< draft-pthubert-raw-problem-statement-01.txt		draft-pthubert-raw-problem-statement-02.txt >
	RAW P. Thubert, Ed.		RAW P. Thubert, Ed.
	Internet-Draft Cisco Systems		Internet-Draft Cisco Systems
	Intended status: Informational September 23, 2019		Intended status: Informational G. Papadopoulos
	Expires: March 26, 2020		Expires: April 5, 2020 IMT Atlantique
			October 3, 2019
	Reliable and Available Wireless Problem Statement		Reliable and Available Wireless Problem Statement
	draft-pthubert-raw-problem-statement-01		draft-pthubert-raw-problem-statement-02
	Abstract		Abstract
	Due to uncontrolled interferences, including the self-induced		Due to uncontrolled interferences, including the self-induced
	multipath fading, deterministic networking can only be approached on		multipath fading, deterministic networking can only be approached on
	wireless links. The radio conditions may change -way- faster than a		wireless links. The radio conditions may change -way- faster than a
	centralized routing can adapt and reprogram, in particular when the		centralized routing can adapt and reprogram, in particular when the
	controller is distant and connectivity is slow and limited. RAW		controller is distant and connectivity is slow and limited. RAW
	separates the routing time scale at which a complex path is		separates the routing time scale at which a complex path is
	recomputed from the forwarding time scale at which the forwarding		recomputed from the forwarding time scale at which the forwarding
	skipping to change at page 1, line 41 ¶		skipping to change at page 1, line 42 ¶
	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 26, 2020.		This Internet-Draft will expire on April 5, 2020.
	Copyright Notice		Copyright Notice
	Copyright (c) 2019 IETF Trust and the persons identified as the		Copyright (c) 2019 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 2, line 18 ¶		skipping to change at page 2, line 21 ¶
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. Use Cases and Requirements Served . . . . . . . . . . . . . . 4		2. Use Cases and Requirements Served . . . . . . . . . . . . . . 4
	3. Routing Scale vs. Forwarding Scale . . . . . . . . . . . . . 4		3. Routing Scale vs. Forwarding Scale . . . . . . . . . . . . . 4
	4. Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . 5		4. Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . 5
	5. Functional Gaps . . . . . . . . . . . . . . . . . . . . . . . 5		5. Related Work at The IETF . . . . . . . . . . . . . . . . . . 6
	6. References . . . . . . . . . . . . . . . . . . . . . . . . . 6		6. Functional Gaps . . . . . . . . . . . . . . . . . . . . . . . 6
	6.1. Normative References . . . . . . . . . . . . . . . . . . 6		7. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
	6.2. Informative References . . . . . . . . . . . . . . . . . 7		7.1. Normative References . . . . . . . . . . . . . . . . . . 7
	Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 7		7.2. Informative References . . . . . . . . . . . . . . . . . 8
			Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
	1. Introduction		1. Introduction
	Bringing determinism in a packet network means eliminating the		Bringing determinism in a packet network means eliminating the
	statistical effects of multiplexing that result in probabilistic		statistical effects of multiplexing that result in probabilistic
	jitter and loss. This can be approached with a tight control of the		jitter and loss. This can be approached with a tight control of the
	physical resources to maintain the amount of traffic within a		physical resources to maintain the amount of traffic within a
	budgetted volume of data per unit of time that fits the physical		budgetted volume of data per unit of time that fits the physical
	capabilities of the underlying technology, and the use of time-shared		capabilities of the underlying technology, and the use of time-shared
	resources (bandwidth and buffers) per circuit, and/or by shaping and/		resources (bandwidth and buffers) per circuit, and/or by shaping and/
	skipping to change at page 5, line 46 ¶		skipping to change at page 6, line 5 ¶
	radio with some guarantees in terms of service reliability, e.g., it		radio with some guarantees in terms of service reliability, e.g., it
	can be relied upon to transmit a packet within a bounded latency and		can be relied upon to transmit a packet within a bounded latency and
	provides a guaranteed BER/PDR outside rare but existing transient		provides a guaranteed BER/PDR outside rare but existing transient
	outage windows that can last from split seconds to minutes. The		outage windows that can last from split seconds to minutes. The
	radio layer can be programmed with abstract parameters, and can		radio layer can be programmed with abstract parameters, and can
	return an abstract view of the state of the Link to help forwarding		return an abstract view of the state of the Link to help forwarding
	decision (think DLEP from MANET). In the layered approach, how the		decision (think DLEP from MANET). In the layered approach, how the
	radio manages its PHY layer is out of control and out of scope.		radio manages its PHY layer is out of control and out of scope.
	Whether it is single hop or meshed is also unknown and out of scope.		Whether it is single hop or meshed is also unknown and out of scope.
	5. Functional Gaps		5. Related Work at The IETF
			RAW intersects with protocols or practices in development at the IETF
			as follows:
			o The Dynamic Link Exchange Protocol [RFC8175] (DLEP) from [MANET]
			can be leveraged at each hop to derive generic radio metrics
			(e.g., based on LQI, RSSI, queueing delays and ETX) on individual
			hops
			o Operations, Administration and Maintenance (OAM) work at [DetNet]
			such as [I-D.mirsky-detnet-ip-oam] for the case of the IP Data
			Plane observes the state of DetNet paths, typically MPLS and IPv6
			pseudowires [I-D.ietf-detnet-data-plane-framework], in the
			direction of the traffic. RAW needs feedback that flows on the
			reverse path and gathers instantaneous values from the radio
			receivers at each hop to inform back the source and replicating
			relays so they can make optimized forwarding decisions. The work
			named ICAN may be related and may find a home at RAW.
			o [BFD] detect faults in the path between an ingress and an egress
			forwarding engines, but is aware of the complexity of a path with
			replication, and expects bidirectionality. BFD considers delivery
			as success whereas with RAW the bounded latency can be as
			important as the delivery itself.
			o [SPRING] and [BIER] define in-band signaling that influences the
			routing when decided at the head-end on the path. There's already
			one RAW-related draft at BIER
			[I-D.thubert-bier-replication-elimination] more may follow. RAW
			will need new in-band signaling when the decision is distributed,
			e.g., required chances of reliable delivery to destination within
			latency. This signaling enables relays to tune retries and
			replication to be met.
			o [CCAMP] defines protocol-independent metrics and parameters
			(measurement attributes) for describing links and paths that are
			required for routing and signaling in technology-specific
			networks. RAW would be a source of requirements for CCAMP to
			define metrics that are significant to the focus radios.
			6. Functional Gaps
	Within a large routed topology, the routing operation builds a		Within a large routed topology, the routing operation builds a
	particular complex Track with one source and one or more		particular complex Track with one source and one or more
	destinations; within the Track, packets may follows different paths		destinations; within the Track, packets may follows different paths
	and may be subject to RAW forwarding operations that include		and may be subject to RAW forwarding operations that include
	replication, elimination, retries, overhearing and reordering.		replication, elimination, retries, overhearing and reordering.
	The RAW forwarding decisions include the selection of points of		The RAW forwarding decisions include the selection of points of
	replication and elimination, how many retries can take place, and a		replication and elimination, how many retries can take place, and a
	limit of validity for the packet beyond which the packet should be		limit of validity for the packet beyond which the packet should be
	destroyed rather than forwarded uselessly further down the Track.		destroyed rather than forwarded uselessly further down the Track.
	The decision to apply the RAW techniques must be done quickly, and		The decision to apply the RAW techniques must be done quickly, and
	depends on a very recent and precise knowledge of the forwarding		depends on a very recent and precise knowledge of the forwarding
	conditions withing the complex Track. There is a need for an		conditions within the complex Track. There is a need for an
	observation method to provide the RAW forwarding plane with the		observation method to provide the RAW forwarding plane with the
	specific knowledge of the state of the Track for the type of flow of		specific knowledge of the state of the Track for the type of flow of
	interest (e.g., for a QoS level of interest). To observe the whole		interest (e.g., for a QoS level of interest). To observe the whole
	Track in quasi real time, RAW will consider existing tools such as		Track in quasi real time, RAW will consider existing tools such as
	L2-triggers, DLEP, BFD and in-band and out-of-band OAM.		L2-triggers, DLEP, BFD and in-band and out-of-band OAM.
	One possible way of making the RAW forwarding decisions is to make		One possible way of making the RAW forwarding decisions is to make
	them all at the ingress and express them in-band in the packet, which		them all at the ingress and express them in-band in the packet, which
	requires new loose or strict Hop-by-hop signaling. To control the		requires new loose or strict Hop-by-hop signaling. To control the
	RAW forwarding operation along a Track for the individual packets,		RAW forwarding operation along a Track for the individual packets,
	RAW may leverage and extend known techniques such as Segment Routing		RAW may leverage and extend known techniques such as DetNet tagging,
	(SRv6) or BIER-TE such as done with		Segment Routing (SRv6) or BIER-TE such as done with
	[I-D.thubert-bier-replication-elimination].		[I-D.thubert-bier-replication-elimination].
	An alternate way is to enable each forwarding node to make the RAW		An alternate way is to enable each forwarding node to make the RAW
	forwarding decisions for a packet on its own, based on its knowledge		forwarding decisions for a packet on its own, based on its knowledge
	of the expectation (timeliness and reliability) for that packet and a		of the expectation (timeliness and reliability) for that packet and a
	recent observation of the rest of the way across the possible paths		recent observation of the rest of the way across the possible paths
	within the Track. Information about the service should be placed in		within the Track. Information about the service should be placed in
	the packet and matched with the forwarding node's capabilities and		the packet and matched with the forwarding node's capabilities and
	policies.		policies.
	In either case, a per-flow state is installed in all intermediate		In either case, a per-flow state is installed in all intermediate
	nodes to recognize the flow and determine the forwarding policy to be		nodes to recognize the flow and determine the forwarding policy to be
	applied.		applied.
	6. References		7. References
	6.1. Normative References		7.1. Normative References
	[I-D.bernardos-raw-use-cases]		[I-D.bernardos-raw-use-cases]
	Papadopoulos, G., Thubert, P., Theoleyre, F., and C.		Papadopoulos, G., Thubert, P., Theoleyre, F., and C.
	Bernardos, "RAW use cases", draft-bernardos-raw-use-		Bernardos, "RAW use cases", draft-bernardos-raw-use-
	cases-00 (work in progress), July 2019.		cases-00 (work in progress), July 2019.
	[I-D.ietf-6tisch-architecture]		[I-D.ietf-6tisch-architecture]
	Thubert, P., "An Architecture for IPv6 over the TSCH mode		Thubert, P., "An Architecture for IPv6 over the TSCH mode
	of IEEE 802.15.4", draft-ietf-6tisch-architecture-26 (work		of IEEE 802.15.4", draft-ietf-6tisch-architecture-26 (work
	in progress), August 2019.		in progress), August 2019.
	skipping to change at page 7, line 16 ¶		skipping to change at page 8, line 16 ¶
	Finn, N., Thubert, P., Varga, B., and J. Farkas,		Finn, N., Thubert, P., Varga, B., and J. Farkas,
	"Deterministic Networking Architecture", draft-ietf-		"Deterministic Networking Architecture", draft-ietf-
	detnet-architecture-13 (work in progress), May 2019.		detnet-architecture-13 (work in progress), May 2019.
	[I-D.thubert-raw-technologies]		[I-D.thubert-raw-technologies]
	Thubert, P., Cavalcanti, D., Vilajosana, X., and C.		Thubert, P., Cavalcanti, D., Vilajosana, X., and C.
	Schmitt, "Reliable and Available Wireless Technologies",		Schmitt, "Reliable and Available Wireless Technologies",
	draft-thubert-raw-technologies-03 (work in progress), July		draft-thubert-raw-technologies-03 (work in progress), July
	2019.		2019.
			[RFC8175] Ratliff, S., Jury, S., Satterwhite, D., Taylor, R., and B.
			Berry, "Dynamic Link Exchange Protocol (DLEP)", RFC 8175,
			DOI 10.17487/RFC8175, June 2017,
			<https://www.rfc-editor.org/info/rfc8175>.
	[RFC8578] Grossman, E., Ed., "Deterministic Networking Use Cases",		[RFC8578] Grossman, E., Ed., "Deterministic Networking Use Cases",
	RFC 8578, DOI 10.17487/RFC8578, May 2019,		RFC 8578, DOI 10.17487/RFC8578, May 2019,
	<https://www.rfc-editor.org/info/rfc8578>.		<https://www.rfc-editor.org/info/rfc8578>.
	6.2. Informative References		7.2. Informative References
			[BFD] IETF, "Bidirectional Forwarding Detection",
			<https://dataTracker.ietf.org/doc/charter-ietf-bfd/>.
			[BIER] IETF, "Bit Indexed Explicit Replication",
			<https://dataTracker.ietf.org/doc/charter-ietf-bier/>.
	[CCAMP] IETF, "Common Control and Measurement Plane",		[CCAMP] IETF, "Common Control and Measurement Plane",
	<https://dataTracker.ietf.org/doc/charter-ietf-ccamp/>.		<https://dataTracker.ietf.org/doc/charter-ietf-ccamp/>.
			[DetNet] IETF, "Deterministic Networking",
			<https://dataTracker.ietf.org/doc/charter-ietf-detnet/>.
			[I-D.ietf-detnet-data-plane-framework]
			Varga, B., Farkas, J., Berger, L., Fedyk, D., Malis, A.,
			Bryant, S., and J. Korhonen, "DetNet Data Plane
			Framework", draft-ietf-detnet-data-plane-framework-02
			(work in progress), September 2019.
			[I-D.mirsky-detnet-ip-oam]
			Mirsky, G. and M. Chen, "Operations, Administration and
			Maintenance (OAM) for Deterministic Networks (DetNet) with
			IP Data Plane", draft-mirsky-detnet-ip-oam-00 (work in
			progress), July 2019.
	[I-D.thubert-bier-replication-elimination]		[I-D.thubert-bier-replication-elimination]
	Thubert, P., Eckert, T., Brodard, Z., and H. Jiang, "BIER-		Thubert, P., Eckert, T., Brodard, Z., and H. Jiang, "BIER-
	TE extensions for Packet Replication and Elimination		TE extensions for Packet Replication and Elimination
	Function (PREF) and OAM", draft-thubert-bier-replication-		Function (PREF) and OAM", draft-thubert-bier-replication-
	elimination-03 (work in progress), March 2018.		elimination-03 (work in progress), March 2018.
			[MANET] IETF, "Mobile Ad hoc Networking",
			<https://dataTracker.ietf.org/doc/charter-ietf-manet/>.
	[PCE] IETF, "Path Computation Element",		[PCE] IETF, "Path Computation Element",
	<https://dataTracker.ietf.org/doc/charter-ietf-pce/>.		<https://dataTracker.ietf.org/doc/charter-ietf-pce/>.
			[SPRING] IETF, "Source Packet Routing in Networking",
			<https://dataTracker.ietf.org/doc/charter-ietf-spring/>.
	[TEAS] IETF, "Traffic Engineering Architecture and Signaling",		[TEAS] IETF, "Traffic Engineering Architecture and Signaling",
	<https://dataTracker.ietf.org/doc/charter-ietf-teas/>.		<https://dataTracker.ietf.org/doc/charter-ietf-teas/>.
	Author's Address		Authors' Addresses
	Pascal Thubert (editor)		Pascal Thubert (editor)
	Cisco Systems, Inc		Cisco Systems, Inc
	Building D		Building D
	45 Allee des Ormes - BP1200		45 Allee des Ormes - BP1200
	MOUGINS - Sophia Antipolis 06254		MOUGINS - Sophia Antipolis 06254
	FRANCE		FRANCE
	Phone: +33 497 23 26 34		Phone: +33 497 23 26 34
	Email: pthubert@cisco.com		Email: pthubert@cisco.com
			Georgios Z. Papadopoulos
			IMT Atlantique
			Office B00 - 114A
			2 Rue de la Chataigneraie
			Cesson-Sevigne - Rennes 35510
			FRANCE
			Phone: +33 299 12 70 04
			Email: georgios.papadopoulos@imt-atlantique.fr
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