< draft-ietf-detnet-problem-statement-04.txt		draft-ietf-detnet-problem-statement-05.txt >
	detnet N. Finn		detnet N. Finn
	Internet-Draft Huawei Technologies Co. Ltd		Internet-Draft Huawei Technologies Co. Ltd
	Intended status: Informational P. Thubert		Intended status: Informational P. Thubert
	Expires: December 8, 2018 Cisco		Expires: December 24, 2018 Cisco
	June 6, 2018		June 22, 2018
	Deterministic Networking Problem Statement		Deterministic Networking Problem Statement
	draft-ietf-detnet-problem-statement-04		draft-ietf-detnet-problem-statement-05
	Abstract		Abstract
	This paper documents the needs in various industries to establish		This paper documents the needs in various industries to establish
	multi-hop paths for characterized flows with deterministic properties		multi-hop paths for characterized flows with deterministic
	.		properties.
	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
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	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 December 8, 2018.		This Internet-Draft will expire on December 24, 2018.
	Copyright Notice		Copyright Notice
	Copyright (c) 2018 IETF Trust and the persons identified as the		Copyright (c) 2018 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 3, line 28 ¶		skipping to change at page 3, line 28 ¶
	flows.		flows.
	Once the abstract model is agreed upon, the IETF will need to specify		Once the abstract model is agreed upon, the IETF will need to specify
	the signaling elements to be used to establish a path and the tagging		the signaling elements to be used to establish a path and the tagging
	elements to be used identify the flows that are to be forwarded along		elements to be used identify the flows that are to be forwarded along
	that path. The IETF will also need to specify the necessary		that path. The IETF will also need to specify the necessary
	protocols, or protocol additions, based on relevant IETF		protocols, or protocol additions, based on relevant IETF
	technologies, to implement the selected model.		technologies, to implement the selected model.
	As a result of this work, it will be possible to establish a multi-		As a result of this work, it will be possible to establish a multi-
	hop path over the IP network, for a particular flow with given timing		hop path over the IP or MPLS network, for a particular flow with
	and precise throughput requirements, and carry this particular flow		given timing and precise throughput requirements, and carry this
	along the multi-hop path with such characteristics as low latency and		particular flow along the multi-hop path with such characteristics as
	ultra-low jitter, duplication and elimination of packets over non-		low latency and ultra-low jitter, reordering and/or replication and
	congruent paths for a higher delivery ratio, and/or zero congestion		elimination of packets over non-congruent paths for a higher delivery
	loss, regardless of the amount of other flows in the network.		ratio, and/or zero congestion loss, regardless of the amount of other
			flows in the network.
	Depending on the network capabilities and on the current state,		Depending on the network capabilities and on the current state,
	requests to establish a path by an end-node or a network management		requests to establish a path by an end-node or a network management
	entity may be granted or rejected, an existing path may be moved or		entity may be granted or rejected, an existing path may be moved or
	removed, and DetNet flows exceeding their contract may face packet		removed, and DetNet flows exceeding their contract may face packet
	declassification and drop.		declassification and drop.
	2. On Deterministic Networking		2. On Deterministic Networking
	The Internet is not the only digital network that has grown		The Internet is not the only digital network that has grown
	dramatically over the last 30-40 years. Video and audio		dramatically over the last 30-40 years. Video and audio
	entertainment, and control systems for machinery, manufacturing		entertainment, and control systems for machinery, manufacturing
	processes, and vehicles are also ubiquitous, and are now based almost		processes, and vehicles are also ubiquitous, and are now based almost
	entirely on digital technologies. Over the past 10 years, engineers		entirely on digital technologies. Over the past 10 years, engineers
	in these fields have come to realize that significant advantages in		in these fields have come to realize that significant advantages in
	both cost and in the ability to accelerate growth can be obtained by		both cost and in the ability to accelerate growth can be obtained by
	basing all of these disparate digital technologies on packet		basing all of these disparate digital technologies on packet
	networks.		networks.
	The goals of Deterministic Networking are to enable the migration of		The goals of Deterministic Networking (DetNet) are to enable the
	applications with critical timing and reliability issues that		migration of applications with critical timing and reliability issues
	currently use special-purpose fieldbus technologies (HDMI, CANbus,		that currently use special-purpose fieldbus technologies (HDMI,
	ProfiBus, etc... even RS-232!) to packet technologies in general, and		CANbus, ProfiBus, etc... even RS-232!) to packet technologies in
	the Internet Protocol in particular, and to support both these new		general, and the Internet Protocol in particular, and to support both
	applications, and existing packet network applications, over the same		these new applications, and existing packet network applications,
	physical network.		over the same physical network.
	Considerable experience ([ODVA]/[EIP],[AVnu],		Considerable experience ([ODVA]/[EIP],[AVnu],
	[Profinet],[HART],[IEC62439], [ISA100.11a] and [WirelessHART],		[Profinet],[HART],[IEC62439], [ISA100.11a] and [WirelessHART],
	etc...) has shown that these applications need a some or all of a		etc...) has shown that these applications need a some or all of a
	suite of features that includes:		suite of features that includes:
	1. Time synchronization of all host and network nodes (routers and/		1. Time synchronization of all host and network nodes (routers and/
	or bridges), accurate to something between 10 nanoseconds and 10		or bridges), accurate to something between 10 nanoseconds and 10
	microseconds, depending on the application.		microseconds, depending on the application.
	skipping to change at page 6, line 36 ¶		skipping to change at page 6, line 38 ¶
	3.2. Flow Characterization		3.2. Flow Characterization
	Deterministic forwarding can only apply on flows with well-defined		Deterministic forwarding can only apply on flows with well-defined
	characteristics such as periodicity and burstiness. Before a path		characteristics such as periodicity and burstiness. Before a path
	can be established to serve them, the expression of those		can be established to serve them, the expression of those
	characteristics, and how the network can serve them, for instance in		characteristics, and how the network can serve them, for instance in
	shaping and forwarding operations, must be specified.		shaping and forwarding operations, must be specified.
	3.3. Centralized Path Computation and Installation		3.3. Centralized Path Computation and Installation
	A centralized routing model, such as provided with a PCE, enables		A centralized routing model, such as provided with a Path Computation
	global and per-flow optimizations. The model is attractive but a		Element (PCE) (see [RFC4655]), enables global and per-flow
	number of issues are left to be solved. In particular:		optimizations. The model is attractive but a number of issues are
			left to be solved. In particular:
	o whether and how the path computation can be installed by 1) an end		o whether and how the path computation can be installed by 1) an end
	device or 2) a Network Management entity,		device or 2) a Network Management entity,
	o and how the path is set up, either by installing state at each hop		o and how the path is set up, either by installing state at each hop
	with a direct interaction between the forwarding device and the		with a direct interaction between the forwarding device and the
	PCE, or along a path by injecting a source-routed request at one		PCE, or along a path by injecting a source-routed request at one
	end of the path following classical Traffic Engineering (TE)		end of the path following classical Traffic Engineering (TE)
	models.		models.
	To enable a centralized model, DetNet should produce the complete SDN		To enable a centralized model, DetNet should produce a description of
	architecture with describes at a high level the interaction and data		the high level interaction and data models to:
	models to:
	o report the topology and device capabilities to the central		o report the topology and device capabilities to the central
	controller;		controller;
	o establish a direct interface between the centralized PCE to each		o establish a direct interface between the centralized PCE to each
	device under its control in order to enable a vertical signaling		device under its control in order to enable a vertical signaling
	o request a path setup for a new flow with particular		o request a path setup for a new flow with particular
	characteristics over the service interface and control it through		characteristics over the service interface and control it through
	its life cycle;		its life cycle;
	skipping to change at page 7, line 43 ¶		skipping to change at page 7, line 46 ¶
	But the focus of the work should be to deliver the centralized		But the focus of the work should be to deliver the centralized
	approach first.		approach first.
	To enable a RSVP-TE like functionality, the following steps would		To enable a RSVP-TE like functionality, the following steps would
	take place:		take place:
	1. Neighbors and their capabilities are discovered and exposed to		1. Neighbors and their capabilities are discovered and exposed to
	compute a path that fits the DetNet constraints, typically of		compute a path that fits the DetNet constraints, typically of
	latency, time precision and resource availability.		latency, time precision and resource availability.
	2. A constrained path is calculated with an improved version of CSPF		2. A constrained path is calculated with an improved version of
	that is aware of DetNet.		Constrained Shortest Path First (CSPF) that is aware of DetNet.
	3. The path may be installed using a control protocol such as RSVP-		3. The path may be installed using a control protocol such as RSVP-
	TE, associated with flow identification, per-hop behavior such as		TE, associated with flow identification, per-hop behavior such as
	Packet Replication and Elimination, blocked resources, and flow		Packet Replication and Elimination, blocked resources, and flow
	timing information. Alternatively, the routing and flow		timing information. In that case, traffic flows can be
	information may be placed in-band in the packet, e.g., using		transported through an MPLS-TE tunnel, using the reserved
	Segment Routing, in which case the packet is routed along a		resources for this flow at each hop.
	prescribed source route path following forwarding indications
	that are present in the packet.
	4. Traffic flows are transported through the MPLS-TE tunnel, using		4. Alternatively, the routing and flow information may be placed in-
	the reserved resources for this flow at each hop.		band in the IP packet, e.g., using Segment Routing and/or IPv6
			Routing and Option Headers, in which case the packet is routed
			along a prescribed source route path following forwarding
			indications that are present in the packet.
	3.5. Duplicated data format		3.5. Duplicated data format
	In some cases the duplication and elimination of packets over non-		In some cases the duplication and elimination of packets over non-
	congruent paths is required to achieve a sufficiently high delivery		congruent paths is required to achieve a sufficiently high delivery
	ratio to meet application needs. In these cases, a small number of		ratio to meet application needs. In these cases, a small number of
	packet formats and supporting protocols are required (preferably,		packet formats and supporting protocols are required (preferably,
	just one) to serialize the packets of a DetNet stream at one point in		just one) to serialize the packets of a DetNet stream at one point in
	the network, replicate them at one or more points in the network, and		the network, replicate them at one or more points in the network, and
	discard duplicates at one or more other points in the network,		discard duplicates at one or more other points in the network,
	skipping to change at page 9, line 4 ¶		skipping to change at page 9, line 8 ¶
	associated with a given flow at a given point of time. In that		associated with a given flow at a given point of time. In that
	model, Time Sharing of physical resources becomes transparent to the		model, Time Sharing of physical resources becomes transparent to the
	individual flows which have no clue whether the resources are used by		individual flows which have no clue whether the resources are used by
	other flows at other times.		other flows at other times.
	The overall security of a deterministic system must cover:		The overall security of a deterministic system must cover:
	o the protection of the signaling protocol		o the protection of the signaling protocol
	o the authentication and authorization of the controlling nodes		o the authentication and authorization of the controlling nodes
			including plug-and-play participating end systems.
	o the identification and shaping of the flows		o the identification and shaping of the flows
	o the isolation of flows from leakage and other influences from any		o the isolation of flows from leakage and other influences from any
	activity sharing physical resources.		activity sharing physical resources.
	5. IANA Considerations		5. IANA Considerations
	This document does not require an action from IANA.		This document does not require an action from IANA.
	6. Acknowledgments		6. Acknowledgments
	skipping to change at page 10, line 41 ¶		skipping to change at page 10, line 41 ¶
	[Profinet]		[Profinet]
	http://us.profinet.com/technology/profinet/, "PROFINET is		http://us.profinet.com/technology/profinet/, "PROFINET is
	a standard for industrial networking in automation.",		a standard for industrial networking in automation.",
	<http://us.profinet.com/technology/profinet/>.		<http://us.profinet.com/technology/profinet/>.
	[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,		[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
	and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP		and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
	Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,		Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
	<https://www.rfc-editor.org/info/rfc3209>.		<https://www.rfc-editor.org/info/rfc3209>.
			[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
			Element (PCE)-Based Architecture", RFC 4655,
			DOI 10.17487/RFC4655, August 2006,
			<https://www.rfc-editor.org/info/rfc4655>.
	[RFC7384] Mizrahi, T., "Security Requirements of Time Protocols in		[RFC7384] Mizrahi, T., "Security Requirements of Time Protocols in
	Packet Switched Networks", RFC 7384, DOI 10.17487/RFC7384,		Packet Switched Networks", RFC 7384, DOI 10.17487/RFC7384,
	October 2014, <https://www.rfc-editor.org/info/rfc7384>.		October 2014, <https://www.rfc-editor.org/info/rfc7384>.
	[WirelessHART]		[WirelessHART]
	www.hartcomm.org, "Industrial Communication Networks -		www.hartcomm.org, "Industrial Communication Networks -
	Wireless Communication Network and Communication Profiles		Wireless Communication Network and Communication Profiles
	- WirelessHART - IEC 62591", 2010.		- WirelessHART - IEC 62591", 2010.
	Authors' Addresses		Authors' Addresses
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