< draft-ietf-lpwan-schc-over-lorawan-02.txt		draft-ietf-lpwan-schc-over-lorawan-03.txt >
	lpwan Working Group O. Gimenez, Ed.		lpwan Working Group O. Gimenez, Ed.
	Internet-Draft Semtech		Internet-Draft Semtech
	Intended status: Informational I. Petrov, Ed.		Intended status: Informational I. Petrov, Ed.
	Expires: January 9, 2020 Acklio		Expires: April 11, 2020 Acklio
	July 08, 2019		J. Catalano
			Kerlink
			October 09, 2019
	Static Context Header Compression (SCHC) over LoRaWAN		Static Context Header Compression (SCHC) over LoRaWAN
	draft-ietf-lpwan-schc-over-lorawan-02		draft-ietf-lpwan-schc-over-lorawan-03
	Abstract		Abstract
	The Static Context Header Compression (SCHC) specification describes		The Static Context Header Compression (SCHC) specification describes
	generic header compression and fragmentation techniques for LPWAN		generic header compression and fragmentation techniques for LPWAN
	(Low Power Wide Area Networks) technologies. SCHC is a generic		(Low Power Wide Area Networks) technologies. SCHC is a generic
	mechanism designed for great flexibility, so that it can be adapted		mechanism designed for great flexibility so that it can be adapted
	for any of the LPWAN technologies.		for any of the LPWAN technologies.
	This document provides the adaptation of SCHC for use in LoRaWAN		This document provides the adaptation of SCHC for use in LoRaWAN
	networks, and provides elements such as efficient parameterization		networks, and provides elements such as efficient parameterization
	and modes of operation. This is called a profile.		and modes of operation. This is called a profile.
	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.
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	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 January 9, 2020.		This Internet-Draft will expire on April 11, 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
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	3. Static Context Header Compression Overview . . . . . . . . . 3		3. Static Context Header Compression Overview . . . . . . . . . 3
	4. LoRaWAN Architecture . . . . . . . . . . . . . . . . . . . . 5		4. LoRaWAN Architecture . . . . . . . . . . . . . . . . . . . . 5
	4.1. End-Device classes (A, B, C) and interactions . . . . . . 6		4.1. End-Device classes (A, B, C) and interactions . . . . . . 6
	4.2. End-Device addressing . . . . . . . . . . . . . . . . . . 7		4.2. End-Device addressing . . . . . . . . . . . . . . . . . . 7
	4.3. General Message Types . . . . . . . . . . . . . . . . . . 7		4.3. General Message Types . . . . . . . . . . . . . . . . . . 7
	4.4. LoRaWAN MAC Frames . . . . . . . . . . . . . . . . . . . 8		4.4. LoRaWAN MAC Frames . . . . . . . . . . . . . . . . . . . 8
	5. SCHC-over-LoRaWAN . . . . . . . . . . . . . . . . . . . . . . 8		5. SCHC-over-LoRaWAN . . . . . . . . . . . . . . . . . . . . . . 8
	5.1. LoRaWAN FPort . . . . . . . . . . . . . . . . . . . . . . 8		5.1. LoRaWAN FPort . . . . . . . . . . . . . . . . . . . . . . 8
	5.2. Rule ID management . . . . . . . . . . . . . . . . . . . 9		5.2. Rule ID management . . . . . . . . . . . . . . . . . . . 9
	5.3. IID computation . . . . . . . . . . . . . . . . . . . . . 9		5.3. IID computation . . . . . . . . . . . . . . . . . . . . . 9
	5.4. Fragmentation . . . . . . . . . . . . . . . . . . . . . . 9		5.4. Padding . . . . . . . . . . . . . . . . . . . . . . . . . 10
	5.5. DTag . . . . . . . . . . . . . . . . . . . . . . . . . . 9		5.5. Compression . . . . . . . . . . . . . . . . . . . . . . . 10
	5.5.1. Uplink fragmentation: From device to SCHC gateway . . 10		5.6. Fragmentation . . . . . . . . . . . . . . . . . . . . . . 10
	5.5.2. Downlink fragmentation: From SCHC gateway to device . 13		5.6.1. DTag . . . . . . . . . . . . . . . . . . . . . . . . 10
			5.6.2. Uplink fragmentation: From device to SCHC gateway . . 10
			5.6.3. Downlink fragmentation: From SCHC gateway to a device 13
	6. Security considerations . . . . . . . . . . . . . . . . . . . 16		6. Security considerations . . . . . . . . . . . . . . . . . . . 16
	Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 17		Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 17
	Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 17		Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 17
	9. References . . . . . . . . . . . . . . . . . . . . . . . . . 17		9. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
	9.1. Normative References . . . . . . . . . . . . . . . . . . 17		9.1. Normative References . . . . . . . . . . . . . . . . . . 17
	9.2. Informative References . . . . . . . . . . . . . . . . . 18		9.2. Informative References . . . . . . . . . . . . . . . . . 18
	Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 18		Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 18
	A.1. Uplink - Compression example - No fragmentation . . . . . 18		A.1. Uplink - Compression example - No fragmentation . . . . . 18
	A.2. Uplink - Compression and fragmentation example . . . . . 19		A.2. Uplink - Compression and fragmentation example . . . . . 19
	A.3. Downlink . . . . . . . . . . . . . . . . . . . . . . . . 20		A.3. Downlink . . . . . . . . . . . . . . . . . . . . . . . . 20
	skipping to change at page 3, line 16 ¶		skipping to change at page 3, line 20 ¶
	communicate with other Internet networks. However, for efficient		communicate with other Internet networks. However, for efficient
	performance, some parameters and modes of operation need to be set		performance, some parameters and modes of operation need to be set
	appropriately for each of the LPWAN technologies.		appropriately for each of the LPWAN technologies.
	This document describes the efficient parameters and modes of		This document describes the efficient parameters and modes of
	operation when SCHC is used over LoRaWAN networks.		operation when SCHC is used over LoRaWAN networks.
	2. Terminology		2. Terminology
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this		"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
	document are to be interpreted as described in [RFC2119].		"OPTIONAL" in this document are to be interpreted as described in BCP
			14 [RFC2119] [RFC8174] when, and only when, they appear in all
			capitals, as shown here.
	This section defines the terminology and acronyms used in this		This section defines the terminology and acronyms used in this
	document. For all other definitions, please look up the SCHC		document. For all other definitions, please look up the SCHC
	specification [I-D.ietf-lpwan-ipv6-static-context-hc].		specification [I-D.ietf-lpwan-ipv6-static-context-hc].
	o DevEUI: an IEEE EUI-64 identifier used to identify the end-device		o DevEUI: an IEEE EUI-64 identifier used to identify the end-device
	during the procedure while joining the network (Join Procedure)		during the procedure while joining the network (Join Procedure)
	o DevAddr: a 32-bit non-unique identifier assigned to a end-device		o DevAddr: a 32-bit non-unique identifier assigned to an end-device
	statically or dynamically after a Join Procedure (depending on the		statically or dynamically after a Join Procedure (depending on the
	activation mode)		activation mode)
			o RCS: Reassembly Check Sequence. Used to verify the integrity of
			the fragmentation-reassembly process
	o TBD: all significant LoRaWAN-related terms.		o TBD: all significant LoRaWAN-related terms.
	3. Static Context Header Compression Overview		3. Static Context Header Compression Overview
	This section contains a short overview of Static Context Header		This section contains a short overview of Static Context Header
	Compression (SCHC). For a detailed description, refer to the full		Compression (SCHC). For a detailed description, refer to the full
	specification [I-D.ietf-lpwan-ipv6-static-context-hc].		specification [I-D.ietf-lpwan-ipv6-static-context-hc].
	Static Context Header Compression (SCHC) avoids context		Static Context Header Compression (SCHC) avoids context
	synchronization, based on the fact that the nature of data flows is		synchronization, based on the fact that the nature of data flows is
	highly predictable in LPWAN networks, some static contexts may be		highly predictable in LPWAN networks, some static contexts may be
	stored on the Device (Dev). The contexts must be stored in both		stored on the Device (Dev). The context MUST be stored in both ends,
	ends, and it can either be learned by a provisioning protocol or by		and it can either be learned by a provisioning protocol or by out-of-
	out-of-band means or it can be pre-provisioned, etc. The way the		band means or it can be pre-provisioned, etc. The way the context is
	context is learned on both sides is out of the scope of this		learned on both sides is outside the scope of this document.
	document.
	Dev App		Dev App
	+----------------+ +----+ +----+ +----+		+----------------+ +----+ +----+ +----+
	| App1 App2 App3 | |App1| |App2| |App3|		| App1 App2 App3 | |App1| |App2| |App3|
	| | | | | | | |		| | | | | | | |
	| UDP | |UDP | |UDP | |UDP |		| UDP | |UDP | |UDP | |UDP |
	| IPv6 | |IPv6| |IPv6| |IPv6|		| IPv6 | |IPv6| |IPv6| |IPv6|
	| | | | | | | |		| | | | | | | |
	|SCHC C/D and F/R| | | | | | |		|SCHC C/D and F/R| | | | | | |
	+--------+-------+ +----+ +----+ +----+		+--------+-------+ +----+ +----+ +----+
	| +--+ +----+ +----+ +----+ . . .		| +---+ +----+ +----+ +----+ . . .
	+~ |RG| === |NGW | == |SCHC| == |SCHC|...... Internet ....		+~ |RGW| === |NGW | == |SCHC| == |SCHC|...... Internet ....
	+--+ +----+ |F/R | |C/D |		+---+ +----+ |F/R | |C/D |
	+----+ +----+		+----+ +----+
	Figure 1: Architecture		Figure 1: Architecture
	Figure 1 represents the architecture for compression/decompression,		Figure 1 represents the architecture for compression/decompression,
	it is based on [RFC8376] terminology. The Device is sending		it is based on [RFC8376] terminology. The Device is sending
	applications flows using IPv6 or IPv6/UDP protocols. These flow		applications flows using IPv6 or IPv6/UDP protocols. These flow
	might be fragemented (SCHC F/R), and compressed by an Static Context		might be compressed by an Static Context Header Compression
	Header Compression Compressor/Decompressor (SCHC C/D) to reduce		Compressor/Decompressor (SCHC C/D) to reduce headers size and
	headers size. Resulting information is sent on a layer two (L2)		fragmented (SCHC F/R). The resulting information is sent on a layer
	frame to a LPWAN Radio Network (RG) which forwards the frame to a		two (L2) frame to an LPWAN Radio Gateway (RGW) which forwards the
	Network Gateway (NGW). The NGW sends the data to a SCHC F/R for		frame to a Network Gateway (NGW). The NGW sends the data to a SCHC
	defragmentation, if required, then C/D for decompression which shares		F/R for defragmentation, if required, then C/D for decompression
	the same rules with the device. The SCHC F/R and C/D can be located		which shares the same rules with the device. The SCHC F/R and C/D
	on the Network Gateway (NGW) or in another place as long as a tunnel		can be located on the Network Gateway (NGW) or in another place as
	is established between the NGW and the SCHC F/R, then SCHC F/R and		long as a tunnel is established between the NGW and the SCHC F/R,
	SCHC C/D. The SCHC C/D in both sides must share the same set of		then SCHC F/R and SCHC C/D. The SCHC C/D in both sides MUST share
	Rules. After decompression, the packet can be sent on the Internet		the same set of rules. After decompression, the packet can be sent
	to one or several LPWAN Application Servers (App).		on the Internet to one or several LPWAN Application Servers (App).
	The SCHC F/R and SCHC C/D process is bidirectional, so the same		The SCHC F/R and SCHC C/D process is bidirectional, so the same
	principles can be applied in the other direction.		principles can be applied in the other direction.
	In a LoRaWAN network, the RG is called a Gateway, the NGW is Network		In a LoRaWAN network, the RG is called a Gateway, the NGW is Network
	Server, and the SCHC C/D is an Application Server. It can be		Server, and the SCHC C/D is an Application Server. It can be
	provided by the Network Server or any third party software. Figure 1		provided by the Network Server or any third party software. Figure 1
	can be map in LoRaWAN terminology to:		can be mapped in LoRaWAN terminology to:
	Dev App		Dev App
	+----------------+ +----+ +----+ +----+		+--------------+ +----+ +----+ +----+
	| App1 App2 App3 | |App1| |App2| |App3|		|App1 App2 App3| |App1| |App2| |App3|
	| | | | | | | |		| | | | | | | |
	| UDP | |UDP | |UDP | |UDP |		| UDP | |UDP | |UDP | |UDP |
	| IPv6 | |IPv6| |IPv6| |IPv6|		| IPv6 | |IPv6| |IPv6| |IPv6|
	| | | | | | | |		| | | | | | | |
	|SCHC C/D and F/R| | | | | | |		|SCHC C/D & F/R| | | | | | |
	+--------+-------+ +----+ +----+ +----+		+-------+------+ +----+ +----+ +----+
	| +-------+ +-------+ +----------------+ . . .		| +-------+ +-------+ +-----------+ . . .
	+~ |Gateway| === |Network| == |Application |...... Internet ....		+~ |Gateway| === |Network| == |Application|..... Internet ....
	+-------+ |server | |server F/R - C/D|		+-------+ |server | |server |
	+-------+ +----------------+		+-------+ | F/R - C/D |
			+-----------+
	Figure 2: Architecture		Figure 2: SCHC Architecture mapped to LoRaWAN
	4. LoRaWAN Architecture		4. LoRaWAN Architecture
	An overview of LoRaWAN [lora-alliance-spec] protocol and architecture		An overview of LoRaWAN [lora-alliance-spec] protocol and architecture
	is described in [RFC8376]. Mapping between the LPWAN architecture		is described in [RFC8376]. The mapping between the LPWAN
	entities as described in [I-D.ietf-lpwan-ipv6-static-context-hc] and		architecture entities as described in
	the ones in [lora-alliance-spec] is as follows:		[I-D.ietf-lpwan-ipv6-static-context-hc] and the ones in
			[lora-alliance-spec] is as follows:
	o Devices (Dev) are the end-devices or hosts (e.g. sensors,		o Devices (Dev) are the end-devices or hosts (e.g. sensors,
	actuators, etc.). There can be a very high density of devices per		actuators, etc.). There can be a very high density of devices per
	radio gateway (LoRaWAN gateway). This entity maps to the LoRaWAN		radio gateway (LoRaWAN gateway). This entity maps to the LoRaWAN
	End-Device.		End-Device.
	o The Radio Gateway (RGW), which is the end point of the constrained		o The Radio Gateway (RGW), which is the endpoint of the constrained
	link. This entity maps to the LoRaWAN Gateway.		link. This entity maps to the LoRaWAN Gateway.
	o The Network Gateway (NGW) is the interconnection node between the		o The Network Gateway (NGW) is the interconnection node between the
	Radio Gateway and the Internet. This entity maps to the LoRaWAN		Radio Gateway and the Internet. This entity maps to the LoRaWAN
	Network Server.		Network Server.
	o LPWAN-AAA Server, which controls the user authentication and the		o LPWAN-AAA Server, which controls the user authentication and the
	applications. This entity maps to the LoRaWAN Join Server.		applications. This entity maps to the LoRaWAN Join Server.
	o Application Server (App). The same terminology is used in LoRaWAN.		o Application Server (App). The same terminology is used in LoRaWAN.
	skipping to change at page 6, line 29 ¶		skipping to change at page 6, line 29 ¶
	single IP hop, the ultimate end-point of the IP communication may be		single IP hop, the ultimate end-point of the IP communication may be
	an Internet node beyond the Application Server. In other words, the		an Internet node beyond the Application Server. In other words, the
	LoRaWAN Application Server (SCHC gateway) acts as the first hop IP		LoRaWAN Application Server (SCHC gateway) acts as the first hop IP
	router for the End-Device. The Application Server and Network Server		router for the End-Device. The Application Server and Network Server
	may be co-located, which effectively turns the Network/Application		may be co-located, which effectively turns the Network/Application
	Server into the first hop IP router.		Server into the first hop IP router.
	4.1. End-Device classes (A, B, C) and interactions		4.1. End-Device classes (A, B, C) and interactions
	The LoRaWAN MAC layer supports 3 classes of end-devices named A, B		The LoRaWAN MAC layer supports 3 classes of end-devices named A, B
	and C. All end-devices implement the classA, some end-devices		and C. All end-devices implement the Class A, some end-devices may
	implement classA+B or class A+C. ClassB and classC are mutually		implement Class B or Class C. Class B and Class C are mutually
	exclusive.		exclusive.
	o *ClassA*: The classA is the simplest class of end-devices. The		o Class A: The Class A is the simplest class of end-devices. The
	end-device is allowed to transmit at any time, randomly selecting		end-device is allowed to transmit at any time, randomly selecting
	a communication channel. The network may reply with a downlink in		a communication channel. The network may reply with a downlink in
	one of the 2 receive windows immediately following the uplinks.		one of the 2 receive windows immediately following the uplinks.
	Therefore, the network cannot initiate a downlink, it has to wait		Therefore, the network cannot initiate a downlink, it has to wait
	for the next uplink from the end-device to get a downlink		for the next uplink from the end-device to get a downlink
	opportunity. The classA is the lowest power end-device class.		opportunity. The Class A is the lowest power end-device class.
	o *ClassB*: classB end-devices implement all the functionalities of		o Class B: Class B end-devices implement all the functionalities of
	classA end-devices, but also schedule periodic listen windows.		Class A end-devices, but also schedule periodic listen windows.
	Therefore, as opposed the classA end-devices, classB end-devices		Therefore, opposed to the Class A end-devices, Class B end-devices
	can receive downlink that are initiated by the network and not		can receive downlinks that are initiated by the network and not
	following an uplink. There is a trade-off between the periodicity		following an uplink. There is a trade-off between the periodicity
	of those scheduled classB listen windows and the power consumption		of those scheduled Class B listen windows and the power
	of the end-device. The lower the downlink latency, the higher the		consumption of the end-device. The lower the downlink latency,
	power consumption.		the higher the power consumption.
	o *ClassC*: classC end-devices implement all the functionalities of		o Class C: Class C end-devices implement all the functionalities of
	classA end-devices, but keep their receiver open whenever they are		Class A end-devices, but keep their receiver open whenever they
	not transmitting. ClassC end-devices can receive downlinks at any		are not transmitting. Class C end-devices can receive downlinks
	time at the expense of a higher power consumption. Battery		at any time at the expense of a higher power consumption.
	powered end-devices can only operate in classC for a limited		Battery-powered end-devices can only operate in Class C for a
	amount of time (for example for a firmware upgrade over-the-air).		limited amount of time (for example for a firmware upgrade over-
	Most of the classC end-devices are main powered (for example Smart		the-air). Most of the Class C end-devices are grid powered (for
	Plugs).		example Smart Plugs).
	4.2. End-Device addressing		4.2. End-Device addressing
	LoRaWAN end-devices use a 32 bits network address (devAddr) to		LoRaWAN end-devices use a 32-bit network address (devAddr) to
	communicate with the network over-the-air. However, that address		communicate with the network over-the-air. However, that address
	might be reused several time on the same network at the same time for		might be reused several times on the same network at the same time
	different end-devices. End-devices using the same devAddr are		for different end-devices. End-devices using the same devAddr are
	distinguish by the Network Server based on the cryptographic		distinguished by the Network Server based on the cryptographic
	signature appended to every single LoRaWAN MAC frame, as all end-		signature appended to every single LoRaWAN MAC frame, as all end-
	devices use different security keys. To communicate with the SCHC		devices use different security keys. To communicate with the SCHC
	gateway the Network Server MUST identify the end-devices by a unique		gateway the Network Server MUST identify the end-devices by a unique
	64bits device ID called the devEUI. Unlike devAddr, devEUI is		64-bit device identifier called the devEUI. Unlike devAddr, devEUI
	guaranteed to be unique for every single end-device across all		is guaranteed to be unique for every single end-device across all
	networks. The devEUI is assigned to the end-device during the		networks. The devEUI is assigned to the end-device during the
	manufacturing process by the end-device's manufacturer. It is built		manufacturing process by the end-device's manufacturer. It is built
	like an Ethernet MAC address by concatenating the manufacturer's IEEE		like an Ethernet MAC address by concatenating the manufacturer's IEEE
	OUI field with a vendor unique number. ex: 24bits OUI is		OUI field with a vendor unique number. e.g.: 24-bit OUI is
	concatenated with a 40 bits serial number. The Network Server		concatenated with a 40-bit serial number. The Network Server
	translates the devAddr into a devEUI in the uplink direction and		translates the devAddr into a devEUI in the uplink direction and
	reciprocally on the downlink direction.		reciprocally on the downlink direction.
	+--------+ +----------+ +---------+ +----------+		+--------+ +----------+ +---------+ +----------+
	| End- | <=====> | Network | <====> | SCHC | <========> | Internet |		| End- | <=====> | Network | <====> | SCHC | <========> | Internet |
	| Device | devAddr | Server | devEUI | Gateway | IPv6/UDP | |		| Device | devAddr | Server | devEUI | Gateway | IPv6/UDP | |
	+--------+ +----------+ +---------+ +----------+		+--------+ +----------+ +---------+ +----------+
	Figure 4: LoRaWAN addresses		Figure 4: LoRaWAN addresses
	4.3. General Message Types		4.3. General Message Types
	o *Confirmed messages*: The sender asks the receiver to acknowledge		o Confirmed messages: The sender asks the receiver to acknowledge
	the message.		the message.
	o *Unconfirmed messages*: The sender does not ask the receiver to		o Unconfirmed messages: The sender does not ask the receiver to
	acknowledge the message.		acknowledge the message.
	As SCHC defines its own acknowledgment mechanisms, SCHC does not		As SCHC defines its own acknowledgment mechanisms, SCHC does not
	require to use confirmed messages.		require to use confirmed messages.
	4.4. LoRaWAN MAC Frames		4.4. LoRaWAN MAC Frames
	o *JoinRequest*: This message is used by a end-device to join a		o JoinRequest: This message is used by an end-device to join a
	network. It contains the end-device's unique identifier devEUI		network. It contains the end-device's unique identifier devEUI
	and a random nonce that will be used for session key derivation.		and a random nonce that will be used for session key derivation.
	o *JoinAccept*: To on-board a end-device, the Network Server		o JoinAccept: To on-board an end-device, the Network Server responds
	responds to the JoinRequest end-device's message with a JoinAccept		to the JoinRequest end-device's message with a JoinAccept message.
	message. That message is encrypted with the end-device's AppKey		That message is encrypted with the end-device's AppKey and
	and contains (amongst other fields) the major network's settings		contains (amongst other fields) the major network's settings and a
	and a network random nonce used to derive the session keys.		network random nonce used to derive the session keys.
	o *Data*		o Data
	5. SCHC-over-LoRaWAN		5. SCHC-over-LoRaWAN
	5.1. LoRaWAN FPort		5.1. LoRaWAN FPort
	The LoRaWAN MAC layers features a frame port field in all frames.		The LoRaWAN MAC layer features a frame port field in all frames.
	This field (FPort) is 8-bit long and the values from 1 to 223 can be		This field (FPort) is 8-bit long and the values from 1 to 223 can be
	used. It allows LoRaWAN network and application to identify data.		used. It allows LoRaWAN networks and applications to identify data.
			The FPort field is part of the SCHC Packet or the SCHC Fragment, as
			shown in Figure 5. The SCHC C/D and the SCHC F/R SHALL concatenate
			the FPort field with the LoRaWAN payload to retrieve their payload as
			it is used as a part of the ruleId field.
			| FPort | LoRaWAN payload |
			+ ------------------------ +
			| SCHC payload |
			Figure 5: SCHC payload in LoRaWAN
	A fragmentation session with application payload transferred from		A fragmentation session with application payload transferred from
	device to server, is called uplink fragmentation session. It uses		device to server, is called uplink fragmentation session. It uses an
	FPortUpShort or FPortUpDefault for data uplink and its associated		FPort for data uplink and its associated SCHC control downlinks,
	SCHC control downlinks. The other way, a fragmentation session with		named FPortUp in this document. The other way, a fragmentation
	application payload transferred from server to device, is called		session with application payload transferred from server to device,
	downlink fragmentation session. It uses FPortDown for data downlink		is called downlink fragmentation session. It uses another FPort for
	and its associated SCHC control uplinks.		data downlink and its associated SCHC control uplinks, named
			FPortDown in this document.
	FPorts can use arbitrary values inside the allowed FPort range and		FPorts can use arbitrary values inside the allowed FPort range and
	must be shared by the end-device, the Network Server and SCHC		MUST be shared by the end-device, the Network Server and SCHC gateway
	gateway. The uplink and downlink SCHC ports must be different. In		prior to the communication. The uplink and downlink fragmentation
	order to improve interoperability, it is recommended to use:		FPorts MUST be different.
	o FPortUpShort = 20		5.2. Rule ID management
	o FPortUpDefault = 21		RuleID minimum length MUST be 8 bits, and RECOMMENDED length is 8
			bits. RuleID MSB is encoded in the LoRaWAN FPort as described in
			Section 5.1. LoRaWAN supports up to 223 application FPorts in the
			range [1;223] as defined in section 4.3.2 of [lora-alliance-spec], it
			implies that RuleID MSB SHOULD be inside this range. An application
			MAY reserve some FPort values for other needs as long as they don't
			conflict with FPorts used for SCHC C/D and SCHC F/R.
	o FPortDown = 22		A RuleID SHOULD be reserved to tag packets for which SCHC compression
			was not possible (no matching Rule was found). RuleIDs FPortUp and
			FPortDown are reserved for fragmentation, in order to improve
			interoperability RECOMMENDED values are:
	Those are recommended values and are application defined. Also		o RuleID = 20 (8-bit) for uplink fragmentation, named FPortUp
	application can have multiple fragmentation session between a device
	and one or several SCHC gateways. A set of three FPort values is		o RuleID = 21 (8-bit) for downlink fragmentation, named FPortDown
	required for each gateway instance the device is required to
	communicate with.		o RuleID = 22 (8-bit) for which SCHC compression was not possible
			The remaining RuleIDs are available for compression. RuleIDs are
			shared between uplink and downlink sessions. A RuleID different from
			FPortUp or FPortDown means that the fragmentation is not used, thus
			the packet SHOULD be sent to C/D layer.
	The only uplink messages using the FPortDown port are the		The only uplink messages using the FPortDown port are the
	fragmentation SCHC control messages of a downlink fragmentation		fragmentation SCHC control messages of a downlink fragmentation
	session (ex ACKs). Similarly, the only downlink messages using the		session (ex ACKs). Similarly, the only downlink messages using the
	FPortUpShort or FPortUpDefault ports are the fragmentation SCHC		FPortUp port are the fragmentation SCHC control messages of an uplink
	control messages of an uplink fragmentation session.		fragmentation session.
	5.2. Rule ID management
	SCHC-over-LoRaWAN SHOULD support encoding RuleID on 6 bits (64
	possible rules).
	The RuleID 0 is reserved for fragmentation. The RuleID 63 is used to		An application can have multiple fragmentation sessions between a
	tag packets for which SCHC compression was not possible (no matching		device and one or several SCHC gateways. A set of FPort values is
	Rule was found).		REQUIRED for each SCHC gateway instance the device is required to
			communicate with.
	The remaining RuleIDs are available for compression. RuleIDs are		The mechanism for sharing those RuleID values is outside the scope of
	shared between uplink and downlink sessions. A RuleID different from		this document.
	0 means that the fragmentation is not used, thus the packet should be
	send to C/D layer.
	5.3. IID computation		5.3. IID computation
	As LoRaWAN network uses unique EUI-64 per end-device, the Interface		As LoRaWAN network uses unique EUI-64 per end-device, the Interface
	IDentifier is the LoRaWAN DevEUI. It is compliant with [RFC4291] and		IDentifier is the LoRaWAN DevEUI. It is compliant with [RFC4291] and
	IID starting with binary 000 must enforce the 64-bits rule. TODO:		IID starting with binary 000 must enforce the 64-bit rule.
	Derive IID from DevEUI with privacy constraints ? Ask working group ?
	5.4. Fragmentation		TODO: Derive IID from DevEUI with privacy constraints ? Ask working
			group ?
			5.4. Padding
			All padding bits MUST be 0.
			5.5. Compression
			SCHC C/D MUST concatenate FPort and LoRaWAN payload to retrieve the
			SCHC packet as per Section 5.1.
			SCHC C/D RuleID size SHOULD be 8 bits to fit the LoRaWAN FPort field.
			RuleIDs matching FPortUp and FPortDown are reserved for SCHC
			Fragmentation.
			5.6. Fragmentation
	The L2 word size used by LoRaWAN is 1 byte (8 bits). The SCHC		The L2 word size used by LoRaWAN is 1 byte (8 bits). The SCHC
	fragmentation over LoRaWAN uses the ACK-on-Error for uplink		fragmentation over LoRaWAN uses the ACK-on-Error for uplink
	fragmentation and Ack-Always for downlink fragmentation. A LoRaWAN		fragmentation and Ack-Always for downlink fragmentation. A LoRaWAN
	end-device cannot support simultaneous interleaved fragmentation		end-device cannot support simultaneous interleaved fragmentation
	sessions in the same direction (uplink or downlink). This means that		sessions in the same direction (uplink or downlink). This means that
	only a single fragmented IPv6 datagram may be transmitted and/or		only a single fragmented IPv6 datagram may be transmitted and/or
	received by the end-device at a given moment.		received by the end-device at a given moment.
	The fragmentation parameters are different for uplink and downlink		The fragmentation parameters are different for uplink and downlink
	fragmentation sessions and are successively described in the next		fragmentation sessions and are successively described in the next
	sections.		sections.
	5.5. DTag		5.6.1. DTag
	A LoRaWAN device cannot interleave several fragmented SCHC datagrams.		A LoRaWAN device cannot interleave several fragmented SCHC datagrams
	This one bit field is used to distinguish two consecutive		on the same FPort. This field is not used and its size is 0.
	fragmentation sessions.
	_Note_: While it is used to recover faster from transmission errors,		Note: The device can still have several parallel fragmentation
	it SHALL not be considered as the only way to distinguish two		sessions with one or more SCHC gateway(s) thanks to distinct sets of
	fragmentation sessions.		FPorts, cf Section 5.2
	5.5.1. Uplink fragmentation: From device to SCHC gateway		5.6.2. Uplink fragmentation: From device to SCHC gateway
	In that case the device is the fragmentation transmitter, and the		In that case the device is the fragmentation transmitter, and the
	SCHC gateway the fragmentation receiver. Two fragmentation rules are		SCHC gateway the fragmentation receiver. A single fragmentation rule
	defined regarding the *FPort*:		is defined. SCHC F/R MUST concatenate FPort and LoRaWAN payload to
			retrieve the SCHC fragment as per Section 5.1.
	o *FPortUpShort*: SCHC header is only one byte. Used when		o Minimum SCHC header is two bytes (the FPort byte + 1 additional
	fragmentation is required and payload size is less than 381 bytes.		byte) and the RECOMMENDED header size is two bytes.
	o *FPortUpDefault*: SCHC header is two bytes. Used for all other		o RuleID: Recommended size is 8 bits in SCHC header.
	cases: no fragmentation required or payload size is between 382
	and 1524 byte.
	*Both rules share common parameters:*		o SCHC fragmentation reliability mode: "ACK-on-Error"
	o *SCHC fragmentation reliability mode*: "ACK-on-Error"		o DTag: Size is 0 bit, not used
	o *DTag*: size is 1 bit.		o FCN: The FCN field is encoded on N = 6 bits, so WINDOW_SIZE = 64
			tiles are allowed in a window
	o *FCN*: The FCN field is encoded on N = 7 bits, so WINDOW_SIZE =		o Window index: encoded on W = 2 bits. So 4 windows are available.
	127 tiles are allowed in a window (FCN=All-1 is reserved for
	SCHC).
	o *MIC calculation algorithm*: CRC32 using 0xEDB88320 (i.e. the		o RCS calculation algorithm: CRC32 using 0xEDB88320 (i.e. the
	reverse representation of the polynomial used e.g. in the Ethernet		reverse representation of the polynomial used e.g. in the Ethernet
	standard [RFC3385]) as suggested in		standard [RFC3385]) as suggested in
	[I-D.ietf-lpwan-ipv6-static-context-hc].		[I-D.ietf-lpwan-ipv6-static-context-hc].
	o *MAX_ACK_REQUESTS*: 8		o MAX_ACK_REQUESTS: 8
	o *Tile*: size is 3 bytes (24 bits)		o Tile: size is 5 bytes
	o *Retransmission and inactivity timers*: LoRaWAN end-devices do not		o Retransmission and inactivity timers: LoRaWAN end-devices do not
	implement a "retransmission timer". At the end of a window or a		implement a "retransmission timer". At the end of a window or a
	fragmentation session, corresponding ACK(s) is (are) transmitted		fragmentation session, corresponding ACK(s) is (are) transmitted
	by the network gateway (LoRaWAN application server) in the RX1 or		by the network gateway (LoRaWAN application server) in the RX1 or
	RX2 receive slot of end-device. If this ACK is not received the		RX2 receive slot of end-device. If this ACK is not received by
	end-device sends an all-0 (or an all-1) fragment with no payload		the end-device at the end of its RX windows, it sends an all-0 (or
	to request an SCHC ACK retransmission. The periodicity between		an all-1) fragment with no payload to request an SCHC ACK
	retransmission of the all-0/all-1 fragments is device/application		retransmission. The periodicity between retransmission of the
	specific and may be different for each device (not specified).		all-0/all-1 fragments is device/application specific and MAY be
	The SCHC gateway implements an "inactivity timer". The default		different for each device (not specified). The SCHC gateway
	recommended duration of this timer is 12 hours. This value is		implements an "inactivity timer". The default RECOMMENDED
	mainly driven by application requirements and may be changed by		duration of this timer is 12 hours. This value is mainly driven
	the application.		by application requirements and MAY be changed by the application.
	*The following fields are different:*
	o RuleID size
	o Window index size W
	5.5.1.1. FPortUpShort - 1 byte header
	In that case RuleID size is 0, the rule is the FPort=FPortUpShort and
	only fragmented payload can be transported.
	o *RuleID*: size is 0 bit in SCHC header, not used.
	o *Window index*: encoded on W = 0 bit, not used
	With this set of parameters, the SCHC fragment header overhead is 1
	byte (8 bits). MTU is: _127 tiles * 3 bytes per tile = 381 bytes_
	*Regular fragments*
	| DTag | FCN | Payload |
	+ ----- + ------ + ------- +
	| 1 bit | 7 bits | |
	Figure 5: All fragment except the last one. Header size is 8 bits (1
	byte).
	*SCHC ACK*
	| DTag | C | Encoded bitmap (if C = 0) | Padding (0s) |
	+ ----- + ----- + ------------------------- + ------------ +
	| 1 bit | 1 bit | 0 to 127 bits | 7 or 0 bits |
	Figure 6: SCHC ACK format, failed mic check.
	5.5.1.2. FPortUpDefault - 2 bytes header
	o *RuleID*: size is 6 bits (64 possible rules, 62 available for
	compression)
	o *Window index*: encoded on W = 2 bits. So 4 windows are
	available.
	With this set of parameters, the SCHC fragment header overhead is 2		o Last tile: The last tile can be carried in the All-1 fragment.
	bytes (16 bits). MTU is: _4 windows * 127 tiles * 3 bytes per tile =
	1524 bytes_
	_Note_: Even if it is less efficient, this rule can also be used for		With this set of parameters, the SCHC fragment header is 16 bits,
	fragmented payload size less than 382 bytes.		including FPort; payload overhead will be 8 bits as FPort is already
			a part of LoRaWAN payload. MTU is: _4 windows * 64 tiles * 5 bytes
			per tile = 1280 bytes_
	*Regular fragments*		5.6.2.1. Regular fragments
			| FPort | LoRaWAN payload |
			+ ------ + ------------------------- +
			| RuleID | W | FCN | Payload |
			+ ------ + ------ + ------ + ------- +
			| 8 bits | 2 bits | 6 bits | |
	| RuleID | DTag | W | FCN | Payload |		Figure 6: All fragments except the last one. SCHC header size is 16
	+ ------ + ----- + ------ + ------ + ------- +		bits, including LoRaWAN FPort.
	| 6 bits | 1 bit | 2 bits | 7 bits | |
	Figure 7: All fragment except the last one. Header size is 16 bits		5.6.2.2. Last fragment (All-1)
	(2 bytes).
	*Last fragment (All-1)*		| FPort | LoRaWAN payload |
			+ ------ + ------------------------------------------------ +
			| RuleID | W | FCN=All-1 | RCS | Payload |
			+ ------ + ------ + --------- + ------- + ----------------- +
			| 8 bits | 2 bits | 6 bits | 32 bits | Last tile, if any |
	| RuleID | DTag | W | FCN=All-1 | MIC | Payload |		Figure 7: All-1 fragment detailed format for the last fragment.
	+ ------ + ----- + ------ + --------- + ------- + ----------------- +
	| 6 bits | 1 bit | 2 bits | 7 bits | 32 bits | Last tile, if any |
	Figure 8: All-1 fragment detailed format for the last fragment.		5.6.2.3. SCHC ACK
	*SCHC ACK*		| FPort | LoRaWAN payload |
			+ ------ + ----------------------------------------- +
			| RuleID | W | C | Encoded bitmap (if C = 0) |
			+ ------ + ----- + ----- + ------------------------- +
			| 8 bits | 2 bit | 1 bit | 0 to 127 bits |
	| RuleID | DTag | W | C | Encoded bitmap (if C = 0) |		Figure 8: SCHC formats, failed RCS check.
	+ ------ + ----- + ----- + ----- + ------------------------- +
	| 6 bits | 1 bit | 2 bit | 1 bit | 0 to 127 bits |
	Figure 9: SCHC formats, failed MIC check.		5.6.2.4. Receiver-Abort
	*Receiver-Abort*		| FPort | LoRaWAN payload |
			+ ------ + -------------------------------------------- +
			| RuleID | W = b'11 | C = 1 | b'11111 | 0xFF (all 1's) |
			+ ------ + -------- + ------+-------- + ----------------+
			| 8 bits | 2 bits | 1 bit | 5 bits | 8 bits |
			next L2 Word boundary ->| <-- L2 Word --> |
	| RuleID | DTag | W = b'11 | C = 1 | b'111111 | 0xFF (all 1's) |		Figure 9: Receiver-Abort format.
	+ ------ + ----- + -------- + ------+--------- + ---------------+
	| 6 bits | 1 bit | 2 bits | 1 bit | 6 bits | 8 bits |
	Figure 10: Receiver-Abort format.		5.6.2.5. SCHC acknowledge request
	*SCHC acknowledge request*		| FPort | LoRaWAN payload |
	| RuleID | DTag | W | FCN = b'0000000 |		+------- +------------------------- +
	+ ------ + ----- + ------ + --------------- +		| RuleID | W | FCN = b'000000 |
	| 6 bits | 1 bit | 2 bits | 7 bits |		+ ------ + ------ + --------------- +
			| 8 bits | 2 bits | 6 bits |
	Figure 11: SCHC ACK REQ format.		Figure 10: SCHC ACK REQ format.
	5.5.2. Downlink fragmentation: From SCHC gateway to device		5.6.3. Downlink fragmentation: From SCHC gateway to a device
	In that case the device is the fragmentation receiver, and the SCHC		In that case the device is the fragmentation receiver, and the SCHC
	gateway the fragmentation transmitter. The following fields are		gateway the fragmentation transmitter. The following fields are
	common to all devices.		common to all devices. SCHC F/R MUST concatenate FPort and LoRaWAN
			payload to retrieve the SCHC fragment as described in Section 5.1.
	o *SCHC fragmentation reliability mode*: ACK-Always.		o SCHC fragmentation reliability mode: ACK-Always.
	o *RuleID*: size is 6 bits (64 possible rules, 62 for compression).		o RuleID: Recommended size is 8 bits in SCHC header.
	o *Window index*: encoded on W=1 bit, as per		o Window index: encoded on W=1 bit, as per
	[I-D.ietf-lpwan-ipv6-static-context-hc].		[I-D.ietf-lpwan-ipv6-static-context-hc].
	o *DTag*: Not used, so its size is 0 bit.		o DTag: Size is 0 bit, not used
	o *FCN*: The FCN field is encoded on N=1 bits, so WINDOW_SIZE = 1		o FCN: The FCN field is encoded on N=1 bit, so WINDOW_SIZE = 1 tile
	tile (FCN=All-1 is reserved for SCHC).		(FCN=All-1 is reserved for SCHC).
	o *MIC calculation algorithm*: CRC32 using 0xEDB88320 (i.e. the		o RCS calculation algorithm: CRC32 using 0xEDB88320 (i.e. the
	reverse representation of the polynomial used e.g. in the Ethernet		reverse representation of the polynomial used e.g. in the Ethernet
	standard [RFC3385]), as per		standard [RFC3385]), as per
	[I-D.ietf-lpwan-ipv6-static-context-hc].		[I-D.ietf-lpwan-ipv6-static-context-hc].
	o *MAX_ACK_REQUESTS*: 8		o MAX_ACK_REQUESTS: 8
	As only 1 tile is used, its size can change for each downlink, and		As only 1 tile is used, its size can change for each downlink, and
	will be maximum available MTU minus header (1 byte)		will be maximum available MTU.
	_Note_: The Fpending bit included in LoRaWAN protocol SHOULD not be		_Note_: The Fpending bit included in LoRaWAN protocol SHOULD NOT be
	used for SCHC-over-LoRaWAN protocol. It might be set by the Network		used for SCHC-over-LoRaWAN protocol. It might be set by the Network
	Server for other purposes in but not SCHC needs.		Server for other purposes but not SCHC needs.
	*Regular fragments*		5.6.3.1. Regular fragments
	| RuleID | W | FCN = b'0 | Payload |
	+ ------ + ----- + --------- + ------- +
	| 6 bits | 1 bit | 1 bits | X bytes |
	Figure 12: All fragments but the last one. Header size 1 byte (8		| FPort | LoRaWAN payload |
	bits).		+ ------ + ----------------------------------- +
			| RuleID | W | FCN = b'0 | Payload |
			+ ------ + ----- + --------- + --------------- +
			| 8 bits | 1 bit | 1 bit | X bytes |
	*Last fragment (All-1)*		Figure 11: All fragments but the last one. Header size 10 bits,
			including LoraWAN FPort.
	| RuleID | W | FCN = b'1 | MIC | Payload |		5.6.3.2. Last fragment (All-1)
			| FPort | LoRaWAN payload |
			+ ------ + ----------------------------------------------- +
			| RuleID | W | FCN = b'1 | RCS | Payload |
	+ ------ + ----- + --------- + ------- + ----------------- +		+ ------ + ----- + --------- + ------- + ----------------- +
	| 6 bits | 1 bit | 1 bit | 32 bits | Last tile, if any |		| 8 bits | 1 bit | 1 bit | 32 bits | Last tile, if any |
	Figure 13: All-1 SCHC ACK detailed format for the last fragment.		Figure 12: All-1 SCHC ACK detailed format for the last fragment.
	*SCHC acknowledge*		5.6.3.3. SCHC acknowledge
	| RuleID | W | C = b'1 |		| FPort | LoRaWAN payload |
	+ ------ + ----- + ------- +		+ ------ + ---------------------------------- +
	| 6 bits | 1 bit | 1 bit |		| RuleID | W | C = b'1 | Padding b'000000 |
			+ ------ + ----- + ------- + ---------------- +
			| 8 bits | 1 bit | 1 bit | 6 bits |
	Figure 14: SCHC ACK format, MIC is correct.		Figure 13: SCHC ACK format, RCS is correct.
	*Receiver-Abort*		5.6.3.4. Receiver-Abort
	| RuleID | W | C = b'0 | b'11111111 |		| FPort | LoRaWAN payload |
	+ ------ + ----- + ------- + ---------- +		+ ------ + ---------------------------------------------- +
	| 6 bits | 1 bit | 1 bits | 8 bits |		| RuleID | W = b'1 | C = b'1 | b'111111 | 0xFF (all 1's) |
			+ ------ + ------- + ------- + -------- + --------------- +
			| 8 bits | 1 bit | 1 bits | 6 bits | 8 bits |
			next L2 Word boundary ->| <-- L2 Word --> |
	Figure 15: Receiver-Abort packet (following an all-1 packet with		Figure 14: Receiver-Abort packet (following an all-1 packet with
	incorrect MIC).		incorrect RCS).
	Class A and classB&C end-devices do not manage retransmissions and		Class A and Class B or Class C end-devices do not manage
	timers in the same way.		retransmissions and timers in the same way.
	5.5.2.1. ClassA end-devices		5.6.3.5. Class A end-devices
	Class A end-devices can only receive in an RX slot following the		Class A end-devices can only receive in an RX slot following the
	transmission of an uplink. Therefore there cannot be a concept of		transmission of an uplink. Therefore there cannot be a concept of
	"retransmission timer" for an SCHC gateway. The SCHC gateway cannot		"retransmission timer" for an SCHC gateway. The SCHC gateway cannot
	initiate communication to a classA end-device.		initiate communication to a Class A end-device.
	The device replies with an ACK message to every single fragment		The device replies with an ACK message to every single fragment
	received from the SCHC gateway (because the window size is 1).		received from the SCHC gateway (because the window size is 1).
	Following the reception of a FCN=0 fragment (fragment that is not the		Following the reception of a FCN=0 fragment (fragment that is not the
	last fragment of the packet or ACK-request, but the end of a window),		last fragment of the packet or ACK-request, but the end of a window),
	the device MUST transmit the SCHC ACK fragment until it receives the		the device MUST transmit the SCHC ACK fragment until it receives the
	fragment of the next window. The device shall transmit up to		fragment of the next window. The device SHALL transmit up to
	MAX_ACK_REQUESTS ACK messages before aborting. The device should		MAX_ACK_REQUESTS ACK messages before aborting. The device should
	transmit those ACK as soon as possible while taking into		transmit those ACK as soon as possible while taking into
	consideration potential local radio regulation on duty-cycle, to		consideration potential local radio regulation on duty-cycle, to
	progress the fragmentation session as quickly as possible. The ACK		progress the fragmentation session as quickly as possible. The ACK
	bitmap is 1 bit long and is always 1.		bitmap is 1 bit long and is always 1.
	Following the reception of a FCN=All-1 fragment (the last fragment of		Following the reception of an FCN=All-1 fragment (the last fragment
	a datagram) and if the MIC is correct, the device shall transmit the		of a datagram) and if the RCS is correct, the device SHALL transmit
	ACK with the "MIC is correct" indicator bit set (C=1). This message		the ACK with the "RCS is correct" indicator bit set (C=1). This
	might be lost therefore the SCHC gateway may request a retransmission		message might be lost therefore the SCHC gateway MAY request a
	of this ACK in the next downlink. The device SHALL keep this ACK		retransmission of this ACK in the next downlink. The device SHALL
	message in memory until it receives a downlink, on SCHC FPortDown		keep this ACK message in memory until it receives a downlink, on SCHC
	from the SCHC gateway different from an ACK-request: it indicates		FPortDown from the SCHC gateway different from an ACK-request: it
	that the SCHC gateway has received the ACK message.		indicates that the SCHC gateway has received the ACK message.
	Following the reception of a FCN=All-1 fragment (the last fragment of		Following the reception of a FCN=All-1 fragment (the last fragment of
	a datagram), if all fragments have been received and the MIC is NOT		a datagram), if all fragments have been received and the RCS is not
	correct, the device shall transmit a Receiver-Abort fragment. The		correct, the device SHALL transmit a Receiver-Abort fragment. The
	device SHALL keep this Abort message in memory until it receives a		device SHALL keep this Abort message in memory until it receives a
	downlink, on SCHC FPortDown, from the SCHC gateway different from an		downlink, on SCHC FPortDown, from the SCHC gateway different from an
	ACK-request indicating that the SCHC gateway has received the Abort		ACK-request indicating that the SCHC gateway has received the Abort
	message. The fragmentation receiver (device) does not implement		message. The fragmentation receiver (device) does not implement
	retransmission timer and inactivity timer.		retransmission timer and inactivity timer.
	The fragmentation sender (the SCHC gateway) implements an inactivity		The fragmentation sender (the SCHC gateway) implements an inactivity
	timer with default duration of 12 hours. Once a fragmentation		timer with a default duration of 12 hours. Once a fragmentation
	session is started, if the SCHC gateway has not received any ACK or		session is started, if the SCHC gateway has not received any ACK or
	Receiver-Abort message 12 hours after the last message from the		Receiver-Abort message 12 hours after the last message from the
	device was received, the SCHC gateway may flush the fragmentation		device was received, the SCHC gateway MAY flush the fragmentation
	context. For devices with very low transmission rates (example 1		context. For devices with very low transmission rates (example 1
	packet a day in normal operation) , that duration may be extended,		packet a day in normal operation) , that duration may be extended,
	but this is application specific.		but this is application specific.
	5.5.2.2. Class B or C end-devices		5.6.3.6. Class B or Class C end-devices
	Class B&C end-devices can receive in scheduled RX slots or in RX		Class B and Class C end-devices can receive in scheduled RX slots or
	slots following the transmission of an uplink. The device replies		in RX slots following the transmission of an uplink. The device
	with an ACK message to every single fragment received from the SCHC		replies with an ACK message to every single fragment received from
	gateway (because the window size is 1). Following the reception of a		the SCHC gateway (because the window size is 1). Following the
	FCN=0 fragment (fragment that is not the last fragment of the packet		reception of an FCN=0 fragment (fragment that is not the last
	or ACK-request), the device MUST always transmit the corresponding		fragment of the packet or ACK-request), the device MUST always
	SCHC ACK message even if that fragment has already been received.		transmit the corresponding SCHC ACK message even if that fragment has
	The ACK bitmap is 1 bit long and is always 1. If the SCHC gateway		already been received. The ACK bitmap is 1 bit long and is always 1.
	receives this ACK, it proceeds to send the next window fragment. If		If the SCHC gateway receives this ACK, it proceeds to send the next
	the retransmission timer elapses and the SCHC gateway has not		window fragment. If the retransmission timer elapses and the SCHC
	received the ACK of the current window it retransmits the last		gateway has not received the ACK of the current window it retransmits
	fragment. The SCHC gateway tries retransmitting up to		the last fragment. The SCHC gateway tries retransmitting up to
	MAX_ACK_REQUESTS times before aborting.		MAX_ACK_REQUESTS times before aborting.
	Following the reception of a FCN=All-1 fragment (the last fragment of		Following the reception of an FCN=All-1 fragment (the last fragment
	a datagram) and if the MIC is correct, the device shall transmit the		of a datagram) and if the RCS is correct, the device SHALL transmit
	ACK with the "MIC is correct" indicator bit set. If the SCHC gateway		the ACK with the "RCS is correct" indicator bit set. If the SCHC
	receives this ACK, the current fragmentation session has succeeded		gateway receives this ACK, the current fragmentation session has
	and its context can be cleared.		succeeded and its context can be cleared.
	If the retransmission timer elapses and the SCHC gateway has not		If the retransmission timer elapses and the SCHC gateway has not
	received the SCHC ACK it retransmits the last fragment with the		received the SCHC ACK it retransmits the last fragment with the
	payload (not an ACK-request without payload). The SCHC gateway tries		payload (not an ACK-request without payload). The SCHC gateway tries
	retransmitting up to MAX_ACK_REQUESTS times before aborting.		retransmitting up to MAX_ACK_REQUESTS times before aborting.
	The device SHALL keep the SCHC ACK message in memory until it		Following the reception of an FCN=All-1 fragment (the last fragment
	receives a downlink from the SCHC gateway different from the last		of a datagram), if all fragments have been received and if the RCS is
	(FCN>0 and different DTag) fragment indicating that the SCHC gateway		NOT correct, the device SHALL transmit a Receiver-Abort fragment.
	has received the ACK message.
	Following the reception of a FCN=All-1 fragment (the last fragment of
	a datagram), if all fragments have been received and if the MIC is
	NOT correct, the device shall transmit a Receiver-Abort fragment.
	The retransmission timer is used by the SCHC gateway (the sender),		The retransmission timer is used by the SCHC gateway (the sender),
	the optimal value is very much application specific but here are some		the optimal value is very much application specific but here are some
	recommended default values. For classB end-devices, this timer		recommended default values. For Class B end-devices, this timer
	trigger is a function of the periodicity of the classB ping slots.		trigger is a function of the periodicity of the Class B ping slots.
	The recommended value is equal to 3 times the classB ping slot		The RECOMMENDED value is equal to 3 times the Class B ping slot
	periodicity. For classC end-devices which are nearly constantly		periodicity. For Class C end-devices which are nearly constantly
	receiving, the recommended value is 30 seconds. This means that the		receiving, the RECOMMENDED value is 30 seconds. This means that the
	end-device shall try to transmit the ACK within 30 seconds of the		end-device shall try to transmit the ACK within 30 seconds of the
	reception of each fragment. The inactivity timer is implemented by		reception of each fragment. The inactivity timer is implemented by
	the end-device to flush the context in-case it receives nothing from		the end-device to flush the context in-case it receives nothing from
	the SCHC gateway over an extended period of time. The recommended		the SCHC gateway over an extended period of time. The RECOMMENDED
	value is 12 hours for both classB&C end-devices.		value is 12 hours for both Class B and Class C end-devices.
	6. Security considerations		6. Security considerations
	This document is only providing parameters that are expected to be		This document is only providing parameters that are expected to be
	better suited for LoRaWAN networks for		better suited for LoRaWAN networks for
	[I-D.ietf-lpwan-ipv6-static-context-hc]. As such, this parameters		[I-D.ietf-lpwan-ipv6-static-context-hc]. As such, this document does
	does not contribute to any new security issues in addition of those		not contribute to any new security issues in addition to those
	identified in [I-D.ietf-lpwan-ipv6-static-context-hc].		identified in [I-D.ietf-lpwan-ipv6-static-context-hc].
	Acknowledgements		Acknowledgements
	Thanks to all those listed in the Contributors section for the		Thanks to all those listed in the Contributors section for the
	excellent text, insightful discussions, reviews and suggestions.		excellent text, insightful discussions, reviews and suggestions.
	Contributors		Contributors
	Contributors ordered by family name.		Contributors ordered by family name.
	o ins: V. Audebert name: Vincent AUDEBERT org: EDF R&D street: 7 bd		o ins: V. Audebert name: Vincent AUDEBERT org: EDF R&D street: 7 bd
	Gaspard Monge city: 91120 PALAISEAU country: FRANCE email:		Gaspard Monge city: 91120 PALAISEAU country: FRANCE email:
	vincent.audebert@edf.fr		vincent.audebert@edf.fr
	o ins: J. Catalano name: Julien Catalano org: Kerlink street: 1 rue
	Jacqueline Auriol city: 35235 Thorigne-Fouillard country: France
	email: j.catalano@kerlink.fr
	o ins: M. Coracin name: Michael Coracin org: Semtech street: 14		o ins: M. Coracin name: Michael Coracin org: Semtech street: 14
	Chemin des Clos city: Meylan country: France email:		Chemin des Clos city: Meylan country: France email:
	mcoracin@semtech.com		mcoracin@semtech.com
	o ins: M. Le Gourrierec name: Marc Le Gourrierec org: SagemCom		o ins: M. Le Gourrierec name: Marc Le Gourrierec org: SagemCom
	street: 250 Route de l'Empereur city: 92500 Rueil Malmaison		street: 250 Route de l'Empereur city: 92500 Rueil Malmaison
	country: FRANCE email: marc.legourrierec@sagemcom.com		country: FRANCE email: marc.legourrierec@sagemcom.com
	o ins: N. Sornin name: Nicolas Sornin org: Semtech street: 14		o ins: N. Sornin name: Nicolas Sornin org: Semtech street: 14
	Chemin des Clos city: Meylan country: France email:		Chemin des Clos city: Meylan country: France email:
	skipping to change at page 18, line 23 ¶		skipping to change at page 18, line 23 ¶
	[RFC5795] Sandlund, K., Pelletier, G., and L-E. Jonsson, "The RObust		[RFC5795] Sandlund, K., Pelletier, G., and L-E. Jonsson, "The RObust
	Header Compression (ROHC) Framework", RFC 5795,		Header Compression (ROHC) Framework", RFC 5795,
	DOI 10.17487/RFC5795, March 2010,		DOI 10.17487/RFC5795, March 2010,
	<https://www.rfc-editor.org/info/rfc5795>.		<https://www.rfc-editor.org/info/rfc5795>.
	[RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6		[RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6
	Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136,		Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136,
	February 2014, <https://www.rfc-editor.org/info/rfc7136>.		February 2014, <https://www.rfc-editor.org/info/rfc7136>.
			[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
			2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
			May 2017, <https://www.rfc-editor.org/info/rfc8174>.
	[RFC8376] Farrell, S., Ed., "Low-Power Wide Area Network (LPWAN)		[RFC8376] Farrell, S., Ed., "Low-Power Wide Area Network (LPWAN)
	Overview", RFC 8376, DOI 10.17487/RFC8376, May 2018,		Overview", RFC 8376, DOI 10.17487/RFC8376, May 2018,
	<https://www.rfc-editor.org/info/rfc8376>.		<https://www.rfc-editor.org/info/rfc8376>.
	9.2. Informative References		9.2. Informative References
	[I-D.ietf-lpwan-ipv6-static-context-hc]		[I-D.ietf-lpwan-ipv6-static-context-hc]
	Minaburo, A., Toutain, L., Gomez, C., Barthel, D., and J.		Minaburo, A., Toutain, L., Gomez, C., Barthel, D., and J.
	Zuniga, "Static Context Header Compression (SCHC) and		Zuniga, "Static Context Header Compression (SCHC) and
	fragmentation for LPWAN, application to UDP/IPv6", draft-		fragmentation for LPWAN, application to UDP/IPv6", draft-
	ietf-lpwan-ipv6-static-context-hc-19 (work in progress),		ietf-lpwan-ipv6-static-context-hc-21 (work in progress),
	July 2019.		July 2019.
	[lora-alliance-spec]		[lora-alliance-spec]
	Alliance, L., "LoRaWAN Specification Version V1.0.3",		Alliance, L., "LoRaWAN Specification Version V1.0.3",
	<https://lora-alliance.org/sites/default/files/2018-07/		<https://lora-alliance.org/sites/default/files/2018-07/
	lorawan1.0.3.pdf>.		lorawan1.0.3.pdf>.
	Appendix A. Examples		Appendix A. Examples
	A.1. Uplink - Compression example - No fragmentation		A.1. Uplink - Compression example - No fragmentation
	Figure 16 is representing an applicative payload going through SCHC,		Figure 15 is representing an applicative payload going through SCHC,
	no fragmentation required		no fragmentation required
	An applicative payload of 78 bytes is passed to SCHC compression layer using		An applicative payload of 78 bytes is passed to SCHC compression layer
	rule 1, allowing to compress it to 40 bytes and 5 bits: 21 bits residue + 38 bytes		using rule 1, allowing to compress it to 40 bytes and 5 bits: 1 byte
	payload.		ruleID, 21 bits residue + 37 bytes payload.
	| RuleID | Compression residue | Payload | Padding=0b000 |		| RuleID | Compression residue | Payload | Padding=b'000 |
	+ ------ + ------------------- + --------- + ------------- +		+ ------ + ------------------- + --------- + ------------- +
	| 1 | 21 bits | 38 bytes | 3 bits |		| 1 | 21 bits | 38 bytes | 3 bits |
	The current LoRaWAN MTU is 51 bytes, although 2 bytes FOpts are used by		The current LoRaWAN MTU is 51 bytes, although 2 bytes FOpts are used by
	LoRaWAN protocol: 49 bytes are available for SCHC payload; no need for		LoRaWAN protocol: 49 bytes are available for SCHC payload; no need for
	fragmentation. The payload will be transmitted through FPortUpDefault		fragmentation. The payload will be transmitted through FPort = 1
	| LoRaWAN Header | RuleID | Compression residue | Payload | Padding=b'000 |		| LoRaWAN Header | LoRaWAN payload (40 bytes) |
	+ -------------- + ------ + ------------------- + --------- + ------------- +		+ ------------------------- + --------------------------------------- +
	| XXXX | 1 | 21 bits | 38 bytes | 3 bits |		| | FOpts | RuleID=1 | Compression | Payload | Padding=b'000 |
			| | | | residue | | |
			+ ---- + ------- + -------- + ----------- + --------- + ------------- +
			| XXXX | 2 bytes | 1 byte | 21 bits | 37 bytes | 3 bits |
	Figure 16: Uplink example: compression without fragmentation		Figure 15: Uplink example: compression without fragmentation
	A.2. Uplink - Compression and fragmentation example		A.2. Uplink - Compression and fragmentation example
	Figure 17 is representing an applicative payload going through SCHC,		Figure 16 is representing an applicative payload going through SCHC,
	with fragmentation.		with fragmentation.
	An applicative payload of 478 bytes is passed to SCHC compression layer using		An applicative payload of 478 bytes is passed to SCHC compression layer
	rule 1, allowing to compress it to 440 bytes: 21 bits residue + 138 bytes		using rule 1, allowing to compress it to 282 bytes and 5 bits: 1 byte
	payload.		ruleID, 21 bits residue + 279 bytes payload.
	| RuleID | Compression residue | Payload |		| RuleID | Compression residue | Payload |
	+ ------ + ------------------- + --------- +		+ ------ + ------------------- + --------- +
	| 1 | 21 bits | 138 bytes |		| 1 | 21 bits | 279 bytes |
	Given the size of the payload, FPortUpDefault will be used.
	The current LoRaWAN MTU is 11 bytes, although 2 bytes FOpts are used by		The current LoRaWAN MTU is 11 bytes, although 2 bytes FOpts are used by
	LoRaWAN protocol: 9 bytes are available for SCHC payload.		LoRaWAN protocol: 9 bytes are available for SCHC payload + 1 byte FPort
	SCHC header is 2 bytes so 2 tiles are send in first fragment.		field. SCHC header is 2 bytes (including FPort) so 1 tile is sent in
			first fragment.
	| LoRaWAN Header | FOpts | RuleID | DTag | W | FCN | 2 tiles |		| LoRaWAN Header | LoRaWAN payload (6 bytes) |
	+ -------------- + ------- + ------ + ----- + ------ + ------ + ------- +		+ ------------------------------------- + ------------------------- +
	| XXXX | 2 bytes | 0 | 0 | 0 | 126 | 6 bytes |		| | FOpts | RuleID=20 | W | FCN | 1 tile |
			+ -------------- + ------- + ---------- + ----- + ------ + -------- +
			| XXXX | 2 bytes | 1 byte | 0 0 | 62 | 5 bytes |
	Content of the two tiles is:		Content of the tile is:
	| RuleID | Compression residue | Payload |		| RuleID | Compression residue | Payload |
	+ ------ + ------------------- + ------------------ +		+ ------ + ------------------- + ----------------- +
	| 1 | 21 bits | 2 bytes + 5 bits |		| 1 | 21 bits | 1 byte + 3 bits |
	Next transmission MTU is 242 bytes, no FOpts. 80 tiles are transmitted:		Next transmission MTU is 242 bytes, no FOpts. 48 tiles are transmitted:
	| LoRaWAN Header | RuleID | DTag | W | FCN | 80 tiles |		| LoRaWAN Header | LoRaWAN payload (241 bytes) |
	+ -------------- + ------ + ----- + ------ + ------ + --------- +		+ -------------- + -----------+ --------------------------- +
	| XXXX | 0 | 0 | 0 | 124 | 240 bytes |		| | RuleID=20 | W | FCN | 48 tiles |
			+ -------------- + ---------- + ----- + ------ + ---------- +
			| XXXX | 1 byte | 0 0 | 61 | 240 bytes |
	Next transmission MTU is 242 bytes, no FOpts. All 65 remaining tiles are		Next transmission MTU is 242 bytes, no FOpts. All 8 remaining tiles are
	transmitted, last tile is only 2 bytes. Padding is added for the remaining 6 bits.		transmitted, the last tile is only 2 bytes + 5 bits. Padding is added for
			the remaining 3 bits.
	| LoRaWAN Header | RuleID | DTag | W | FCN | MIC | 65 tiles | Padding=b'000 |		| LoRaWAN Header | LoRaWAN payload (39 bytes) |
	+ -------------- + ------ + ----- + ------ + ------ + ----- + --------- + ---------------- +		+ ---- + -----------+ ----------------------------------------------- +
	| XXXX | 0 | 0 | 0 | 127 | CRC32 | 194 bytes | 3 bits |		| | RuleID=20 | W | FCN | 8 tiles | Padding=b'000 |
			+ ---- + ---------- + -- + ------ + ----------------- + ------------- +
			| XXXX | 1 byte | 00 | 13 | 37 bytes + 5 bits | 3 bits |
	All packets have been received by the SCHC gateway, computed MIC is correct so		All packets have been received by the SCHC gateway, computed RCS is
	the following ACK is send to the device:		correct so the following ACK is sent to the device:
	| LoRaWAN Header | RuleID | DTag | W | C |		| LoRaWAN Header | LoRaWAN payload |
	+ -------------- + ------ + ----- + ------ + --- +		+ -------------- + --------- + ------------------- +
	| XXXX | 0 | 0 | 0 | 1 |		| | RuleID=20 | W | C | Padding |
			+ -------------- + --------- + ----- + - + ------- +
			| XXXX | 1 byte | 0 0 | 1 | 5 bits |
	Figure 17: Uplink example: compression and fragmentation		Figure 16: Uplink example: compression and fragmentation
	A.3. Downlink		A.3. Downlink
	An applicative payload of 43 bytes is passed to SCHC compression layer using		An applicative payload of 443 bytes is passed to SCHC compression layer
	rule 1, allowing to compress it to 24 bytes and 5 bits: 21 bits residue + 22 bytes		using rule 1, allowing to compress it to 130 bytes and 5 bits: 1 byte
	payload.		ruleId, 21 bits residue + 127 bytes payload.
	| RuleID | Compression residue | Payload |
	+ ------ + ------------------- + --------- +
	| 1 | 21 bits | 18 bytes |
	The current LoRaWAN MTU is 11 bytes, although 2 bytes FOpts are used by
	LoRaWAN protocol: 9 bytes are available for SCHC payload => it has to be fragmented.
	| LoRaWAN Header | FOpts | RuleID | W | FCN | 1 tile |
	+ -------------- + ------- + ------ + ------ + ------ + ------- +
	| XXXX | 2 bytes | 0 | 0 | 0 | 8 bytes |
	Content of the two tiles is:
	| RuleID | Compression residue | Payload |
	+ ------ + ------------------- + ------------------ +
	| 1 | 21 bits | 2 bytes + 5 bits |
	The receiver answers with an SCHC ACK
	| RuleID | W = 0 | C = b'1 |		| RuleID | Compression residue | Payload |
	+ ------ + ----- + ------- +		+ ------ + ------------------- + --------- +
	| 6 bits | 1 bit | 1 bit |		| 1 | 21 bits | 127 bytes |
	The second downlink is send, no FOpts:		The current LoRaWAN MTU is 51 bytes, no FOpts are used by LoRaWAN
			protocol: 48 bytes are available for SCHC payload + FPort field => it
			has to be fragmented.
	| LoRaWAN Header | RuleID | W | FCN | 1 tile |		| LoRaWAN Header | LoRaWAN payload (51 bytes) |
	+ -------------- + ------ + ------ + ------ + -------- +		+ ---- + ---------- + --------------------------------------------- +
	| XXXX | 0 | 1 | 0 | 10 bytes |		| | RuleID=21 | W | FCN | 1 tile | Padding=b'000000 |
			+ ---- + ---------- + --- + --- + -------------- + ---------------- +
			| XXXX | 1 byte | 0 | 0 | 50 bytes | 6 bits |
	The receiver answers with an SCHC ACK		Content of the tile is:
			| RuleID | Compression residue | Payload |
			+ ------ + ------------------- + ------------------ +
			| 1 | 21 bits | 46 bytes + 3 bits |
	| RuleID | W = 1 | C = b'1 |		The receiver answers with an SCHC ACK
	+ ------ + ----- + ------- +
	| 6 bits | 1 bit | 1 bit |
	The third downlink is send, no FOpts:		| FPortDown | LoRaWAN payload |
			+ --------- + ---------------------------------- +
			| RuleID | W = 0 | C = b'1 | Padding=b'000000 |
			+ --------- + ----- + ------- + ---------------- +
			| 1 byte | 1 bit | 1 bit | 6 bits |
	| LoRaWAN Header | RuleID | W | FCN | 1 tile |		The second downlink is sent, two FOpts:
	+ -------------- + ------ + ------ + ------ + -------- +
	| XXXX | 0 | 0 | 0 | 10 bytes |
	The receiver answers with an SCHC ACK		| LoRaWAN Header | LoRaWAN payload (49 bytes) |
			+ --------------------------- + ------------------ + ---------------- +
			| | FOpts | RuleID=21 | W | FCN | 1 tile | Padding=b'000000 |
			+ ---- + ------- + ---------- + - + --- + -------- + ---------------- +
			| XXXX | 2 bytes | 1 byte | 1 | 0 | 48 bytes | 6 bits |
	| RuleID | W = 0 | C = 1 |		The receiver answers with an SCHC ACK
	+ ------ + ----- + ------- +
	| 6 bits | 1 bit | 1 bit |
	The last downlink is send, no FOpts:		| FPortDown | LoRaWAN payload |
			+ --------- + ---------------------------------- +
			| RuleID | W = 1 | C = b'1 | Padding=b'000000 |
			+ --------- + ----- + ------- + ---------------- +
			| 1 byte | 1 bit | 1 bit | 6 bits |
			The last downlink is sent, no FOpts:
	| LoRaWAN Header | RuleID | W | FCN | 1 tile |		| LoRaWAN Header | LoRaWAN payload (33 bytes) |
	+ -------------- + ------ + ------ + ------ + -------- +		+ ---- + ---------- + ----------------------------------------------- +
	| XXXX | 0 | 1 | 1 | 2 bytes |		| | RuleID=21 | W | FCN | 1 tile | Padding=b'0 |
			+ ---- + ---------- + --- + --- + --------------------- + ----------- +
			| XXXX | 1 byte | 0 | 1 | 32 bytes + 5 bits | 1 bit |
	The receiver answers with an SCHC ACK		The receiver answers with an SCHC ACK
	| RuleID | W = 1 | C = 1 |		| FPortDown | LoRaWAN payload |
	+ ------ + ----- + ------- +		+ --------- + ---------------------------------- +
	| 6 bits | 1 bit | 1 bit |		| RuleID | W = 0 | C = b'1 | Padding=b'000000 |
			+ --------- + ----- + ------- + ---------------- +
			| 1 byte | 1 bit | 1 bit | 6 bits |
	Figure 18: Downlink example: compression and fragmentation		Figure 17: Downlink example: compression and fragmentation
	Appendix B. Note		Appendix B. Note
	Authors' Addresses		Authors' Addresses
	Olivier Gimenez (editor)		Olivier Gimenez (editor)
	Semtech		Semtech
	14 Chemin des Clos		14 Chemin des Clos
	Meylan		Meylan
	France		France
	Email: ogimenez@semtech.com		Email: ogimenez@semtech.com
	Ivaylo Petrov (editor)		Ivaylo Petrov (editor)
	Acklio		Acklio
	2bis rue de la Chataigneraie		1137A Avenue des Champs Blancs
	35510 Cesson-Sevigne Cedex		35510 Cesson-Sevigne Cedex
	France		France
	Email: ivaylo@ackl.io		Email: ivaylo@ackl.io
			Julien Catalano
			Kerlink
			1 rue Jacqueline Auriol
			35235 Thorigne-Fouillard
			France
			Email: j.catalano@kerlink.fr
End of changes. 156 change blocks.
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