< draft-dreibholz-ipv4-flowlabel-34.txt		draft-dreibholz-ipv4-flowlabel-35.txt >
	Network Working Group T. Dreibholz		Network Working Group T. Dreibholz
	Internet-Draft SimulaMet		Internet-Draft SimulaMet
	Intended status: Standards Track September 06, 2021		Intended status: Standards Track 21 March 2022
	Expires: March 10, 2022		Expires: 22 September 2022
	An IPv4 Flowlabel Option		An IPv4 Flowlabel Option
	draft-dreibholz-ipv4-flowlabel-34		draft-dreibholz-ipv4-flowlabel-35
	Abstract		Abstract
	This draft defines an IPv4 option containing a flowlabel that is		This draft defines an IPv4 option containing a flowlabel that is
	compatible to IPv6. It is required for simplified usage of IntServ		compatible to IPv6. It is required for simplified usage of IntServ
	and interoperability with IPv6.		and interoperability with IPv6.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	skipping to change at page 1, line 32 ¶		skipping to change at page 1, line 32 ¶
	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 https://datatracker.ietf.org/drafts/current/.		Drafts is at https://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 March 10, 2022.		This Internet-Draft will expire on 22 September 2022.
	Copyright Notice		Copyright Notice
	Copyright (c) 2021 IETF Trust and the persons identified as the		Copyright (c) 2022 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
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	publication of this document. Please review these documents		Please review these documents carefully, as they describe your rights
	carefully, as they describe your rights and restrictions with respect		and restrictions with respect to this document. Code Components
	to this document. Code Components extracted from this document must		extracted from this document must include Revised BSD License text as
	include Simplified BSD License text as described in Section 4.e of		described in Section 4.e of the Trust Legal Provisions and are
	the Trust Legal Provisions and are provided without warranty as		provided without warranty as described in the Revised BSD License.
	described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2		1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2
	1.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 2		1.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 2
	1.3. Conventions . . . . . . . . . . . . . . . . . . . . . . . 3		1.3. Conventions . . . . . . . . . . . . . . . . . . . . . . . 3
	2. A Flow Label Option for IPv4 . . . . . . . . . . . . . . . . 3		2. A Flow Label Option for IPv4 . . . . . . . . . . . . . . . . 3
	2.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . 3		2.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . 3
	2.1.1. The Flow Label Field of IPv6 . . . . . . . . . . . . 3		2.1.1. The Flow Label Field of IPv6 . . . . . . . . . . . . 3
	2.1.2. The Limitations of IntServ via IPv4 . . . . . . . . . 4		2.1.2. The Limitations of IntServ via IPv4 . . . . . . . . . 4
	2.2. Definition of the Flow Label Option . . . . . . . . . . . 5		2.2. Definition of the Flow Label Option . . . . . . . . . . . 5
	3. Translation between IPv6 and IPv4 . . . . . . . . . . . . . . 6		3. Translation between IPv6 and IPv4 . . . . . . . . . . . . . . 6
	4. Security Considerations . . . . . . . . . . . . . . . . . . . 6		4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
	5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6		5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
	6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6		6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6
	7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6		7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
	7.1. Normative References . . . . . . . . . . . . . . . . . . 7		7.1. Normative References . . . . . . . . . . . . . . . . . . 6
	7.2. Informative References . . . . . . . . . . . . . . . . . 7		7.2. Informative References . . . . . . . . . . . . . . . . . 7
	Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8		Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8
	1. Introduction		1. Introduction
	1.1. Terminology		1.1. Terminology
	This document uses the following terms:		This document uses the following terms:
	o IntServ (Integrated Services): Reservation of network resources		* IntServ (Integrated Services): Reservation of network resources
	(bandwidth) on a per-flow basis. See [RFC1633], [RFC2205],		(bandwidth) on a per-flow basis. See [RFC1633], [RFC2205],
	[RFC2208], [RFC2209], [RFC2210], [RFC2211] and [RFC2212] for		[RFC2208], [RFC2209], [RFC2210], [RFC2211] and [RFC2212] for
	details.		details.
	o Flow: An IntServ reservation between two endpoints.		* Flow: An IntServ reservation between two endpoints.
	o Flow Label: The Flow Label field of the IPv6 header and the IPv4		* Flow Label: The Flow Label field of the IPv6 header and the IPv4
	option header defined in this draft. It is used for marking a		option header defined in this draft. It is used for marking a
	packet to use a specific IntServ reservation. See [RFC6437],		packet to use a specific IntServ reservation. See [RFC6437],
	[RFC6436] for detailed descriptions.		[RFC6436] for detailed descriptions.
	1.2. Abbreviations		1.2. Abbreviations
	o RSVP: ReSource Reservation Protocol		* RSVP: ReSource Reservation Protocol
	o SCTP: Stream Control Transmission Protocol		* SCTP: Stream Control Transmission Protocol
	o TCP: Transmission Control Protocol		* TCP: Transmission Control Protocol
	o QoS: Quality of Service		* QoS: Quality of Service
	o UDP: User Datagram Protocol		* UDP: User Datagram Protocol
	1.3. Conventions		1.3. Conventions
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and		"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
	"OPTIONAL" in this document are to be interpreted as described in BCP		"OPTIONAL" in this document are to be interpreted as described in BCP
	14 [RFC2119] [RFC8174] when, and only when, they appear in all		14 [RFC2119] [RFC8174] when, and only when, they appear in all
	capitals, as shown here.		capitals, as shown here.
	2. A Flow Label Option for IPv4		2. A Flow Label Option for IPv4
	skipping to change at page 3, line 38 ¶		skipping to change at page 3, line 38 ¶
	idea behind the flow label is marking specific flows for IntServ.		idea behind the flow label is marking specific flows for IntServ.
	That is, the routers on the path from source to destination keep e.g.		That is, the routers on the path from source to destination keep e.g.
	reservation states for the flows. The flow label provides easy		reservation states for the flows. The flow label provides easy
	identification and utilizes efficient lookup, e.g. using a hash		identification and utilizes efficient lookup, e.g. using a hash
	function on the 3-tuple (source address, destination address, flow		function on the 3-tuple (source address, destination address, flow
	label).		label).
	Using the IPv6 flow label, packets can be mapped easily to specific		Using the IPv6 flow label, packets can be mapped easily to specific
	flows, with the following features:		flows, with the following features:
	o Transport Layer Protocol Independence: Since the mapping is		* Transport Layer Protocol Independence: Since the mapping is
	directly specified in the IP header, all possible layer 4		directly specified in the IP header, all possible layer 4
	protocols are supported, even protocols to be specified in a far		protocols are supported, even protocols to be specified in a far
	future.		future.
	o Support for Network Layer Encryption: The mapping is independent		* Support for Network Layer Encryption: The mapping is independent
	of payload encryption (e.g. by IPsec).		of payload encryption (e.g. by IPsec).
	o Support for Fragmentation: If fragmentation of a large IP packet		* Support for Fragmentation: If fragmentation of a large IP packet
	is necessary, all fragments contain the same flow label.		is necessary, all fragments contain the same flow label.
	Therefore, fragmentation does not cause any flow-marking problem.		Therefore, fragmentation does not cause any flow-marking problem.
	o Flow Sharing: By marking packets with a flow label, it is possible		* Flow Sharing: By marking packets with a flow label, it is possible
	to share a single flow (IntServ reservation) with several		to share a single flow (IntServ reservation) with several
	communication associations from host A to host B. For example, a		communication associations from host A to host B. For example, a
	video stream via UDP and a HTTP download via TCP could share a		video stream via UDP and a HTTP download via TCP could share a
	single reservation. For the user, flow sharing has the advantage		single reservation. For the user, flow sharing has the advantage
	that if one of its communication associations temporarily requires		that if one of its communication associations temporarily requires
	lower bandwidth than expected, other associations sharing the same		lower bandwidth than expected, other associations sharing the same
	flow may use the remaining bandwidth. That is, his possibly		flow may use the remaining bandwidth. That is, his possibly
	expensive reservation is fully utilized. Flow sharing also helps		expensive reservation is fully utilized. Flow sharing also helps
	keeping the total number of reservations a router has to handle		keeping the total number of reservations a router has to handle
	small, reducing their CPU and memory requirements and therefore		small, reducing their CPU and memory requirements and therefore
	cost.		cost.
	o Multi-Flow Connections: One communication association can divide		* Multi-Flow Connections: One communication association can divide
	up its packets to several flows, simply by marking packets with		up its packets to several flows, simply by marking packets with
	different flow labels. This technique can be used for layered		different flow labels. This technique can be used for layered
	transmission. That is, a stream (e.g. a video) is divided up into		transmission. That is, a stream (e.g. a video) is divided up into
	several parts (called layers). For example, the first layer (base		several parts (called layers). For example, the first layer (base
	layer) of a video contains a low-quality version, the second (1st		layer) of a video contains a low-quality version, the second (1st
	enhancement layer) the data to generate a higher-quality version,		enhancement layer) the data to generate a higher-quality version,
	etc.. Now, the first layer can be mapped to a high-quality		etc.. Now, the first layer can be mapped to a high-quality
	reservation (guaranteed bandwidth, low loss rate) at higher cost,		reservation (guaranteed bandwidth, low loss rate) at higher cost,
	but the following layers can be mapped to lower-quality		but the following layers can be mapped to lower-quality
	reservations (e.g. higher loss rate) or even best effort at lower		reservations (e.g. higher loss rate) or even best effort at lower
	cost. Research shows that the total transmission cost can be		cost. Research shows that the total transmission cost can be
	highly reduced using layered transmission (see [Dre2001],		highly reduced using layered transmission (see [Dre2001],
	[IJMUE2009] for details).		[IJMUE2009] for details).
	2.1.2. The Limitations of IntServ via IPv4		2.1.2. The Limitations of IntServ via IPv4
	Using IntServ with IPv4, there are several problems that can only be		Using IntServ with IPv4, there are several problems that can only be
	solved with high management effort:		solved with high management effort:
	o No Transport Layer Protocol Independence: It is necessary to mark		* No Transport Layer Protocol Independence: It is necessary to mark
	the packets within the layer 4 protocol header. For example, the		the packets within the layer 4 protocol header. For example, the
	TCP, UDP or SCTP port numbers can be used to mark flows (with		TCP, UDP or SCTP port numbers can be used to mark flows (with
	limitations, see below). But for new protocols (e.g.		limitations, see below). But for new protocols (e.g.
	experimental, new standards, proprietary), software updates for		experimental, new standards, proprietary), software updates for
	*all* IntServ routers are necessary to recognize the packet flow!		*all* IntServ routers are necessary to recognize the packet flow!
	o No Support for Network Layer Encryption: Since it is necessary to		* No Support for Network Layer Encryption: Since it is necessary to
	read fields of the layer 4 protocol header, it may not be		read fields of the layer 4 protocol header, it may not be
	encrypted. Therefore, e.g. the usage of IPsec is impossible.		encrypted. Therefore, e.g. the usage of IPsec is impossible.
	o Support for Fragmentation: Only the first fragment of a large		* Support for Fragmentation: Only the first fragment of a large
	packet contains the layer 4 header necessary to map the packet to		packet contains the layer 4 header necessary to map the packet to
	a flow. Mapping other fragments would require the hops to		a flow. Mapping other fragments would require the hops to
	remember packet identities and try to map fragments to packet		remember packet identities and try to map fragments to packet
	identities. Due to the management effort and memory requirements,		identities. Due to the management effort and memory requirements,
	this is not realistic for high-bandwidth backbone routers;		this is not realistic for high-bandwidth backbone routers;
	especially when packet reordering must be considered.		especially when packet reordering must be considered.
	Furthermore, load sharing or traffic distribution would be		Furthermore, load sharing or traffic distribution would be
	impossible.		impossible.
	o No Flow Sharing: It is usually impossible for two different		* No Flow Sharing: It is usually impossible for two different
	communication associations to share the same flow, e.g. if TCP		communication associations to share the same flow, e.g. if TCP
	flows are recognized using port numbers. This makes it necessary		flows are recognized using port numbers. This makes it necessary
	to reserve an IntServ flow for each communication association.		to reserve an IntServ flow for each communication association.
	This implies an increased number of flow states for routers to		This implies an increased number of flow states for routers to
	keep and maintain. Furthermore, if one association temporarily		keep and maintain. Furthermore, if one association temporarily
	uses a lower bandwidth, the free bandwidth of its flow cannot		uses a lower bandwidth, the free bandwidth of its flow cannot
	easily be borrowed to another association.		easily be borrowed to another association.
	o No Multi-Flow Connections: To use layered transmission, e.g. a		* No Multi-Flow Connections: To use layered transmission, e.g. a
	video via UDP, the transmission of every layer would require own		video via UDP, the transmission of every layer would require own
	port numbers. In the case of connection-oriented transmission		port numbers. In the case of connection-oriented transmission
	protocols (e.g. TCP, SCTP), every layer would even require its		protocols (e.g. TCP, SCTP), every layer would even require its
	own connection setup and management. Depending on the transport		own connection setup and management. Depending on the transport
	protocol, the number of communication associations and the number		protocol, the number of communication associations and the number
	of flows, much more work is necessary compared to IPv6 using flow		of flows, much more work is necessary compared to IPv6 using flow
	labels.		labels.
	All in all, using IntServ flows with IPv4 requires much more work		All in all, using IntServ flows with IPv4 requires much more work
	compared to IPv6, where simply the flow label can be used. It is		compared to IPv6, where simply the flow label can be used. It is
	skipping to change at page 5, line 49 ¶		skipping to change at page 5, line 51 ¶
	Flow Label Option		Flow Label Option
	0 1 2 3		0 1 2 3
	0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1		0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Type | Length |0 0 0 0 0 0 0 0|0 0 0 0 0 0 0 0|		| Type | Length |0 0 0 0 0 0 0 0|0 0 0 0 0 0 0 0|
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	|0 0 0 0 0 0 0 0|0 0 0 0| Flow Label |		|0 0 0 0 0 0 0 0|0 0 0 0| Flow Label |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	o Type: 143		* Type: 143
			* Length: 8 octets
	o Length: 8 octets		* Flow Label: The 20-bit flow label. All definitions of [RFC6437]
	o Flow Label: The 20-bit flow label. All definitions of [RFC6437]
	and [RFC6436] for the IPv6 flow label are also valid for this		and [RFC6436] for the IPv6 flow label are also valid for this
	field. A value of zero denotes that no flow label is used. In		field. A value of zero denotes that no flow label is used. In
	this case, the flow label option is in fact unnecessary.		this case, the flow label option is in fact unnecessary.
	The Flow Label option SHOULD be copied on fragmentation. It MUST be		The Flow Label option SHOULD be copied on fragmentation. It MUST be
	the first option of the IP header and therefore MUST NOT appear more		the first option of the IP header and therefore MUST NOT appear more
	than once per IPv4 packet. The Router Alert option SHOULD NOT be		than once per IPv4 packet. The Router Alert option SHOULD NOT be
	used to mark the necessity for routers to examine the options.		used to mark the necessity for routers to examine the options.
	Placing the Flow Label option as first option allows for easy		Placing the Flow Label option as first option allows for easy
	processing in hardware.		processing in hardware.
	skipping to change at page 8, line 5 ¶		skipping to change at page 7, line 47 ¶
	"IPv6 Flow Label Specification", RFC 6437,		"IPv6 Flow Label Specification", RFC 6437,
	DOI 10.17487/RFC6437, November 2011,		DOI 10.17487/RFC6437, November 2011,
	<https://www.rfc-editor.org/info/rfc6437>.		<https://www.rfc-editor.org/info/rfc6437>.
	[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC		[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
	2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,		2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
	May 2017, <https://www.rfc-editor.org/info/rfc8174>.		May 2017, <https://www.rfc-editor.org/info/rfc8174>.
	7.2. Informative References		7.2. Informative References
	[Dre2001] Dreibholz, T., "Management of Layered Variable Bitrate
	Multimedia Streams over DiffServ with Apriori
	Knowledge", Masters Thesis, February 2001,
	<https://duepublico.uni-duisburg-
	essen.de/servlets/DerivateServlet/Derivate-29936/
	Dre2001.pdf>.
	[IJMUE2009]
	Zhu, W., Dreibholz, T., Rathgeb, E., and X. Zhou, "A
	Scalable QoS Device for Broadband Access to Multimedia
	Services", SERSC International Journal of Multimedia and
	Ubiquitous Engineering (IJMUE) Number 2, Volume 4, Pages
	157-172, ISSN 1975-0080, May 2009,
	<http://www.sersc.org/journals/IJMUE/
	vol4_no2_2009/14.pdf>.
	[RFC1633] Braden, R., Clark, D., and S. Shenker, "Integrated		[RFC1633] Braden, R., Clark, D., and S. Shenker, "Integrated
	Services in the Internet Architecture: an Overview",		Services in the Internet Architecture: an Overview",
	RFC 1633, DOI 10.17487/RFC1633, June 1994,		RFC 1633, DOI 10.17487/RFC1633, June 1994,
	<https://www.rfc-editor.org/info/rfc1633>.		<https://www.rfc-editor.org/info/rfc1633>.
	[RFC2208] Mankin, A., Ed., Baker, F., Braden, B., Bradner, S.,		[RFC2208] Mankin, A., Ed., Baker, F., Braden, B., Bradner, S.,
	O'Dell, M., Romanow, A., Weinrib, A., and L. Zhang,		O'Dell, M., Romanow, A., Weinrib, A., and L. Zhang,
	"Resource ReSerVation Protocol (RSVP) -- Version 1		"Resource ReSerVation Protocol (RSVP) -- Version 1
	Applicability Statement Some Guidelines on Deployment",		Applicability Statement Some Guidelines on Deployment",
	RFC 2208, DOI 10.17487/RFC2208, September 1997,		RFC 2208, DOI 10.17487/RFC2208, September 1997,
	skipping to change at page 8, line 43 ¶		skipping to change at page 8, line 22 ¶
	[RFC2209] Braden, R. and L. Zhang, "Resource ReSerVation Protocol		[RFC2209] Braden, R. and L. Zhang, "Resource ReSerVation Protocol
	(RSVP) -- Version 1 Message Processing Rules", RFC 2209,		(RSVP) -- Version 1 Message Processing Rules", RFC 2209,
	DOI 10.17487/RFC2209, September 1997,		DOI 10.17487/RFC2209, September 1997,
	<https://www.rfc-editor.org/info/rfc2209>.		<https://www.rfc-editor.org/info/rfc2209>.
	[RFC6436] Amante, S., Carpenter, B., and S. Jiang, "Rationale for		[RFC6436] Amante, S., Carpenter, B., and S. Jiang, "Rationale for
	Update to the IPv6 Flow Label Specification", RFC 6436,		Update to the IPv6 Flow Label Specification", RFC 6436,
	DOI 10.17487/RFC6436, November 2011,		DOI 10.17487/RFC6436, November 2011,
	<https://www.rfc-editor.org/info/rfc6436>.		<https://www.rfc-editor.org/info/rfc6436>.
			[Dre2001] Dreibholz, T., "Management of Layered Variable Bitrate
			Multimedia Streams over DiffServ with Apriori
			Knowledge", Masters Thesis, 20 February 2001,
			<https://duepublico.uni-duisburg-
			essen.de/servlets/DerivateServlet/Derivate-29936/
			Dre2001.pdf>.
			[IJMUE2009]
			Zhu, W., Dreibholz, T., Rathgeb, E. P., and X. Zhou, "A
			Scalable QoS Device for Broadband Access to Multimedia
			Services", SERSC International Journal of Multimedia and
			Ubiquitous Engineering (IJMUE) Number 2, Volume 4, Pages
			157-172, ISSN 1975-0080, May 2009,
			<http://www.sersc.org/journals/IJMUE/
			vol4_no2_2009/14.pdf>.
	Author's Address		Author's Address
	Thomas Dreibholz		Thomas Dreibholz
	Simula Metropolitan Centre for Digital Engineering		Simula Metropolitan Centre for Digital Engineering
	Pilestredet 52		Pilestredet 52
	0167 Oslo, Oslo		0167 Oslo
	Norway		Norway
	Phone: +47-6782-8200		Phone: +47-6782-8200
	Fax: +47-6782-8201
	Email: dreibh@simula.no		Email: dreibh@simula.no
	URI: https://www.simula.no/people/dreibh		URI: https://www.simula.no/people/dreibh
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