect to document our experiences with, and
	suggestions for, lambda elsewhere, culminating in a "best current		suggestions for, lambda elsewhere, culminating in a "best current
	practices" document.}		practices" document.}
	Since a pseudo-random number sequence is employed, the sequence of		Since a pseudo-random number sequence is employed, the sequence of
	skipping to change at page 17, line 47		skipping to change at page 19, line 4
	new time values T0' and Tf' such that T0 <= T0' <= Tf' <= Tf, the		new time values T0' and Tf' such that T0 <= T0' <= Tf' <= Tf, the
	subsequence of the given sample whose time values fall between T0'		subsequence of the given sample whose time values fall between T0'
	and Tf' are also a valid Type-P-One-way-Delay-Poisson-Stream sample.		and Tf' are also a valid Type-P-One-way-Delay-Poisson-Stream sample.
	4.6. Methodologies:		4.6. Methodologies:
	The methodologies follow directly from:		The methodologies follow directly from:
	+ the selection of specific times, using the specified Poisson		+ the selection of specific times, using the specified Poisson
	arrival process, and		arrival process, and
	+ the methodologies discussion already given for the singleton Type-		+ the methodologies discussion already given for the singleton Type-
	P-One-way-Delay metric.		P-One-way-Delay metric.
	Care must, of course, be given to correctly handle out-of-order		Care must, of course, be given to correctly handle out-of-order
	arrival of test packets; it is possible that the Src could send one		arrival of test packets; it is possible that the Src could send one
	test packet at TS[i], then send a second one (later) at TS[i+1],		test packet at TS[i], then send a second one (later) at TS[i+1],
	while the Dst could receive the second test packet at TR[i+1], and		while the Dst could receive the second test packet at TR[i+1], and
	then receive the first one (later) at TR[i].		then receive the first one (later) at TR[i]. Metrics for reordering
			may be found in [RFC4737].
	>>> Editor proposal: Add ref to RFC 4737 Reordering metric above.
	4.7. Errors and Uncertainties:		4.7. Errors and Uncertainties:
	In addition to sources of errors and uncertainties associated with		In addition to sources of errors and uncertainties associated with
	methods employed to measure the singleton values that make up the		methods employed to measure the singleton values that make up the
	sample, care must be given to analyze the accuracy of the Poisson		sample, care must be given to analyze the accuracy of the Poisson
	process with respect to the wire-times of the sending of the test		process with respect to the wire-times of the sending of the test
	packets. Problems with this process could be caused by several		packets. Problems with this process could be caused by several
	things, including problems with the pseudo-random number techniques		things, including problems with the pseudo-random number techniques
	used to generate the Poisson arrival process, or with jitter in the		used to generate the Poisson arrival process, or with jitter in the
	skipping to change at page 19, line 18		skipping to change at page 20, line 23
	<T3, undefined>		<T3, undefined>
	<T4, 90 msec>		<T4, 90 msec>
	<T5, 500 msec>		<T5, 500 msec>
	>		>
	Then the 50th percentile would be 110 msec, since 90 msec and 100		Then the 50th percentile would be 110 msec, since 90 msec and 100
	msec are smaller and 500 msec and 'undefined' are larger. See		msec are smaller and 500 msec and 'undefined' are larger. See
	Section 11.3 of [1] for computing percentiles.		Section 11.3 of [RFC2330] for computing percentiles.
	Note that if the possibility that a packet with finite delay is		Note that if the possibility that a packet with finite delay is
	reported as lost is significant, then a high percentile (90th or		reported as lost is significant, then a high percentile (90th or
	95th) might be reported as infinite instead of finite.		95th) might be reported as infinite instead of finite.
	5.2. Type-P-One-way-Delay-Median		5.2. Type-P-One-way-Delay-Median
	Given a Type-P-One-way-Delay-Poisson-Stream, the median of all the dT		Given a Type-P-One-way-Delay-Poisson-Stream, the median of all the dT
	values in the Stream. In computing the median, undefined values are		values in the Stream. In computing the median, undefined values are
	treated as infinitely large. As with Type-P-One-way-Delay-		treated as infinitely large. As with Type-P-One-way-Delay-
	skipping to change at page 20, line 43		skipping to change at page 21, line 52
	packets into the network. The measurement parameters MUST be		packets into the network. The measurement parameters MUST be
	carefully selected so that the measurements inject trivial amounts of		carefully selected so that the measurements inject trivial amounts of
	additional traffic into the networks they measure. If they inject		additional traffic into the networks they measure. If they inject
	"too much" traffic, they can skew the results of the measurement, and		"too much" traffic, they can skew the results of the measurement, and
	in extreme cases cause congestion and denial of service.		in extreme cases cause congestion and denial of service.
	The measurements themselves could be harmed by routers giving		The measurements themselves could be harmed by routers giving
	measurement traffic a different priority than "normal" traffic, or by		measurement traffic a different priority than "normal" traffic, or by
	an attacker injecting artificial measurement traffic. If routers can		an attacker injecting artificial measurement traffic. If routers can
	recognize measurement traffic and treat it separately, the		recognize measurement traffic and treat it separately, the
	measurements will not reflect actual user traffic. If an attacker		measurements will not reflect actual user traffic. Therefore, the
	injects artificial traffic that is accepted as legitimate, the loss		measurement methodologies SHOULD include appropriate techniques to
	rate will be artificially lowered. Therefore, the measurement		reduce the probability measurement traffic can be distinguished from
	methodologies SHOULD include appropriate techniques to reduce the		"normal" traffic.
	probability measurement traffic can be distinguished from "normal"
	traffic. Authentication techniques, such as digital signatures, may		If an attacker injects packets emulating traffic that are accepted as
	be used where appropriate to guard against injected traffic attacks.		legitimate, the loss ratio or other measured values could be
			corrupted. Authentication techniques, such as digital signatures,
			may be used where appropriate to guard against injected traffic
			attacks.
	The privacy concerns of network measurement are limited by the active		The privacy concerns of network measurement are limited by the active
	measurements described in this memo. Unlike passive measurements,		measurements described in this memo. Unlike passive measurements,
	there can be no release of existing user data.		there can be no release of existing user data.
	7. IANA Considerations		7. IANA Considerations
	This memo makes no requests of IANA.		This memo makes no requests of IANA.
	8. Acknowledgements		8. Acknowledgements
	Special thanks are due to Vern Paxson of Lawrence Berkeley Labs for		Special thanks are due to Vern Paxson of Lawrence Berkeley Labs for
	his helpful comments on issues of clock uncertainty and statistics.		his helpful comments on issues of clock uncertainty and statistics.
	Thanks also to Garry Couch, Will Leland, Andy Scherrer, Sean Shapira,		Thanks also to Garry Couch, Will Leland, Andy Scherrer, Sean Shapira,
	and Roland Wittig for several useful suggestions.		and Roland Wittig for several useful suggestions.
	9. Refetrences (temporary)		9. References
	[1] Paxson, V., Almes, G., Mahdavi, J. and M. Mathis, "Framework for
	IP Performance Metrics", RFC 2330, May 1998.
	[2] Almes, G., Kalidindi, S. and M. Zekauskas, "A One-way Packet
	Loss Metric for IPPM", RFC 2680, September 1999.
	[3] Mills, D., "Network Time Protocol (v3)", RFC 1305, April 1992.
	[4] Mahdavi J. and V. Paxson, "IPPM Metrics for Measuring
	Connectivity", RFC 2678, September 1999.
	[5] Postel, J., "Internet Protocol", STD 5, RFC 791, September 1981.
	[6] Bradner, S., "Key words for use in RFCs to Indicate Requirement
	Levels", BCP 14, RFC 2119, March 1997.
	[7] Bradner, S., "The Internet Standards Process -- Revision 3", BCP
	9, RFC 2026, October 1996.
	10. References		9.1. Normative References
	10.1. Normative References		[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September
			1981.
	[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, May		"Framework for IP Performance Metrics", RFC 2330, May
	1998.		1998.
			[RFC2678] Mahdavi, J. and V. Paxson, "IPPM Metrics for Measuring
			Connectivity", RFC 2678, September 1999.
	[RFC2679] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way		[RFC2679] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
	Delay Metric for IPPM", RFC 2679, September 1999.		Delay Metric for IPPM", RFC 2679, September 1999.
	[RFC2680] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way		[RFC2680] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
	Packet Loss Metric for IPPM", RFC 2680, September 1999.		Packet Loss Metric for IPPM", RFC 2680, September 1999.
	[RFC3432] Raisanen, V., Grotefeld, G., and A. Morton, "Network		[RFC3432] Raisanen, V., Grotefeld, G., and A. Morton, "Network
	performance measurement with periodic streams", RFC 3432,		performance measurement with periodic streams", RFC 3432,
	November 2002.		November 2002.
	skipping to change at page 22, line 34		skipping to change at page 23, line 27
	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.
	[RFC5835] Morton, A. and S. Van den Berghe, "Framework for Metric		[RFC5835] Morton, A. and S. Van den Berghe, "Framework for Metric
	Composition", RFC 5835, April 2010.		Composition", RFC 5835, April 2010.
			[RFC5905] Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network
			Time Protocol Version 4: Protocol and Algorithms
			Specification", RFC 5905, June 2010.
	[RFC6049] Morton, A. and E. Stephan, "Spatial Composition of		[RFC6049] Morton, A. and E. Stephan, "Spatial Composition of
	Metrics", RFC 6049, January 2011.		Metrics", RFC 6049, January 2011.
	[RFC6576] Geib, R., Morton, A., Fardid, R., and A. Steinmitz, "IP		[RFC6576] Geib, R., Morton, A., Fardid, R., and A. Steinmitz, "IP
	Performance Metrics (IPPM) Standard Advancement Testing",		Performance Metrics (IPPM) Standard Advancement Testing",
	BCP 176, RFC 6576, March 2012.		BCP 176, RFC 6576, March 2012.
	[RFC6703] Morton, A., Ramachandran, G., and G. Maguluri, "Reporting		[RFC6703] Morton, A., Ramachandran, G., and G. Maguluri, "Reporting
	IP Network Performance Metrics: Different Points of View",		IP Network Performance Metrics: Different Points of View",
	RFC 6703, August 2012.		RFC 6703, August 2012.
	10.2. Informative References		[RFC7321] McGrew, D. and P. Hoffman, "Cryptographic Algorithm
			Implementation Requirements and Usage Guidance for
			Encapsulating Security Payload (ESP) and Authentication
			Header (AH)", RFC 7321, August 2014.
			9.2. 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, May		University of Washington, Technical Report No. 81, May
	1986.		1986.
	[I-D.ietf-ippm-testplan-rfc2679]		[I-D.ietf-ippm-testplan-rfc2679]
	Ciavattone, L., Geib, R., Morton, A., and M. Wieser, "Test		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", draft-ietf-ippm-testplan-rfc2679-03		Standards Track", draft-ietf-ippm-testplan-rfc2679-03
	(work in progress), September 2012.		(work in progress), September 2012.
	[RFC3931] Lau, J., Townsley, M., and I. Goyret, "Layer Two Tunneling		[RFC3931] Lau, J., Townsley, M., and I. Goyret, "Layer Two Tunneling
	Protocol - Version 3 (L2TPv3)", RFC 3931, March 2005.		Protocol - Version 3 (L2TPv3)", RFC 3931, March 2005.
			[RFC4737] Morton, A., Ciavattone, L., Ramachandran, G., Shalunov,
			S., and J. Perser, "Packet Reordering Metrics", RFC 4737,
			November 2006.
			[RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New
			Performance Metric Development", BCP 170, RFC 6390,
			October 2011.
			[RFC6808] Ciavattone, L., Geib, R., Morton, A., and M. Wieser, "Test
			Plan and Results Supporting Advancement of RFC 2679 on the
			Standards Track", RFC 6808, December 2012.
	Authors' Addresses		Authors' Addresses
	Guy Almes		Guy Almes
	Texas A&M		Texas A&M
			Email: galmes@tamu.edu
	Sunil Kalidindi		Sunil Kalidindi
	Ixia		Ixia
			Email: skalidindi@ixiacom.com
	Matt Zekauskas		Matt Zekauskas
	Internet2		Internet2
	Email: matt@internet2.edu		Email: matt@internet2.edu
	Al Morton (editor)		Al Morton (editor)
	AT&T Labs		AT&T Labs
	200 Laurel Avenue South		200 Laurel Avenue South
	Middletown, NJ 07748		Middletown, NJ 07748
	USA		USA
End of changes. 54 change blocks.
	177 lines changed or deleted		243 lines changed or added
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