< draft-sambo-ccamp-yang-fsm-transponder-reconf-00.txt		draft-sambo-ccamp-yang-fsm-transponder-reconf-01.txt >
	CCAMP Working Group N. Sambo		CCAMP Working Group N. Sambo
	Internet-Draft P. Castoldi		Internet-Draft P. Castoldi
	Intended status: Standards Track A. Sgambelluri		Intended status: Standards Track A. Sgambelluri
	Expires: September 6, 2018 Scuola Superiore Sant'Anna		Expires: January 3, 2019 Scuola Superiore Sant'Anna
	G. Fioccola		G. Fioccola
	Telecom Italia		Telecom Italia
	F. Cugini		F. Cugini
	CNIT		CNIT
	D. Ceccarelli		D. Ceccarelli
	Ericsson		Ericsson
	H. Song		H. Song
	T. Zhou		T. Zhou
	Huawei		Huawei
	March 5, 2018		July 2, 2018
	Finite state machine YANG model augmentation for Transponder		Finite state machine YANG model augmentation for Transponder
	Reconfiguration		Reconfiguration
	draft-sambo-ccamp-yang-fsm-transponder-reconf-00		draft-sambo-ccamp-yang-fsm-transponder-reconf-01
	Abstract		Abstract
	YANG enables to compile a set of consistent vendor-neutral data		YANG enables to compile a set of consistent vendor-neutral data
	models for optical networks and components based on actual		models for optical networks and components based on actual
	operational needs emerging from heterogeneous use cases. A YANG		operational needs emerging from heterogeneous use cases. A YANG
	model has been also proposed to describe finite state machine to		model has been also proposed to describe finite state machine to
	program network elements that are modeled with YANG. This document		program network elements that are modeled with YANG. This document
	augments the more generic YANG model for finite state machine		augments the more generic YANG model for finite state machine
	[I-D.sambo-netmod-yang-fsm], in order to pre-instruct an optical		[I-D.sambo-netmod-yang-fsm], in order to pre-instruct an optical
	skipping to change at page 1, line 49 ¶		skipping to change at page 1, line 49 ¶
	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 September 6, 2018.		This Internet-Draft will expire on January 3, 2019.
	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 2, line 28 ¶		skipping to change at page 2, line 28 ¶
	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. Conventions used in this document . . . . . . . . . . . . . . 3		2. Conventions used in this document . . . . . . . . . . . . . . 3
	3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3		3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
	4. Flexible Transponders . . . . . . . . . . . . . . . . . . . . 4		4. Flexible Transponders . . . . . . . . . . . . . . . . . . . . 4
	5. Augmenting the FSM YANG model for transponder reconfiguration 7		5. Augmenting the FSM YANG model for transponder reconfiguration 7
	6. Code of the YANG model for transponder reconfiguration . . . 9		6. Code of the YANG model for transponder reconfiguration . . . 9
	7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14		7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15
	8. Security Considerations . . . . . . . . . . . . . . . . . . . 15		8. Security Considerations . . . . . . . . . . . . . . . . . . . 16
	9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15		9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
	10. References . . . . . . . . . . . . . . . . . . . . . . . . . 15		10. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
	10.1. Normative References . . . . . . . . . . . . . . . . . . 15		10.1. Normative References . . . . . . . . . . . . . . . . . . 16
	10.2. Informative References . . . . . . . . . . . . . . . . . 15		10.2. Informative References . . . . . . . . . . . . . . . . . 16
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
	1. Introduction		1. Introduction
	Networks are evolving toward more programmability, flexibility, and		Networks are evolving toward more programmability, flexibility, and
	multi-vendor interoperability. Multi-vendor interoperability can be		multi-vendor interoperability. Multi-vendor interoperability can be
	applied in the context of nodes, i.e. a node composed of components		applied in the context of nodes, i.e. a node composed of components
	provided by different vendors (named fully disaggregated white box)		provided by different vendors (named fully disaggregated white box)
	is assembled under the same control system. This way, operators can		is assembled under the same control system. This way, operators can
	optimize costs and network performance without the need of being tied		optimize costs and network performance without the need of being tied
	to single vendor equipment. NETCONF protocol RFC6241 [RFC6241] based		to single vendor equipment. NETCONF protocol RFC6241 [RFC6241] based
	skipping to change at page 7, line 37 ¶		skipping to change at page 7, line 37 ¶
	|_______________________|		|_______________________|
	Figure 3: Flow chart of the approach exploiting YANG models in this		Figure 3: Flow chart of the approach exploiting YANG models in this
	draft		draft
	5. Augmenting the FSM YANG model for transponder reconfiguration		5. Augmenting the FSM YANG model for transponder reconfiguration
	This section augments the FSM YANG model presented in		This section augments the FSM YANG model presented in
	[I-D.sambo-netmod-yang-fsm] to address the specific use case of		[I-D.sambo-netmod-yang-fsm] to address the specific use case of
	transponder reconfiguration triggered by physical layer changes. The		transponder reconfiguration triggered by physical layer changes. The
	FSM model is based on the following main attributes: states,		FSM is installed by the SDN controller in the local controller of the
	transitions (corresponding to some specific event), and actions. In		transponder and then runs there. The installation of the FSM can be
	particular, more specifically with respect to		enabled through a NETCONF <edit-config> message. Through FSM, the
	[I-D.sambo-netmod-yang-fsm], in such a use case, a state corresponds		SDN controller instructs the transponder about the possible events
	to a specific configuration of transponder transmission parameters:		(e.g., BER above a threshold) and reactions (e.g., change of
	e.g., given by the modulation format and the FEC. A transition is		modulation format) by setting the thresholds (e.g., BER threshold)
	triggered when the pre-FEC BER (or another parameter such as the		and the reconfiguration settings. The FSM model is based on the
	OSNR) is below or above a threshold. To this purpose, with respect		following main attributes: states, transitions (corresponding to some
	to [I-D.sambo-netmod-yang-fsm], the attribute <filter> is expressed		specific event), and actions. In particular, more specifically with
	by the definition of thresholds and operators. The action mainly		respect to [I-D.sambo-netmod-yang-fsm], in such a use case, a state
	consists of the change of modulation format and/or FEC.		corresponds to a specific configuration of transponder transmission
			parameters: e.g., given by the modulation format and the FEC. A
			transition is triggered when the pre-FEC BER (or another parameter
			such as the OSNR) is below or above a threshold. To this purpose,
			with respect to [I-D.sambo-netmod-yang-fsm], the attribute <filter>
			is expressed by the definition of thresholds and operators. The
			action mainly consists of the change of modulation format and/or FEC.
	The Tree of the YANG model for transponder reconfiguration		The Tree of the YANG model for transponder reconfiguration
	(augmentation of the YANG model for FSM) is reported below.		(augmentation of the YANG model for FSM) is reported below.
	module: ietf-treconf		module: ietf-treconf
	+--rw current-state? leafref		+--rw current-state? leafref
	+--rw states		+--rw states
	+--rw state [id]		+--rw state [id]
	+--rw id state-id-type		+--rw id state-id-type
	+--rw description? string		+--rw description? string
	skipping to change at page 8, line 45 ¶		skipping to change at page 9, line 4 ¶
	when an action is executed (e.g., new modulation format and FEC).		when an action is executed (e.g., new modulation format and FEC).
	For more details about the other model attributes, the reader can		For more details about the other model attributes, the reader can
	refer to [I-D.sambo-netmod-yang-fsm].		refer to [I-D.sambo-netmod-yang-fsm].
	In such a use case, we assume that an event (e.g., BER>TH) is		In such a use case, we assume that an event (e.g., BER>TH) is
	revealed by the digital signal processing (DSP) of the receiver.		revealed by the digital signal processing (DSP) of the receiver.
	Once the event is recognized, the modulation format and/or the FEC		Once the event is recognized, the modulation format and/or the FEC
	have to be changed, both at the receiver and the transmitter. Thus,		have to be changed, both at the receiver and the transmitter. Thus,
	the list of actions to be executed includes the change of		the list of actions to be executed includes the change of
	transmission parameters at the receiver side, as well as the		transmission parameters at the receiver side. Moreover, transmission
	generation of a message sent by the receiver controller to the		and receiver must be synchronized about the transmission settings
	transmitter controller to synchronize about the transmission		(modulation format and so no) for a proper transmission. Thus, when
	parameters to be adopted. This message can be sent over a control		the transponder at the receiver side decides to change its state, the
	channel between transmitter and receiver. Such transponder		remote transponder at the transmitter side has to do the same state
	reconfiguration based on FSM has been successfully demonstrated by		transition. To this purpose, the list of actions also includes this
	integrating control and data planes in a lab and field trials.		coordination. In particular, the transponder at the receiver side
			sends a message to the transmitter to synchronize about the
			transmission parameters to be adopted. This message can be sent over
			a control channel. This way both the transmitter and receiver
			operates with the same transmission parameters: e.g. the format,
			FEC, and so on.
			Such transponder reconfiguration based on FSM has been successfully
			demonstrated by integrating control and data planes in a lab and
			field trials.
			Finally, a last consideration concerns the impact on transmission bit
			rate when changing some transmission parameters. When passing from a
			more spectral efficient modulation format (but less robust with
			respect to physical impairments) to a less spectral efficient
			modulation format (more robust) such that could be polarization
			multiplexing 16 quadrature phase shift keying (PM-16QAM) and PM
			quadrature phase shift keying (PM-QPSK) the bit rate is reduced
			(halved in the case of PM-16QAM and PM-QPSK). This means that part
			of the traffic cannot be recovered through FSM, but needs of other
			restoration mechanisms (e.g., dynamic restoration). As an example,
			the gain of the proposed FSM mechanism promptly recovering part of
			the bit rate can be applied to high-priority traffic so that its
			recovery can be faster without involving central controller, while
			other classical recovery mechanisms (involving the sending of alarms,
			their processing, new computations and setup) can be adopted for best
			effort traffic (as the traffic that cannot be recovered when passing
			from PM-16QAM to PM-QPSK). The same happens changing the code rate:
			at fixed baud rate and modulation format, if the code redundancy is
			increased, the net bit rate is decreased. Again, part of the traffic
			can be promptly recovered through FSM, while the other by relying on
			classical recovery mechanisms. A future version of the draft will
			expand the list of actions also including the mechanism for recovery
			the remaining traffic.
	6. Code of the YANG model for transponder reconfiguration		6. Code of the YANG model for transponder reconfiguration
	The related code is reported below.		The related code is reported below.
	<CODE BEGINS> file "ietf-treconf@2016-03-15.yang"		<CODE BEGINS> file "ietf-treconf@2016-03-15.yang"
	module ietf-treconf {		module ietf-treconf {
	namespace "http://sssup.it/fsm";		namespace "http://sssup.it/fsm";
	prefix fsm;		prefix fsm;
	organization		organization
	"Scuola Superiore Sant'Anna Network and Services Laboratory";		"Scuola Superiore Sant'Anna Network and Services Laboratory";
	contact		contact
	" Editor: Matteo Dallaglio		" Editor: Matteo Dallaglio
	<mailto:m.dallaglio@sssup.it>		<mailto:m.dallaglio@sssup.it>
	";		";
	description		description
	"This module contains a YANG definitions of a generic finite state machine.";		"This module contains a YANG definitions of a generic finite state
			machine.";
	revision 2016-03-15 {		revision 2016-03-15 {
	description "Initial Revision.";		description "Initial Revision.";
	reference		reference
	"RFC xxxx:";		"RFC xxxx:";
	}		}
	identity TRANSITION {		identity TRANSITION {
	description "Base for all types of event";		description "Base for all types of event";
	}		}
	skipping to change at page 10, line 4 ¶		skipping to change at page 10, line 43 ¶
	"The event when the database changes.";		"The event when the database changes.";
	}		}
	// typedef statements		// typedef statements
	typedef transition-type {		typedef transition-type {
	description "it defines the transition type";		description "it defines the transition type";
	type identityref {		type identityref {
	base TRANSITION;		base TRANSITION;
	}		}
	}		}
	typedef transition-id-type {		typedef transition-id-type {
	description "it defines the transition id type";		description "it defines the transition id type";
	type uint32;		type uint32;
	}		}
	// grouping statements		// grouping statements
	grouping action-block {		grouping action-block {
	description "it defines the grouping action";		description "it defines the grouping action";
	leaf id {		leaf id {
	description "it defines the id of the transition";		description "it defines the id of the transition";
	type transition-id-type;		type transition-id-type;
	}		}
	leaf type {		leaf type {
	description "it defines if the action has to be simply executed or if a conditional statement has to be checked before execution";		description "it defines if the action has to be simply executed
			or if a conditional statement has to be checked before execution";
	type enumeration {		type enumeration {
	enum "CONDITIONAL_OP"{		enum "CONDITIONAL_OP"{
	description "it defines the type CONDITIONAL OPERATION to check a statement before execution. In this draft, at the moment, only SIMPLE will be assumed";		description "it defines the type CONDITIONAL OPERATION to check a
			statement before execution. In this draft, at the moment, only SIMPLE
			will be assumed";
	}		}
	enum "SIMPLE_OP"{		enum "SIMPLE_OP"{
	description "it defines the type SIMPLE OPERATION: i.e., an operation to be directly executed;		description "it defines the type SIMPLE OPERATION: i.e., an operation
			to be directly executed;
	}		}
	}		}
	mandatory true;		mandatory true;
	}		}
	grouping execution-top {		grouping execution-top {
	description "it defines the execution attribute";		description "it defines the execution attribute";
	anyxml execute {		anyxml execute {
	description "Represent the action to perform";		description "Represent the action to perform";
	}		}
	skipping to change at page 11, line 4 ¶		skipping to change at page 11, line 47 ¶
	description "the id of the next action to execute";		description "the id of the next action to execute";
	}		}
	}		}
	container simple {		container simple {
	when "../type = 'SIMPLE_OP'";		when "../type = 'SIMPLE_OP'";
	description		description
	"Simple execution of an action without checking any condition";		"Simple execution of an action without checking any condition";
	uses execution-top;		uses execution-top;
	}		}
	}		}
	grouping action-top {		grouping action-top {
	description "it defines the grouping of action";		description "it defines the grouping of action";
	list action {		list action {
	description "it defines the list of actions";		description "it defines the list of actions";
	key "id";		key "id";
	ordered-by user;		ordered-by user;
	uses action-block;		uses action-block;
	}		}
	}		}
	grouping on-change {		grouping on-change {
	description		description
	"Event occuring when a modification of one or more		"Event occuring when a modification of one or more
	objects occurs";		objects occurs";
	leaf threshold-parameter {		leaf threshold-parameter {
	description "it defines the threshold of an event determined by a threshold exceed";		description "it defines the threshold of an event determined by
			a threshold exceed";
	type decimal64;		type decimal64;
	}		}
	leaf threshold-operator {		leaf threshold-operator {
	description "it defines the operator to check the threshold exceed: <, > <=, >=";		description "it defines the operator to check the threshold
			exceed: <, > <=, >=";
	type string;		type string;
	}		}
	}		}
	grouping transition-top {		grouping transition-top {
	description "it defines the grouping transition";		description "it defines the grouping transition";
	leaf name {		leaf name {
	description "it defines the transition name";		description "it defines the transition name";
	type string;		type string;
	skipping to change at page 12, line 6 ¶		skipping to change at page 13, line 4 ¶
	leaf description {		leaf description {
	description "it describes the transition with a string";		description "it describes the transition with a string";
	type string;		type string;
	}		}
	// list of all possible events		// list of all possible events
	uses on-change {		uses on-change {
	when "type = 'ON_CHANGE'";		when "type = 'ON_CHANGE'";
	}		}
	container transition-action {		container transition-action {
	description "it defines the container actions to take during the transition";		description "it defines the container actions to take during the
			transition";
	uses action-top;		uses action-top;
	}		}
	}		}
	grouping transitions-top {		grouping transitions-top {
	description "it defines the grouping transition";		description "it defines the grouping transition";
	container transitions {		container transitions {
	description "it defines the container transitions";		description "it defines the container transitions";
	list transition {		list transition {
	description "it defines the list of transitions";		description "it defines the list of transitions";
End of changes. 20 change blocks.
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