draft-ietf-bmwg-dsmterm-03.txt		draft-ietf-bmwg-dsmterm-04.txt
	Network Working Group Jerry Perser		Network Working Group Jerry Perser
	INTERNET-DRAFT Spirent		INTERNET-DRAFT Spirent
	Expires in: December 2002 David Newman		Expires in: April 2003 David Newman
	Network Test		Network Test
	Sumit Khurana		Sumit Khurana
	Telcordia		Telcordia
	Shobha Erramilli		Shobha Erramilli
	QNetworx		QNetworx
	Scott Poretsky		Scott Poretsky
	Avici Systems		Avici Systems
	June 2002		October 2002
	Terminology for Benchmarking Network-layer		Terminology for Benchmarking Network-layer
	Traffic Control Mechanisms		Traffic Control Mechanisms
	<draft-ietf-bmwg-dsmterm-03.txt>		<draft-ietf-bmwg-dsmterm-04.txt>
	Status of this Memo		Status of this Memo
	This document is an Internet-Draft and is in full conformance with		This document is an Internet-Draft and is in full conformance with
	all provisions of Section 10 of RFC2026.		all provisions of Section 10 of RFC2026.
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF), its areas, and its working groups. Note that		Task Force (IETF), its areas, and its working groups. Note that
	other groups may also distribute working documents as Internet-		other groups may also distribute working documents as Internet-
	Drafts.		Drafts.
	skipping to change at page 2, line 10		skipping to change at page 2, line 10
	3.1.3 Congestion .............................................4		3.1.3 Congestion .............................................4
	3.1.4 Congestion Management ..................................5		3.1.4 Congestion Management ..................................5
	3.1.5 Flow ...................................................6		3.1.5 Flow ...................................................6
	3.2 Measurement Terms		3.2 Measurement Terms
	Network-layer Traffic Control Mechanisms		Network-layer Traffic Control Mechanisms
	3.2.1 Channel Capacity .......................................7		3.2.1 Channel Capacity .......................................7
	3.2.2 Conforming .............................................7		3.2.2 Conforming .............................................7
	3.2.3 Nonconforming ..........................................8		3.2.3 Nonconforming ..........................................8
	3.2.4 Delay ..................................................8		3.2.4 Delay ..................................................8
	3.2.6 Undifferentiated Response ................................9		3.2.5 Jitter .................................................9
			3.2.6 Undifferentiated Response .............................10
	3.3 Sequence Tracking		3.3 Sequence Tracking
	3.3.1 In-sequence Packet .....................................9		3.3.1 In-sequence Packet ....................................10
	3.3.2 Out-of-order Packet ...................................10		3.3.2 Out-of-order Packet ...................................11
	3.3.3 Duplicate Packet ......................................11		3.3.3 Duplicate Packet ......................................11
	3.3.4 Stream ................................................11		3.3.4 Stream ................................................12
	3.3.5 Test Sequence number .................................12		3.3.5 Test Sequence number .................................12
	3.4 Vectors ...................................................12		3.4 Vectors ...................................................13
	3.4.1 Intended Vector .......................................12		3.4.1 Intended Vector .......................................13
	3.4.2 Offered Vector ........................................13		3.4.2 Offered Vector ........................................14
	3.4.3 Expected Vectors		3.4.3 Expected Vectors
	3.4.3.1 Expected Forwarding Vector ........................13		3.4.3.1 Expected Forwarding Vector ........................14
	3.4.3.2 Expected Loss Vector ..............................14		3.4.3.2 Expected Loss Vector ..............................15
	3.4.3.3 Expected Sequence Vector ..........................14		3.4.3.3 Expected Sequence Vector ..........................16
	3.4.3.4 Expected Instantaneous Delay Vector ...............15		3.4.3.4 Expected Instantaneous Delay Vector ...............16
	3.4.3.5 Expected Average Delay Vector .....................16		3.4.3.5 Expected Average Delay Vector .....................17
	3.4.3.6 Expected Maximum Delay Vector .....................17		3.4.3.6 Expected Maximum Delay Vector .....................17
	3.4.3.7 Expected Minimum Delay Vector .....................17		3.4.3.7 Expected Minimum Delay Vector .....................18
	3.4.3.8 Expected Instantaneous Delay Variation Vector .....18		3.4.3.8 Expected Instantaneous Jitter Vector ..............19
	3.4.3.9 Expected Average Delay Variation Vector ...........19		3.4.3.9 Expected Average Jitter Vector ....................19
	3.4.3.10 Expected Peak-to-peak Delay Variation Vector .....19		3.4.3.10 Expected Peak-to-peak Jitter Vector ..............20
	3.4.4 Output Vectors		3.4.4 Output Vectors
	3.4.4.1 Forwarding Vector .................................20		3.4.4.1 Forwarding Vector .................................21
	3.4.4.2 Loss Vector .......................................20		3.4.4.2 Loss Vector .......................................21
	3.4.4.3 Sequence Vector ...................................21		3.4.4.3 Sequence Vector ...................................22
	3.4.4.4 Instantaneous Delay Vector ........................22		3.4.4.4 Instantaneous Delay Vector ........................23
	3.4.4.5 Average Delay Vector ..............................23		3.4.4.5 Average Delay Vector ..............................24
	3.4.4.6 Maximum Delay Vector ..............................23		3.4.4.6 Maximum Delay Vector ..............................25
	3.4.4.7 Minimum Delay Vector ..............................24		3.4.4.7 Minimum Delay Vector ..............................25
	3.4.4.8 Instantaneous Delay Variation Vector ..............25		3.4.4.8 Instantaneous Jitter Vector .......................26
	3.4.4.9 Average Delay Variation Vector ....................26		3.4.4.9 Average Jitter Vector .............................27
	3.4.4.10 Peak-to-peak Delay Variation Vector ..............27		3.4.4.10 Peak-to-peak Jitter Vector .......................28
	4. Security Considerations ....................................28		4. Security Considerations ....................................29
	5. References .................................................28		5. References .................................................29
	6. Author's Address ...........................................29		6. Author's Address ...........................................30
	7. Full Copyright Statement ...................................30		7. Full Copyright Statement ...................................31
	1. Introduction		1. Introduction
	This document describes terminology for the benchmarking of		This document describes terminology for the benchmarking of
	devices that implement traffic control based on IP precedence or		devices that implement traffic control based on IP precedence or
	diff-serv code point criteria.		diff-serv code point criteria.
	New terminology is needed because most existing measurements		New terminology is needed because most existing measurements
	assume the absence of congestion and only a single per-hop-		assume the absence of congestion and only a single per-hop-
			Network-layer Traffic Control Mechanisms
	behavior. This document introduces several new terms that will		behavior. This document introduces several new terms that will
	allow measurements to be taken during periods of congestion.		allow measurements to be taken during periods of congestion.
	Network-layer Traffic Control Mechanisms
	Another key difference from existing terminology is the definition		Another key difference from existing terminology is the definition
	of measurements as observed on egress as well as ingress of a		of measurements as observed on egress as well as ingress of a
	device/system under test. Again, the existence of congestion		device/system under test. Again, the existence of congestion
	requires the addition of egress measurements as well as those		requires the addition of egress measurements as well as those
	taken on ingress; without observing traffic leaving a		taken on ingress; without observing traffic leaving a
	device/system it is not possible to say whether traffic-control		device/system it is not possible to say whether traffic-control
	mechanisms effectively dealt with congestion.		mechanisms effectively dealt with congestion.
	The principal measurements introduced in this document are vectors		The principal measurements introduced in this document are vectors
	for rate, delay, and jitter, all of which can be observed with or		for rate, delay, and jitter, all of which can be observed with or
	skipping to change at page 3, line 53		skipping to change at page 4, line 4
	"OPTIONAL" in this document are to be interpreted as described in		"OPTIONAL" in this document are to be interpreted as described in
	RFC 2119.		RFC 2119.
	3. Term definitions		3. Term definitions
	3.1 Configuration Terms		3.1 Configuration Terms
	3.1.1 Classification		3.1.1 Classification
	Definition:		Definition:
	Selection of packets based on the contents of packet header
	according to defined rules.
	Network-layer Traffic Control Mechanisms		Network-layer Traffic Control Mechanisms
			Selection of packets based on the contents of packet header
			according to defined rules.
	Discussion:		Discussion:
	Packets can be selected based on the DS field or IP		Packets can be selected based on the DS field or IP
	Precedence in the packet header. Classification can also be		Precedence in the packet header. Classification can also be
	based on Multi-Field (MF) criteria such as IP Source and		based on Multi-Field (MF) criteria such as IP Source and
	destination addresses, protocol and port number.		destination addresses, protocol and port number.
	Classification determines the per-hop behaviors and traffic		Classification determines the per-hop behaviors and traffic
	conditioning functions such as shaping and dropping that are		conditioning functions such as shaping and dropping that are
	to be applied to the packet.		to be applied to the packet.
	skipping to change at page 4, line 50		skipping to change at page 4, line 53
	Measurement Units:		Measurement Units:
	n/a		n/a
	See Also:		See Also:
	3.1.3 Congestion		3.1.3 Congestion
	Definition:		Definition:
	A condition in which one or more egress interfaces are		A condition in which one or more egress interfaces are
	offered more packets than are forwarded at any given instant.		offered more packets than are forwarded.
	Discussion:		Discussion:
	This condition is a superset of the overload definition [2].
	The overload definition assumes the congestion is introduced
	Network-layer Traffic Control Mechanisms		Network-layer Traffic Control Mechanisms
			This condition is a superset of the overload definition [2].
			The overload definition assumes the congestion is introduced
	strictly by the tester on ingress of a DUT/SUT. That may or		strictly by the tester on ingress of a DUT/SUT. That may or
	may not be the case here.		may not be the case here.
	Another difference between congestion and overload occurs		Another difference between congestion and overload occurs
	when the SUT comprises multiple elements, in that congestion		when the SUT comprises multiple elements, in that congestion
	may occur at multiple points. Consider an SUT comprising		may occur at multiple points. Consider an SUT comprising
	multiple edge devices exchanging traffic with a single core		multiple edge devices exchanging traffic with a single core
	device. Depending on traffic patterns, the edge devices may		device. Depending on traffic patterns, the edge devices may
	induce congestion on multiple egress interfaces on the core		induce congestion on multiple egress interfaces on the core
	device. In contrast, overload [1] deals only with overload on		device. In contrast, overload [1] deals only with overload on
	ingress.		ingress.
			Throughput [1] defines the lower boundary of congestion.
			Throughput is the maximum offered rate with no congestion.
			At offered rates above throughput, the DUT/SUT is considered
			congested.
	Ingress observations alone are not sufficient to cover all		Ingress observations alone are not sufficient to cover all
	cases in which congestion may occur. A device with an		cases in which congestion may occur. A device with an
	infinite amount of memory could buffer an infinite amount of		infinite amount of memory could buffer an infinite amount of
	packets, and eventually forward all of them. However, these		packets, and eventually forward all of them. However, these
	packets may or may not be forwarded during the test duration.		packets may or may not be forwarded during the test duration.
	Even though ingress interfaces accept all packets without		Even though ingress interfaces accept all packets without
	loss, this hypothetical device may still be congested.		loss, this hypothetical device may still be congested.
	The definition presented here explicitly defines congestion		The definition presented here explicitly defines congestion
	as an event observable on egress interfaces. Regardless of		as an event observable on egress interfaces. Regardless of
	internal architecture, any device that cannot forward packets		internal architecture, any device that cannot forward packets
	on one or more egress interfaces is congested.		on one or more egress interfaces is congested.
	Measurement units:		Measurement units:
	n/a		none
	See Also:		See Also:
			Gateway Congestion Control Survey [8]
	3.1.4 Congestion Management		3.1.4 Congestion Management
	Definition:		Definition:
	An implementation of one or more per-hop-behaviors to avoid		An implementation of one or more per-hop-behaviors to avoid
	or minimize the condition of congestion.		or minimize the condition of congestion.
	Discussion:		Discussion:
	Congestion management may seek either to control congestion		Congestion management may seek either to control congestion
	or avoid it altogether. Such mechanisms classify packets		or avoid it altogether. Such mechanisms classify packets
	based upon IP Precedence or DSCP settings in a packet's IP		based upon IP Precedence or DSCP settings in a packet's IP
	header.		header.
			Network-layer Traffic Control Mechanisms
	Congestion avoidance mechanisms seek to prevent congestion		Congestion avoidance mechanisms seek to prevent congestion
	before it actually occurs.		before it actually occurs.
	Congestion control mechanisms gives one or flows (with a		Congestion control mechanisms gives one or flows (with a
	discrete IP Precedence or DSCP value) preferential treatment		discrete IP Precedence or DSCP value) preferential treatment
	over other classes during periods of congestion.		over other classes during periods of congestion.
	Measurement units:		Measurement units:
	n/a		n/a
	Network-layer Traffic Control Mechanisms
	See Also:		See Also:
	3.1.5 Flow		3.1.5 Flow
	Definition:		Definition:
	A flow is a one or more of packets sharing a common intended		A flow is a one or more of packets sharing a common intended
	pair of source and destination interfaces.		pair of source and destination interfaces.
	Discussion:		Discussion:
	skipping to change at page 7, line 47		skipping to change at page 8, line 4
	3.2.2 Conforming		3.2.2 Conforming
	Definition:		Definition:
	Packets which lie within specific rate, delay, or jitter		Packets which lie within specific rate, delay, or jitter
	bounds.		bounds.
	Discussion:		Discussion:
	A DUT/SUT may be configured to allow a given traffic class to		A DUT/SUT may be configured to allow a given traffic class to
	consume a given amount of bandwidth, or to fall within		consume a given amount of bandwidth, or to fall within
			Network-layer Traffic Control Mechanisms
	predefined delay or jitter boundaries. All packets that lie		predefined delay or jitter boundaries. All packets that lie
	within specified bounds are then said to be conforming,		within specified bounds are then said to be conforming,
	whereas those outside the bounds are nonconforming.		whereas those outside the bounds are nonconforming.
	Measurement units:		Measurement units:
	n/a		n/a
	See Also:		See Also:
	Expected Vector		Expected Vector
	Network-layer Traffic Control Mechanisms
	Forwarding Vector		Forwarding Vector
	Offered Vector		Offered Vector
	Nonconforming		Nonconforming
	3.2.3 Nonconforming		3.2.3 Nonconforming
	Definition:		Definition:
	Packets that do not lie within specific rate, delay, or		Packets that do not lie within specific rate, delay, or
	jitter bounds.		jitter bounds.
	skipping to change at page 8, line 47		skipping to change at page 9, line 5
	the last bit of the output IP packet is seen on the output		the last bit of the output IP packet is seen on the output
	port of the DUT/SUT.		port of the DUT/SUT.
	Discussion:		Discussion:
	Delay is measured the same regardless of the type of DUT/SUT.		Delay is measured the same regardless of the type of DUT/SUT.
	Latency [1] require some knowledge of whether the DUT/SUT is		Latency [1] require some knowledge of whether the DUT/SUT is
	a "store and forward" or a "bit forwarding" device. The fact		a "store and forward" or a "bit forwarding" device. The fact
	that a DUT/SUT's technology has a lower delay than another		that a DUT/SUT's technology has a lower delay than another
	technology should be visible.		technology should be visible.
			Network-layer Traffic Control Mechanisms
	By specifying the metric to be inside the Internet protocol,		By specifying the metric to be inside the Internet protocol,
	the tester is relieved from specifying the start/end for		the tester is relieved from specifying the start/end for
	every data link layer protocol that IP runs on. This avoids		every data link layer protocol that IP runs on. This avoids
	determining if the start/end delimiters are included in the		determining if the start/end delimiters are included in the
	frame. Also heterogeneous data link protocol can be used in		frame. Also heterogeneous data link protocol can be used in
	a test.		a test.
	The measurement point at the end closely simulates the way an		The measurement point at the end closely simulates the way an
	internet datagram is processed. An internet datagram is not		internet datagram is processed. An internet datagram is not
	Network-layer Traffic Control Mechanisms
	passed up or down the stack unless it is complete.		passed up or down the stack unless it is complete.
	Completion occurs once the last bit of the IP packet has been		Completion occurs once the last bit of the IP packet has been
	received.		received.
	Delay can be run at any offered load. Recommend at or below		Delay can be run at any offered load. Recommend at or below
	the channel capacity for non-congested delay. For congested		the channel capacity for non-congested delay. For congested
	delay, run the offered load above the channel capacity.		delay, run the offered load above the channel capacity.
	Measurement units:		Measurement units:
	Seconds.		Seconds.
	See Also:		See Also:
	Latency [1]		Latency [1]
			3.2.5 Jitter
			Definition:
			The absolute value of the difference between the arrival
			delay of two consecutive packets belonging to the same
			stream.
			Discussion:
			The delay fluctuation between two consecutive packets in a
			stream is reported as the jitter. Jitter can be expressed as
			|D(i) - D(i-1)| where D equals the delay and i is the test
			sequence number. The measurement does not include lost
			packets.
			Jitter can be determined by the ipdv [6] (IP Delay Variation)
			by taking the absolute value of the ipdv. The two metrics
			will produce different mean values. _Mean Jitter_ will
			produce a positive value, where the _mean ipdv_ is typically
			zero.
			Measurement units:
			Seconds
			See Also:
			Jitter variation [5]
			ipdv [6]
			interarrival jitter [7]
			Network-layer Traffic Control Mechanisms
	3.2.6 Undifferentiated Response		3.2.6 Undifferentiated Response
	Definition:		Definition:
	The vector(s) obtained when mechanisms used to support diff-		The vector(s) obtained when mechanisms used to support diff-
	serv or IP precedence are disabled.		serv or IP precedence are disabled.
	Discussion:		Discussion:
	Enabling diff-serv or IP precedence mechanisms may impose		Enabling diff-serv or IP precedence mechanisms may impose
	additional processing overhead for packets. This overhead may		additional processing overhead for packets. This overhead may
	degrade performance even when traffic belonging to only one		degrade performance even when traffic belonging to only one
	skipping to change at page 10, line 5		skipping to change at page 10, line 41
	Definition:		Definition:
	A received packet with the expected Test Sequence number.		A received packet with the expected Test Sequence number.
	Discussion:		Discussion:
	In-sequence is done on a stream level. As packets are		In-sequence is done on a stream level. As packets are
	received on a stream, each packet's Test Sequence number is		received on a stream, each packet's Test Sequence number is
	compared with the previous packet. Only packets that match		compared with the previous packet. Only packets that match
	the expected are considered in-sequence.		the expected are considered in-sequence.
	Network-layer Traffic Control Mechanisms
	Packets that do not match the expected Test Sequence number		Packets that do not match the expected Test Sequence number
	are counted as _not in-sequence_ or out-of-sequence. Every		are counted as _not in-sequence_ or out-of-sequence. Every
	packet that is received is either in-sequence or out-of-		packet that is received is either in-sequence or out-of-
	sequence. Subtracting the in-sequence from the received		sequence. Subtracting the in-sequence from the received
	packets (for that stream) can derive the out-of-sequence		packets (for that stream) can derive the out-of-sequence
	count.		count.
	Two types of events will prevent the in-sequence from		Two types of events will prevent the in-sequence from
	incrementing: packet loss and reordered packets.		incrementing: packet loss and reordered packets.
	Measurement units:		Measurement units:
	Packet count		Packet count
			Network-layer Traffic Control Mechanisms
	See Also:		See Also:
	Stream		Stream
	Test Sequence number		Test Sequence number
	3.3.2 Out-of-order Packet		3.3.2 Out-of-order Packet
	Definition:		Definition:
	A received packet with a Test Sequence number less that		A received packet with a Test Sequence number less that
	expected.		expected.
	skipping to change at page 11, line 4		skipping to change at page 11, line 43
	Packet loss does not affect the Out-of-order Packet count.		Packet loss does not affect the Out-of-order Packet count.
	Only packets that were not received in the order that they		Only packets that were not received in the order that they
	were transmitted.		were transmitted.
	Measurement units:		Measurement units:
	Packet count		Packet count
	See Also:		See Also:
	Stream		Stream
	Test Sequence number		Test Sequence number
	Network-layer Traffic Control Mechanisms
	3.3.3 Duplicate Packet		3.3.3 Duplicate Packet
	Definition:		Definition:
	A received packet with a Test Sequence number matching a		A received packet with a Test Sequence number matching a
	previously received packet.		previously received packet.
	Discussion:		Discussion:
	Measurement units:		Measurement units:
	Packet count		Packet count
			Network-layer Traffic Control Mechanisms
	See Also:		See Also:
	Stream		Stream
	Test Sequence number		Test Sequence number
	3.3.4 Stream		3.3.4 Stream
	Definition:		Definition:
	A group of packets tracked as a single entity by the traffic		A group of packets tracked as a single entity by the traffic
	receiver. A stream may share a common content such as type		receiver. A stream may share a common content such as type
	skipping to change at page 12, line 4		skipping to change at page 12, line 40
	a single entity. A mulitcast stream can be forward to		a single entity. A mulitcast stream can be forward to
	multiple destination interfaces.		multiple destination interfaces.
	Measurement units:		Measurement units:
	n/a		n/a
	See Also:		See Also:
	Flow		Flow
	MicroFlow [3]		MicroFlow [3]
	Test sequence number		Test sequence number
	Network-layer Traffic Control Mechanisms
	3.3.6 Test Sequence number		3.3.6 Test Sequence number
	Definition:		Definition:
	A field in the IP payload portion of the packet that is used		A field in the IP payload portion of the packet that is used
	to verify the order of the packets on the egress of the		to verify the order of the packets on the egress of the
	DUT/SUT.		DUT/SUT.
	Discussion:		Discussion:
	The traffic generator sets the test sequence number value and		The traffic generator sets the test sequence number value and
	the traffic receiver checks the value upon receipt of the		the traffic receiver checks the value upon receipt of the
	packet. The traffic generator changes the value on each		packet. The traffic generator changes the value on each
			Network-layer Traffic Control Mechanisms
	packet transmitted based on an algorithm agreed to by the		packet transmitted based on an algorithm agreed to by the
	traffic receiver.		traffic receiver.
	The traffic receiver keeps track of the sequence numbers on a		The traffic receiver keeps track of the sequence numbers on a
	per stream basis. In addition to number of received packets,		per stream basis. In addition to number of received packets,
	the traffic receiver may also report number of in-sequence		the traffic receiver may also report number of in-sequence
	packets, number of out-sequence packets, number of duplicate		packets, number of out-sequence packets, number of duplicate
	packets, and number of reordered packets.		packets, and number of reordered packets.
	The recommended algorithm to use to change the sequence		The recommended algorithm to use to change the sequence
	skipping to change at page 13, line 5		skipping to change at page 13, line 44
	A vector describing the rate at which packets having a		A vector describing the rate at which packets having a
	specific code-point (or IP precedence) that an external		specific code-point (or IP precedence) that an external
	source attempts to transmit to a DUT/SUT.		source attempts to transmit to a DUT/SUT.
	Discussion:		Discussion:
	Intended loads across the different code-point classes		Intended loads across the different code-point classes
	determine the metrics associated with a specific code-point		determine the metrics associated with a specific code-point
	traffic class.		traffic class.
	Network-layer Traffic Control Mechanisms
	Measurement Units:		Measurement Units:
	N-octets packets per second		N-octets packets per second
	See Also:		See Also:
	Offered Vector		Offered Vector
	Expected Forwarding Vector		Expected Forwarding Vector
	Expected Loss Vector		Expected Loss Vector
	Expected Sequence Vector		Expected Sequence Vector
	Expected Delay Vector		Expected Delay Vector
	Expected Jitter Vector		Expected Jitter Vector
	Forwarding Vector		Forwarding Vector
			Network-layer Traffic Control Mechanisms
	Loss Vector		Loss Vector
	3.4.2 Offered Vector		3.4.2 Offered Vector
	Definition:		Definition:
	A vector describing the measured rate at which packets having		A vector describing the measured rate at which packets having
	a specific DSCP or IP precedence value are offered to the		a specific DSCP or IP precedence value are offered to the
	DUT/SUT.		DUT/SUT.
	Discussion:		Discussion:
	skipping to change at page 14, line 4		skipping to change at page 14, line 43
	3.4.3.1 Expected Forwarding Vector		3.4.3.1 Expected Forwarding Vector
	Definition:		Definition:
	A vector describing the expected output rate of packets		A vector describing the expected output rate of packets
	having a specific DSCP or IP precedence value. The value is		having a specific DSCP or IP precedence value. The value is
	dependent on the set of offered vectors and configuration of		dependent on the set of offered vectors and configuration of
	the DUT.		the DUT.
	Discussion:		Discussion:
	Network-layer Traffic Control Mechanisms
	The DUT is configured in a certain way in order that service		The DUT is configured in a certain way in order that service
	differentiation occurs for a particular DSCP or IP precedence		differentiation occurs for a particular DSCP or IP precedence
	value when a specific traffic mix consisting of multiple		value when a specific traffic mix consisting of multiple
	DSCPs or IP precedence values are applied. This term attempts		DSCPs or IP precedence values are applied. This term attempts
	to capture the expected forwarding behavior when subjected to		to capture the expected forwarding behavior when subjected to
	a certain offered vectors.		a certain offered vectors.
	The actual algorithm or mechanism the DUT uses to achieve		The actual algorithm or mechanism the DUT uses to achieve
	service differentiation is not important in describing the		service differentiation is not important in describing the
	expected forwarding vector.		expected forwarding vector.
	Measurement units:		Measurement units:
	N-octet packets per second		N-octet packets per second
			Network-layer Traffic Control Mechanisms
	See Also:		See Also:
	Intended Vector		Intended Vector
	Offered Vector		Offered Vector
	Output Vectors		Output Vectors
	Expected Loss Vector		Expected Loss Vector
	Expected Sequence Vector		Expected Sequence Vector
	Expected Delay Vector		Expected Delay Vector
	Expected Jitter Vector		Expected Jitter Vector
	skipping to change at page 15, line 4		skipping to change at page 15, line 43
	expected loss vector.		expected loss vector.
	Measurement Units:		Measurement Units:
	Percentage of intended packets that are expected to be		Percentage of intended packets that are expected to be
	dropped.		dropped.
	See Also:		See Also:
	Intended Vector		Intended Vector
	Offered Vector		Offered Vector
	Expected Forwarding Vector		Expected Forwarding Vector
	Network-layer Traffic Control Mechanisms
	Expected Sequence Vector		Expected Sequence Vector
	Expected Delay Vector		Expected Delay Vector
	Expected Jitter Vector		Expected Jitter Vector
	3.2.3.3 Expected Sequence Vector		3.2.3.3 Expected Sequence Vector
	Definition:		Definition:
			Network-layer Traffic Control Mechanisms
	A vector describing the expected in-sequence packets having a		A vector describing the expected in-sequence packets having a
	specific DSCP or IP precedence value. The value is dependent		specific DSCP or IP precedence value. The value is dependent
	on the set of offered vectors and configuration of the DUT.		on the set of offered vectors and configuration of the DUT.
	Discussion:		Discussion:
	The DUT is configured in a certain way in order that service		The DUT is configured in a certain way in order that service
	differentiation occurs for a particular DSCP or IP precedence		differentiation occurs for a particular DSCP or IP precedence
	value when a specific traffic mix consisting of multiple		value when a specific traffic mix consisting of multiple
	DSCPs or IP precedence values are applied. This term attempts		DSCPs or IP precedence values are applied. This term attempts
	to capture the expected forwarding behavior when subjected to		to capture the expected forwarding behavior when subjected to
	skipping to change at page 16, line 5		skipping to change at page 16, line 50
	on the set of offered vectors and configuration of the DUT.		on the set of offered vectors and configuration of the DUT.
	Discussion:		Discussion:
	The DUT is configured in a certain way in order that service		The DUT is configured in a certain way in order that service
	differentiation occurs for a particular DSCP or IP precedence		differentiation occurs for a particular DSCP or IP precedence
	value when a specific traffic mix consisting of multiple		value when a specific traffic mix consisting of multiple
	DSCPs or IP precedence values are applied. This term attempts		DSCPs or IP precedence values are applied. This term attempts
	to capture the expected forwarding behavior when subjected to		to capture the expected forwarding behavior when subjected to
	a certain offered vectors.		a certain offered vectors.
	Network-layer Traffic Control Mechanisms
	The actual algorithm or mechanism the DUT uses to achieve		The actual algorithm or mechanism the DUT uses to achieve
	service differentiation is not important in describing the		service differentiation is not important in describing the
	expected delay vector.		expected delay vector.
	Measurement units:		Measurement units:
	Seconds.		Seconds.
	See Also:		See Also:
			Network-layer Traffic Control Mechanisms
	Intended Vector		Intended Vector
	Offered Vector		Offered Vector
	Output Vectors		Output Vectors
	Expected Loss Vector		Expected Loss Vector
	Expected Sequence Vector		Expected Sequence Vector
	Expected Forwarding Vector		Expected Forwarding Vector
	Expected Jitter Vector		Expected Jitter Vector
	3.4.3.5 Expected Average Delay Vector		3.4.3.5 Expected Average Delay Vector
	skipping to change at page 17, line 4		skipping to change at page 17, line 46
	Seconds.		Seconds.
	See Also:		See Also:
	Intended Vector		Intended Vector
	Offered Vector		Offered Vector
	Output Vectors		Output Vectors
	Expected Loss Vector		Expected Loss Vector
	Expected Sequence Vector		Expected Sequence Vector
	Expected Forwarding Vector		Expected Forwarding Vector
	Expected Jitter Vector		Expected Jitter Vector
	Network-layer Traffic Control Mechanisms
	3.4.3.6 Expected Maximum Delay Vector		3.4.3.6 Expected Maximum Delay Vector
	Definition:		Definition:
	A vector describing the expected maximum delay for packets		A vector describing the expected maximum delay for packets
	having a specific DSCP or IP precedence value. The value is		having a specific DSCP or IP precedence value. The value is
	dependent on the set of offered vectors and configuration of		dependent on the set of offered vectors and configuration of
	the DUT.		the DUT.
	Discussion:		Discussion:
	The DUT is configured in a certain way in order that service		The DUT is configured in a certain way in order that service
	differentiation occurs for a particular DSCP or IP precedence		differentiation occurs for a particular DSCP or IP precedence
			Network-layer Traffic Control Mechanisms
	value when a specific traffic mix consisting of multiple		value when a specific traffic mix consisting of multiple
	DSCPs or IP precedence values are applied. This term attempts		DSCPs or IP precedence values are applied. This term attempts
	to capture the expected forwarding behavior when subjected to		to capture the expected forwarding behavior when subjected to
	a certain offered vectors.		a certain offered vectors.
	The actual algorithm or mechanism the DUT uses to achieve		The actual algorithm or mechanism the DUT uses to achieve
	service differentiation is not important in describing the		service differentiation is not important in describing the
	expected maximum delay vector.		expected maximum delay vector.
	Measurement units:		Measurement units:
	skipping to change at page 18, line 5		skipping to change at page 18, line 47
	differentiation occurs for a particular DSCP or IP precedence		differentiation occurs for a particular DSCP or IP precedence
	value when a specific traffic mix consisting of multiple		value when a specific traffic mix consisting of multiple
	DSCPs or IP precedence values are applied. This term attempts		DSCPs or IP precedence values are applied. This term attempts
	to capture the expected forwarding behavior when subjected to		to capture the expected forwarding behavior when subjected to
	a certain offered vectors.		a certain offered vectors.
	The actual algorithm or mechanism the DUT uses to achieve		The actual algorithm or mechanism the DUT uses to achieve
	service differentiation is not important in describing the		service differentiation is not important in describing the
	expected minimum delay vector.		expected minimum delay vector.
	Network-layer Traffic Control Mechanisms
	Measurement units:		Measurement units:
	Seconds.		Seconds.
	See Also:		See Also:
	Intended Vector		Intended Vector
	Offered Vector		Offered Vector
	Output Vectors		Output Vectors
	Expected Loss Vector		Expected Loss Vector
	Expected Sequence Vector		Expected Sequence Vector
	Expected Forwarding Vector		Expected Forwarding Vector
			Network-layer Traffic Control Mechanisms
	Expected Jitter Vector		Expected Jitter Vector
	3.2.3.8 Expected Instantaneous Delay Variation Vector		3.2.3.8 Expected Instantaneous Jitter Vector
	Definition:		Definition:
	A vector describing the expected variation in the delay of		A vector describing the expected jitter between two
	two consecutive packets' arrival times having a specific DSCP		consecutive packets' arrival times having a specific DSCP or
	or IP precedence value. The value is dependent on the set of		IP precedence value. The value is dependent on the set of
	offered vectors and configuration of the DUT.		offered vectors and configuration of the DUT.
	Discussion:		Discussion:
	Instantaneous Delay Variation is the absolute value of the		Instantaneous Jitter is the absolute value of the difference
	difference between the delay measurement of two packets		between the delay measurement of two packets belonging to the
	belonging to the same stream.		same stream.
	The delay fluctuation between two consecutive packets in a		The delay fluctuation between two consecutive packets in a
	stream is reported as the "Instantaneous Delay Variation".		stream is reported as the "Instantaneous Jitter".
	Instantaneous Delay Variation can be expressed as |D(i) -		Instantaneous Jitter can be expressed as |D(i) - D(i-1)|
	D(i-1)| where D equals the delay and i is the test sequence		where D equals the delay and i is the test sequence number.
	number. Packets lost are not counted in the measurement.		Packets lost are not counted in the measurement.
	Forwarding Vector may contain several Instantaneous Delay		Forwarding Vector may contain several Jitter Vectors. For n
	Variation Vectors. For n packets received in a Forwarding		packets received in a Forwarding Vector, there is a total of
	Vector, there is n-1 several Instantaneous Delay Variation		(n-1) Instantaneous Jitter Vectors.
	Vectors.
	Measurement units:		Measurement units:
	Seconds		Seconds
	See Also:		See Also:
	Delay		Delay
			Jitter
	Offered Vector		Offered Vector
	Output Vectors		Output Vectors
	Expected Average Delay Variation Vector		Expected Average Jitter Vector
	Expected Peak-to-peak Delay Variation Vector		Expected Peak-to-peak Jitter Vector
	Stream		Stream
	Network-layer Traffic Control Mechanisms
	3.2.3.9 Expected Average Delay Variation Vector		3.2.3.9 Expected Average Jitter Vector
	Definition:		Definition:
	A vector describing the expected average variation in the		A vector describing the expected jitter in packet arrival
	delay of packet arrival times for packets having specific		times for packets having specific DSCP or IP precedence
	DSCP or IP precedence value. The value is dependent on the		value. The value is dependent on the set of offered vectors
	set of offered vectors and configuration of the DUT.		and configuration of the DUT.
	Discussion:		Discussion:
	Average Delay Variation is the average of all the		Average Jitter Vector is the average of all the Instantaneous
	Instantaneous Delay Variation Vectors measured during the		Jitter Vectors measured during the test duration for the same
	test duration.		DSCP or IP precedence value.
			Network-layer Traffic Control Mechanisms
	Measurement units:		Measurement units:
	Seconds		Seconds
	See Also:		See Also:
	Intended Vector		Intended Vector
	Offered Vector		Offered Vector
	Output Vectors		Output Vectors
	Expected Instantaneous Delay Variation Vector		Expected Instantaneous Jitter Vector
	Expected Peak-to-peak Delay Variation Vector		Expected Peak-to-peak Jitter Vector
	3.2.3.10 Expected Peak-to-peak Delay Variation Vector		3.2.3.10 Expected Peak-to-peak Jitter Vector
	Definition:		Definition:
	A vector describing the expected maximum variation in the		A vector describing the expected maximum variation in the
	delay of packet arrival times for packets having specific		delay of packet arrival times for packets having specific
	DSCP or IP precedence value. The value is dependent on the		DSCP or IP precedence value. The value is dependent on the
	set of offered vectors and configuration of the DUT.		set of offered vectors and configuration of the DUT.
	Discussion:		Discussion:
	Peak-to-peak Delay Variation Vector is the maximum delay		Peak-to-peak Jitter Vector is the maximum delay minus the
	minus the minimum delay of the packets (in a vector)		minimum delay of the packets (in a vector) forwarded by the
	forwarded by the DUT/SUT.		DUT/SUT.
	Peak-to-peak Delay Variation is not derived from the		Peak-to-peak Jitter is not derived from the Instantaneous
	Instantaneous Delay Variation Vector. Peak-to-peak Delay		Jitter Vector. Peak-to-peak Jitter is based upon all the
	Variation is based upon all the packets during the test		packets during the test duration, not just two consecutive
	duration, not just two consecutive packets.		packets.
	Measurement units:		Measurement units:
	Seconds		Seconds
	See Also:		See Also:
	Intended Vector		Intended Vector
	Offered Vector		Offered Vector
	Output Vectors		Output Vectors
	Expected Instantaneous Delay Variation Vector		Expected Instantaneous Jitter Vector
	Expected Average Delay Variation Vector		Expected Average Jitter Vector
	Network-layer Traffic Control Mechanisms
	3.4.4 Output Vectors		3.4.4 Output Vectors
	3.4.4.1 Forwarding Vector		3.4.4.1 Forwarding Vector
			Network-layer Traffic Control Mechanisms
	Definition:		Definition:
	The number of packets per second for all packets containing a		The number of packets per second for all packets containing a
	specific DSCP or IP precedence value that a device can be		specific DSCP or IP precedence value that a device can be
	observed to successfully forward to the correct destination		observed to successfully forward to the correct destination
	interface in response to an offered vector.		interface in response to an offered vector.
	Discussion:		Discussion:
	Forwarding Vector is expressed as pair of numbers. Both the		Forwarding Vector is expressed as pair of numbers. Both the
	specific DSCP (or IP precedence) value AND the packets per		specific DSCP (or IP precedence) value AND the packets per
	skipping to change at page 21, line 5		skipping to change at page 21, line 51
	The percentage of packets containing specific DSCP or IP		The percentage of packets containing specific DSCP or IP
	precedence value that a DUT/SUT did not transmit to the		precedence value that a DUT/SUT did not transmit to the
	correct destination interface in response to an offered		correct destination interface in response to an offered
	vector.		vector.
	Discussion:		Discussion:
	Loss Vector is expressed as pair of numbers. Both the		Loss Vector is expressed as pair of numbers. Both the
	specific DSCP (or IP precedence) value AND the percentage		specific DSCP (or IP precedence) value AND the percentage
	value combine to make a vector.		value combine to make a vector.
	Network-layer Traffic Control Mechanisms
	The Loss Vector represents percentage based on a specific		The Loss Vector represents percentage based on a specific
	DSCP or IP precedence value. It is not necessarily based on		DSCP or IP precedence value. It is not necessarily based on
	a stream or flow. The Loss Vector may be expressed as per		a stream or flow. The Loss Vector may be expressed as per
	port of the DUT/SUT. However, it must be consistent with the		port of the DUT/SUT. However, it must be consistent with the
	Expected Loss Vector		Expected Loss Vector
			Network-layer Traffic Control Mechanisms
	Loss Vector is a per-hop measurement. The DUT/SUT may change		Loss Vector is a per-hop measurement. The DUT/SUT may change
	the specific DSCP or IP precedence value for a multiple-hop		the specific DSCP or IP precedence value for a multiple-hop
	measurement.		measurement.
	Measurement Units:		Measurement Units:
	Percentage of offered packets that are not forwarded.		Percentage of offered packets that are not forwarded.
	See Also:		See Also:
	Intended Vector		Intended Vector
	skipping to change at page 22, line 4		skipping to change at page 22, line 51
	change the specific DSCP or IP precedence value for a		change the specific DSCP or IP precedence value for a
	multiple-hop measurement.		multiple-hop measurement.
	Measurement Units:		Measurement Units:
	N-octet packets per second		N-octet packets per second
	Issues:		Issues:
	See Also:		See Also:
	In-sequence Packet		In-sequence Packet
	Network-layer Traffic Control Mechanisms
	Intended Vector		Intended Vector
	Offered Vector		Offered Vector
	Expected Vectors		Expected Vectors
	Loss Vector		Loss Vector
	Forwarding Vector		Forwarding Vector
			Network-layer Traffic Control Mechanisms
	Delay Vectors		Delay Vectors
	3.4.4.4 Instantaneous Delay Vector		3.4.4.4 Instantaneous Delay Vector
	Definition:		Definition:
	The delay for a packet containing specific DSCP or IP		The delay for a packet containing specific DSCP or IP
	precedence value that a device can be observed to		precedence value that a device can be observed to
	successfully transmit to the correct destination interface in		successfully transmit to the correct destination interface in
	response to an offered vector.		response to an offered vector.
	skipping to change at page 23, line 4		skipping to change at page 23, line 51
	Seconds		Seconds
	See Also:		See Also:
	Delay		Delay
	Intended Vector		Intended Vector
	Offered Vector		Offered Vector
	Expected Delay Vectors		Expected Delay Vectors
	Average Delay Vector		Average Delay Vector
	Maximum Delay Vector		Maximum Delay Vector
	Minimum Delay Vector		Minimum Delay Vector
	Network-layer Traffic Control Mechanisms
	3.4.4.5 Average Delay Vector		3.4.4.5 Average Delay Vector
	Definition:		Definition:
			Network-layer Traffic Control Mechanisms
	The average delay for packets containing specific DSCP or IP		The average delay for packets containing specific DSCP or IP
	precedence value that a device can be observed to		precedence value that a device can be observed to
	successfully transmit to the correct destination interface in		successfully transmit to the correct destination interface in
	response to an offered vector.		response to an offered vector.
	Discussion:		Discussion:
	Average Delay vector is expressed as pair of numbers. Both		Average Delay vector is expressed as pair of numbers. Both
	the specific DSCP (or IP precedence) value AND delay value		the specific DSCP (or IP precedence) value AND delay value
	combine to make a vector.		combine to make a vector.
	skipping to change at page 24, line 5		skipping to change at page 24, line 55
	Minimum Delay Vector		Minimum Delay Vector
	3.4.4.6 Maximum Delay Vector		3.4.4.6 Maximum Delay Vector
	Definition:		Definition:
	The maximum delay from all packets containing specific DSCP		The maximum delay from all packets containing specific DSCP
	or IP precedence value that a device can be observed to		or IP precedence value that a device can be observed to
	successfully transmit to the correct destination interface in		successfully transmit to the correct destination interface in
	response to an offered vector.		response to an offered vector.
			Discussion:
	Network-layer Traffic Control Mechanisms		Network-layer Traffic Control Mechanisms
	Discussion:
	Maximum Delay vector is expressed as pair of numbers. Both		Maximum Delay vector is expressed as pair of numbers. Both
	the specific DSCP (or IP precedence) value AND delay value		the specific DSCP (or IP precedence) value AND delay value
	combine to make a vector.		combine to make a vector.
	The Maximum Delay Vector represents delay on its specific		The Maximum Delay Vector represents delay on its specific
	DSCP or IP precedence value. It is not necessarily based on		DSCP or IP precedence value. It is not necessarily based on
	a stream or flow. The Maximum Delay vector may be expressed		a stream or flow. The Maximum Delay vector may be expressed
	as per port of the DUT/SUT. However, it must be consistent		as per port of the DUT/SUT. However, it must be consistent
	with the Expected Delay vector.		with the Expected Delay vector.
	skipping to change at page 25, line 5		skipping to change at page 25, line 56
	Delay vector is expressed as pair of numbers. Both the		Delay vector is expressed as pair of numbers. Both the
	specific DSCP (or IP precedence) value AND delay value		specific DSCP (or IP precedence) value AND delay value
	combine to make a vector.		combine to make a vector.
	The Minimum Delay Vector represents delay on its specific		The Minimum Delay Vector represents delay on its specific
	DSCP or IP precedence value. It is not necessarily based on		DSCP or IP precedence value. It is not necessarily based on
	a stream or flow. The Minimum Delay vector may be expressed		a stream or flow. The Minimum Delay vector may be expressed
	as per port of the DUT/SUT. However, it must be consistent		as per port of the DUT/SUT. However, it must be consistent
	with the Expected Delay vector.		with the Expected Delay vector.
	Network-layer Traffic Control Mechanisms
	Minimum Delay Vector is based upon the minimum Instantaneous		Minimum Delay Vector is based upon the minimum Instantaneous
	Delay Vector of all packets in a Forwarding Vector.		Delay Vector of all packets in a Forwarding Vector.
			Network-layer Traffic Control Mechanisms
	Minimum Delay Vector is a per-hop measurement. The DUT/SUT		Minimum Delay Vector is a per-hop measurement. The DUT/SUT
	may change the specific DSCP or IP precedence value for a		may change the specific DSCP or IP precedence value for a
	multiple-hop measurement.		multiple-hop measurement.
	Minimum Delay vector can be obtained at any offered load.		Minimum Delay vector can be obtained at any offered load.
	Recommend at or below the channel capacity in the absence of		Recommend at or below the channel capacity in the absence of
	congestion. For congested delay, run the offered load above		congestion. For congested delay, run the offered load above
	the channel capacity.		the channel capacity.
	Measurement Units:		Measurement Units:
	skipping to change at page 25, line 32		skipping to change at page 26, line 29
	See Also:		See Also:
	Delay		Delay
	Intended Vector		Intended Vector
	Offered Vector		Offered Vector
	Expected Delay Vectors		Expected Delay Vectors
	Instantaneous Delay Vector		Instantaneous Delay Vector
	Forwarding Vector		Forwarding Vector
	Average Delay Vector		Average Delay Vector
	Maximum Delay Vector		Maximum Delay Vector
	3.4.4.8 Instantaneous Delay Variation Vector		3.4.4.8 Instantaneous Jitter Vector
	Definition:		Definition:
	The variation in the delay for two consecutive packets		The jitter for two consecutive packets containing specific
	containing specific DSCP or IP precedence value that a device		DSCP or IP precedence value that a device can be observed to
	can be observed to successfully transmit to the correct		successfully transmit to the correct destination interface in
	destination interface in response to an offered vector.		response to an offered vector.
	Discussion:		Discussion:
	Instantaneous Delay Variation is the absolute value of the		Instantaneous Jitter is the absolute value of the difference
	difference between the delay measurement of two packets		between the delay measurement of two packets belonging to the
	belonging to the same stream.		same stream.
	Jitter vector is expressed as pair of numbers. Both the		Jitter vector is expressed as pair of numbers. Both the
	specific DSCP (or IP precedence) value AND jitter value		specific DSCP (or IP precedence) value AND jitter value
	combine to make a vector.		combine to make a vector.
	The delay fluctuation between two consecutive packets in a		The delay fluctuation between two consecutive packets in a
	stream is reported as the "Instantaneous Delay Variation".		stream is reported as the "Instantaneous Jitter".
	Instantaneous Delay Variation can be expressed as |D(i) -		Instantaneous Jitter Vector can be expressed as |D(i) - D(i-
	D(i-1)| where D equals the delay and i is the test sequence		1)| where D equals the delay and i is the test sequence
	number. Packets lost are not counted in the measurement.		number. Packets lost are not counted in the measurement.
	Network-layer Traffic Control Mechanisms		Instantaneous Jitter Vector is a per-hop measurement. The
			DUT/SUT may change the specific DSCP or IP precedence value
			for a multiple-hop measurement.
	Instantaneous Delay Variation Vector is a per-hop		Network-layer Traffic Control Mechanisms
	measurement. The DUT/SUT may change the specific DSCP or IP
	precedence value for a multiple-hop measurement.
	Forwarding Vector may contain several Instantaneous Delay		Forwarding Vector may contain several Instantaneous Jitter
	Variation Vectors. For n packets received in a Forwarding		Vectors. For n packets received in a Forwarding Vector,
	Vector, there is n-1 several Instantaneous Delay Variation		there are exactly (n-1) Instantaneous Jitter Vectors.
	Vectors.
	Measurement units:		Measurement units:
	Seconds		Seconds
	See Also:		See Also:
	Delay		Delay
			Jitter
	Forwarding Vector		Forwarding Vector
	Stream		Stream
	Expected Vectors		Expected Vectors
	Average Delay Variation Vector		Average Jitter Vector
	Peak-to-peak Delay Variation Vector		Peak-to-peak Jitter Vector
	3.4.4.9 Average Delay Variation Vector		3.4.4.9 Average Jitter Vector
	Definition:		Definition:
	The average variation in the delay for packets containing		The average jitter for packets containing specific DSCP or IP
	specific DSCP or IP precedence value that a device can be		precedence value that a device can be observed to
	observed to successfully transmit to the correct destination		successfully transmit to the correct destination interface in
	interface in response to an offered vector.		response to an offered vector.
	Discussion:		Discussion:
	Average Delay Variation is the average of all the		Average Jitter Vector is the average of all the Instantaneous
	Instantaneous Delay Variation Vectors measured during the		Jitter Vectors of the same DSCP or IP precedence value,
	test duration.		measured during the test duration.
	Average Delay Variation vector is expressed as pair of		Average Jitter vector is expressed as pair of numbers. Both
	numbers. Both the specific DSCP (or IP precedence) value AND		the specific DSCP (or IP precedence) value AND jitter value
	jitter value combine to make a vector.		combine to make a vector.
	Average Delay Variation vector is a per-hop measurement. The		Average Jitter vector is a per-hop measurement. The DUT/SUT
	DUT/SUT may change the specific DSCP or IP precedence value		may change the specific DSCP or IP precedence value for a
	for a multiple-hop measurement.		multiple-hop measurement.
	Measurement units:		Measurement units:
	Seconds		Seconds
	See Also:		See Also:
	Delay		Jitter
	Forwarding Vector		Forwarding Vector
	Stream		Stream
	Expected Vectors		Expected Vectors
	Instantaneous Delay Variation Vector		Instantaneous Jitter Vector
	Peak-to-peak Delay Variation Vector		Peak-to-peak Jitter Vector
	Network-layer Traffic Control Mechanisms
	3.4.4.10 Peak-to-peak Delay Variation Vector		3.4.4.10 Peak-to-peak Jitter Vector
			Network-layer Traffic Control Mechanisms
	Definition:		Definition:
	The maximum possible variation in the delay for packets		The maximum possible variation in the delay for packets
	containing specific DSCP or IP precedence value that a device		containing specific DSCP or IP precedence value that a device
	can be observed to successfully transmit to the correct		can be observed to successfully transmit to the correct
	destination interface in response to an offered vector.		destination interface in response to an offered vector.
	Discussion:		Discussion:
	Peak-to-peak Delay Variation Vector is the maximum delay		Peak-to-peak Jitter Vector is the maximum delay minus the
	minus the minimum delay of the packets (in a vector)		minimum delay of the packets (in a vector) forwarded by the
	forwarded by the DUT/SUT.		DUT/SUT.
	Delay Variation vector is expressed as pair of numbers. Both		Jitter vector is expressed as pair of numbers. Both the
	the specific DSCP (or IP precedence) value AND jitter value		specific DSCP (or IP precedence) value AND jitter value
	combine to make a vector.		combine to make a vector.
	Peak-to-peak Delay Variation is not derived from the		Peak-to-peak Jitter is not derived from the Instantaneous
	Instantaneous Delay Variation Vector. Peak-to-peak Delay		Jitter Vector. Peak-to-peak Jitter is based upon all the
	Variation is based upon all the packets during the test		packets during the test duration, not just two consecutive
	duration, not just two consecutive packets.		packets.
	Measurement units:		Measurement units:
	Seconds		Seconds
	See Also:		See Also:
	Delay		Jitter
	Forwarding Vector		Forwarding Vector
	Stream		Stream
	Expected Vectors		Expected Vectors
	Average Delay Variation Vector		Average Jitter Vector
	Peak-to-peak Delay Variation Vector		Peak-to-peak Jitter Vector
	Network-layer Traffic Control Mechanisms		Network-layer Traffic Control Mechanisms
	4. Security Considerations		4. Security Considerations
	Documents of this type do not directly affect the security of		Documents of this type do not directly affect the security of
	the Internet or of corporate networks as long as benchmarking		the Internet or of corporate networks as long as benchmarking
	is not performed on devices or systems connected to		is not performed on devices or systems connected to
	production networks.		production networks.
	Packets with unintended and/or unauthorized DSCP or IP		Packets with unintended and/or unauthorized DSCP or IP
	skipping to change at page 29, line 5		skipping to change at page 29, line 34
	Switching Devices", RFC 2285, February 1998.		Switching Devices", RFC 2285, February 1998.
	[3] K. Nichols, S. Blake, F. Baker, D. Black,"Definition of		[3] K. Nichols, S. Blake, F. Baker, D. Black,"Definition of
	the Differentiated Services Field (DS Field) in the IPv4		the Differentiated Services Field (DS Field) in the IPv4
	and IPv6 Headers", RFC 2474, December 1998.		and IPv6 Headers", RFC 2474, December 1998.
	[4] S. Blake, D. Black, M. Carlson, E. Davies, Z. Wang, W.		[4] S. Blake, D. Black, M. Carlson, E. Davies, Z. Wang, W.
	Weiss, "An Architecture for Differentiated Services", RFC		Weiss, "An Architecture for Differentiated Services", RFC
	2475, December 1998.		2475, December 1998.
			[5] V. Jacobson, K. Nichols, K. Poduri, _An Expedited
			Forwarding PHB_, RFC 2598, June 1999
			[6] C. Demichelis, P. Chimento, _IP Packet Delay Variation
			Metric for IPPM_, draft-ietf-ippm-ipdv-10.txt
			[7] H. Schulzrinne, GMD Fokus, S. Casner, R. Frederick,
			V. Jacobson, _RTP: A Transport Protocol for Real-Time
			Applications_, RFC 1889, January 1996
			[8] A. Mankin, K. Ramakrishnan, _Gateway Congestion Control
			Survey_, RFC 1254, August 1991
	Network-layer Traffic Control Mechanisms		Network-layer Traffic Control Mechanisms
	6. Authors' Address		6. Authors' Address
	Jerry Perser		Jerry Perser
	Spirent Communications		Spirent Communications
	26750 Agoura Road		26750 Agoura Road
	Calabasas, CA 91302		Calabasas, CA 91302
	USA		USA
End of changes.
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