< draft-ietf-lpwan-ipv6-static-context-hc-20.txt		draft-ietf-lpwan-ipv6-static-context-hc-21.txt >
	lpwan Working Group A. Minaburo		lpwan Working Group A. Minaburo
	Internet-Draft Acklio		Internet-Draft Acklio
	Intended status: Standards Track L. Toutain		Intended status: Standards Track L. Toutain
	Expires: January 23, 2020 IMT-Atlantique		Expires: January 24, 2020 IMT-Atlantique
	C. Gomez		C. Gomez
	Universitat Politecnica de Catalunya		Universitat Politecnica de Catalunya
	D. Barthel		D. Barthel
	Orange Labs		Orange Labs
	JC. Zuniga		JC. Zuniga
	SIGFOX		SIGFOX
	July 22, 2019		July 23, 2019
	Static Context Header Compression (SCHC) and fragmentation for LPWAN,		Static Context Header Compression (SCHC) and fragmentation for LPWAN,
	application to UDP/IPv6		application to UDP/IPv6
	draft-ietf-lpwan-ipv6-static-context-hc-20		draft-ietf-lpwan-ipv6-static-context-hc-21
	Abstract		Abstract
	This document defines the Static Context Header Compression (SCHC)		This document defines the Static Context Header Compression (SCHC)
	framework, which provides both header compression and fragmentation		framework, which provides both header compression and fragmentation
	functionalities. SCHC has been designed for Low Power Wide Area		functionalities. SCHC has been designed for Low Power Wide Area
	Networks (LPWAN).		Networks (LPWAN).
	SCHC compression is based on a common static context stored in both		SCHC compression is based on a common static context stored in both
	the LPWAN device and the network side. This document defines a		the LPWAN device and the network side. This document defines a
	skipping to change at page 2, line 20 ¶		skipping to change at page 2, line 20 ¶
	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 23, 2020.		This Internet-Draft will expire on January 24, 2020.
	Copyright Notice		Copyright Notice
	Copyright (c) 2019 IETF Trust and the persons identified as the		Copyright (c) 2019 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 3, line 35 ¶		skipping to change at page 3, line 35 ¶
	8.4. SCHC F/R modes . . . . . . . . . . . . . . . . . . . . . 33		8.4. SCHC F/R modes . . . . . . . . . . . . . . . . . . . . . 33
	8.4.1. No-ACK mode . . . . . . . . . . . . . . . . . . . . . 33		8.4.1. No-ACK mode . . . . . . . . . . . . . . . . . . . . . 33
	8.4.2. ACK-Always mode . . . . . . . . . . . . . . . . . . . 35		8.4.2. ACK-Always mode . . . . . . . . . . . . . . . . . . . 35
	8.4.3. ACK-on-Error mode . . . . . . . . . . . . . . . . . . 41		8.4.3. ACK-on-Error mode . . . . . . . . . . . . . . . . . . 41
	9. Padding management . . . . . . . . . . . . . . . . . . . . . 48		9. Padding management . . . . . . . . . . . . . . . . . . . . . 48
	10. SCHC Compression for IPv6 and UDP headers . . . . . . . . . . 49		10. SCHC Compression for IPv6 and UDP headers . . . . . . . . . . 49
	10.1. IPv6 version field . . . . . . . . . . . . . . . . . . . 49		10.1. IPv6 version field . . . . . . . . . . . . . . . . . . . 49
	10.2. IPv6 Traffic class field . . . . . . . . . . . . . . . . 50		10.2. IPv6 Traffic class field . . . . . . . . . . . . . . . . 50
	10.3. Flow label field . . . . . . . . . . . . . . . . . . . . 50		10.3. Flow label field . . . . . . . . . . . . . . . . . . . . 50
	10.4. Payload Length field . . . . . . . . . . . . . . . . . . 50		10.4. Payload Length field . . . . . . . . . . . . . . . . . . 50
	10.5. Next Header field . . . . . . . . . . . . . . . . . . . 50		10.5. Next Header field . . . . . . . . . . . . . . . . . . . 51
	10.6. Hop Limit field . . . . . . . . . . . . . . . . . . . . 51		10.6. Hop Limit field . . . . . . . . . . . . . . . . . . . . 51
	10.7. IPv6 addresses fields . . . . . . . . . . . . . . . . . 51		10.7. IPv6 addresses fields . . . . . . . . . . . . . . . . . 51
	10.7.1. IPv6 source and destination prefixes . . . . . . . . 51		10.7.1. IPv6 source and destination prefixes . . . . . . . . 51
	10.7.2. IPv6 source and destination IID . . . . . . . . . . 52		10.7.2. IPv6 source and destination IID . . . . . . . . . . 52
	10.8. IPv6 extensions . . . . . . . . . . . . . . . . . . . . 52		10.8. IPv6 extensions . . . . . . . . . . . . . . . . . . . . 52
	10.9. UDP source and destination port . . . . . . . . . . . . 52		10.9. UDP source and destination port . . . . . . . . . . . . 52
	10.10. UDP length field . . . . . . . . . . . . . . . . . . . . 53		10.10. UDP length field . . . . . . . . . . . . . . . . . . . . 53
	10.11. UDP Checksum field . . . . . . . . . . . . . . . . . . . 53		10.11. UDP Checksum field . . . . . . . . . . . . . . . . . . . 53
	11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 54		11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 54
	12. Security considerations . . . . . . . . . . . . . . . . . . . 54		12. Security considerations . . . . . . . . . . . . . . . . . . . 54
	12.1. Security considerations for SCHC		12.1. Security considerations for SCHC
	Compression/Decompression . . . . . . . . . . . . . . . 54		Compression/Decompression . . . . . . . . . . . . . . . 54
	12.2. Security considerations for SCHC		12.2. Security considerations for SCHC
	Fragmentation/Reassembly . . . . . . . . . . . . . . . . 55		Fragmentation/Reassembly . . . . . . . . . . . . . . . . 55
	13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 56		13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 56
	14. References . . . . . . . . . . . . . . . . . . . . . . . . . 56		14. References . . . . . . . . . . . . . . . . . . . . . . . . . 56
	14.1. Normative References . . . . . . . . . . . . . . . . . . 56		14.1. Normative References . . . . . . . . . . . . . . . . . . 56
	14.2. Informative References . . . . . . . . . . . . . . . . . 56		14.2. Informative References . . . . . . . . . . . . . . . . . 56
	Appendix A. Compression Examples . . . . . . . . . . . . . . . . 57		Appendix A. Compression Examples . . . . . . . . . . . . . . . . 57
	Appendix B. Fragmentation Examples . . . . . . . . . . . . . . . 60		Appendix B. Fragmentation Examples . . . . . . . . . . . . . . . 60
	Appendix C. Fragmentation State Machines . . . . . . . . . . . . 67		Appendix C. Fragmentation State Machines . . . . . . . . . . . . 68
	Appendix D. SCHC Parameters . . . . . . . . . . . . . . . . . . 73		Appendix D. SCHC Parameters . . . . . . . . . . . . . . . . . . 74
	Appendix E. Supporting multiple window sizes for fragmentation . 75		Appendix E. Supporting multiple window sizes for fragmentation . 76
	Appendix F. Downlink SCHC Fragment transmission . . . . . . . . 75		Appendix F. Downlink SCHC Fragment transmission . . . . . . . . 76
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 76		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 77
	1. Introduction		1. Introduction
	This document defines the Static Context Header Compression (SCHC)		This document defines the Static Context Header Compression (SCHC)
	framework, which provides both header compression and fragmentation		framework, which provides both header compression and fragmentation
	functionalities. SCHC has been designed for Low Power Wide Area		functionalities. SCHC has been designed for Low Power Wide Area
	Networks (LPWAN).		Networks (LPWAN).
	LPWAN technologies impose some strict limitations on traffic. For		LPWAN technologies impose some strict limitations on traffic. For
	instance, devices sleep most of the time and may only receive data		instance, devices sleep most of the time and may only receive data
	skipping to change at page 50, line 40 ¶		skipping to change at page 50, line 40 ¶
	o One possibility is to not compress the field and send the original		o One possibility is to not compress the field and send the original
	value. In the Rule, TV is not set to any particular value, MO is		value. In the Rule, TV is not set to any particular value, MO is
	set to "ignore" and CDA is set to "value-sent".		set to "ignore" and CDA is set to "value-sent".
	o If some upper bits in the field are constant and known, a better		o If some upper bits in the field are constant and known, a better
	option is to only send the LSBs. In the Rule, TV is set to a		option is to only send the LSBs. In the Rule, TV is set to a
	value with the stable known upper part, MO is set to MSB(x) and		value with the stable known upper part, MO is set to MSB(x) and
	CDA to LSB.		CDA to LSB.
			ECN functionality depends on both bits of the ECN field, which are
			the 2 LSBs of this field, hence sending only a single LSB of this
			field is NOT RECOMMENDED.
	10.4. Payload Length field		10.4. Payload Length field
	This field can be elided for the transmission on the LPWAN network.		This field can be elided for the transmission on the LPWAN network.
	The SCHC C/D recomputes the original payload length value. In the		The SCHC C/D recomputes the original payload length value. In the
	Field Descriptor, TV is not set, MO is set to "ignore" and CDA is		Field Descriptor, TV is not set, MO is set to "ignore" and CDA is
	"compute-*".		"compute-*".
	10.5. Next Header field		10.5. Next Header field
	If the Next Header field does not vary and is known by both sides,		If the Next Header field does not vary and is known by both sides,
	skipping to change at page 56, line 7 ¶		skipping to change at page 56, line 10 ¶
	spoofed ACK, with all bitmap bits set to 0, will trigger the		spoofed ACK, with all bitmap bits set to 0, will trigger the
	repetition of WINDOW_SIZE tiles. This protocol loop amplification		repetition of WINDOW_SIZE tiles. This protocol loop amplification
	depletes the energy source of the target node and consumes the		depletes the energy source of the target node and consumes the
	channel bandwidth. Similarly, a spoofed ACK REQ will trigger the		channel bandwidth. Similarly, a spoofed ACK REQ will trigger the
	sending of a SCHC ACK, which may be much larger than the ACK REQ if		sending of a SCHC ACK, which may be much larger than the ACK REQ if
	WINDOW_SIZE is large. These consequences should be borne in mind		WINDOW_SIZE is large. These consequences should be borne in mind
	when defining profiles for SCHC over specific LPWAN technologies.		when defining profiles for SCHC over specific LPWAN technologies.
	13. Acknowledgements		13. Acknowledgements
	Thanks to Sergio Aguilar Romero, Carsten Bormann, Philippe Clavier,		Thanks to Sergio Aguilar Romero, Carsten Bormann, David Black,
	Daniel Ducuara Beltran Diego Dujovne, Eduardo Ingles Sanchez,		Philippe Clavier, Daniel Ducuara Beltran Diego Dujovne, Eduardo
	Arunprabhu Kandasamy, Suresh Krishnan, Rahul Jadhav, Sergio Lopez		Ingles Sanchez, Arunprabhu Kandasamy, Suresh Krishnan, Rahul Jadhav,
	Bernal, Antony Markovski, Alexander Pelov, Charles Perkins, Edgar		Sergio Lopez Bernal, Antony Markovski, Alexander Pelov, Charles
	Ramos, Shoichi Sakane, and Pascal Thubert for useful design		Perkins, Edgar Ramos, Shoichi Sakane, and Pascal Thubert for useful
	consideration and comments.		design consideration and comments.
	Carles Gomez has been funded in part by the Spanish Government		Carles Gomez has been funded in part by the Spanish Government
	(Ministerio de Educacion, Cultura y Deporte) through the Jose		(Ministerio de Educacion, Cultura y Deporte) through the Jose
	Castillejo grant CAS15/00336, and by the ERDF and the Spanish		Castillejo grant CAS15/00336, and by the ERDF and the Spanish
	Government through project TEC2016-79988-P. Part of his contribution		Government through project TEC2016-79988-P. Part of his contribution
	to this work has been carried out during his stay as a visiting		to this work has been carried out during his stay as a visiting
	scholar at the Computer Laboratory of the University of Cambridge.		scholar at the Computer Laboratory of the University of Cambridge.
	14. References		14. References
	skipping to change at page 58, line 35 ¶		skipping to change at page 58, line 40 ¶
	In some LPWAN technologies, only the Devs have a device ID. When		In some LPWAN technologies, only the Devs have a device ID. When
	such technologies are used, it is necessary to statically define an		such technologies are used, it is necessary to statically define an
	IID for the Link Local address for the SCHC C/D.		IID for the Link Local address for the SCHC C/D.
	Rule 0		Rule 0
	+----------------+--+--+--+---------+--------+------------++------+		+----------------+--+--+--+---------+--------+------------++------+
	| Field |FL|FP|DI| Value | Match | Comp Decomp|| Sent |		| Field |FL|FP|DI| Value | Match | Comp Decomp|| Sent |
	| | | | | | Opera. | Action ||[bits]|		| | | | | | Opera. | Action ||[bits]|
	+----------------+--+--+--+---------+---------------------++------+		+----------------+--+--+--+---------+---------------------++------+
	|IPv6 version |4 |1 |Bi|6 | equal | not-sent || |		|IPv6 Version |4 |1 |Bi|6 | ignore | not-sent || |
	|IPv6 DiffServ |8 |1 |Bi|0 | equal | not-sent || |		|IPv6 DiffServ |8 |1 |Bi|0 | equal | not-sent || |
	|IPv6 Flow Label |20|1 |Bi|0 | equal | not-sent || |		|IPv6 Flow Label |20|1 |Bi|0 | equal | not-sent || |
	|IPv6 Length |16|1 |Bi| | ignore | comp-length|| |		|IPv6 Length |16|1 |Bi| | ignore | compute-* || |
	|IPv6 Next Header|8 |1 |Bi|17 | equal | not-sent || |		|IPv6 Next Header|8 |1 |Bi|17 | equal | not-sent || |
	|IPv6 Hop Limit |8 |1 |Bi|255 | ignore | not-sent || |		|IPv6 Hop Limit |8 |1 |Bi|255 | ignore | not-sent || |
	|IPv6 DevPrefix |64|1 |Bi|FE80::/64| equal | not-sent || |		|IPv6 DevPrefix |64|1 |Bi|FE80::/64| equal | not-sent || |
	|IPv6 DevIID |64|1 |Bi| | ignore | DevIID || |		|IPv6 DevIID |64|1 |Bi| | ignore | DevIID || |
	|IPv6 AppPrefix |64|1 |Bi|FE80::/64| equal | not-sent || |		|IPv6 AppPrefix |64|1 |Bi|FE80::/64| equal | not-sent || |
	|IPv6 AppIID |64|1 |Bi|::1 | equal | not-sent || |		|IPv6 AppIID |64|1 |Bi|::1 | equal | not-sent || |
	+================+==+==+==+=========+========+============++======+		+================+==+==+==+=========+========+============++======+
	|UDP DevPort |16|1 |Bi|123 | equal | not-sent || |		|UDP DevPort |16|1 |Bi|123 | equal | not-sent || |
	|UDP AppPort |16|1 |Bi|124 | equal | not-sent || |		|UDP AppPort |16|1 |Bi|124 | equal | not-sent || |
	|UDP Length |16|1 |Bi| | ignore | comp-length|| |		|UDP Length |16|1 |Bi| | ignore | compute-* || |
	|UDP checksum |16|1 |Bi| | ignore | comp-chk || |		|UDP checksum |16|1 |Bi| | ignore | compute-* || |
	+================+==+==+==+=========+========+============++======+		+================+==+==+==+=========+========+============++======+
	Rule 1		Rule 1
	+----------------+--+--+--+---------+--------+------------++------+		+----------------+--+--+--+---------+--------+------------++------+
	| Field |FL|FP|DI| Value | Match | Action || Sent |		| Field |FL|FP|DI| Value | Match | Action || Sent |
	| | | | | | Opera. | Action ||[bits]|		| | | | | | Opera. | Action ||[bits]|
	+----------------+--+--+--+---------+--------+------------++------+		+----------------+--+--+--+---------+--------+------------++------+
	|IPv6 version |4 |1 |Bi|6 | equal | not-sent || |		|IPv6 Version |4 |1 |Bi|6 | ignore | not-sent || |
	|IPv6 DiffServ |8 |1 |Bi|0 | equal | not-sent || |		|IPv6 DiffServ |8 |1 |Bi|0 | equal | not-sent || |
	|IPv6 Flow Label |20|1 |Bi|0 | equal | not-sent || |		|IPv6 Flow Label |20|1 |Bi|0 | equal | not-sent || |
	|IPv6 Length |16|1 |Bi| | ignore | comp-length|| |		|IPv6 Length |16|1 |Bi| | ignore | compute-* || |
	|IPv6 Next Header|8 |1 |Bi|17 | equal | not-sent || |		|IPv6 Next Header|8 |1 |Bi|17 | equal | not-sent || |
	|IPv6 Hop Limit |8 |1 |Bi|255 | ignore | not-sent || |		|IPv6 Hop Limit |8 |1 |Bi|255 | ignore | not-sent || |
	|IPv6 DevPrefix |64|1 |Bi|[alpha/64, match- |mapping-sent|| 1 |		|IPv6 DevPrefix |64|1 |Bi|[alpha/64, match- |mapping-sent|| 1 |
	| | | | |fe80::/64] mapping| || |		| | | | |fe80::/64] mapping| || |
	|IPv6 DevIID |64|1 |Bi| | ignore | DevIID || |		|IPv6 DevIID |64|1 |Bi| | ignore | DevIID || |
	|IPv6 AppPrefix |64|1 |Bi|[beta/64,| match- |mapping-sent|| 2 |		|IPv6 AppPrefix |64|1 |Bi|[beta/64,| match- |mapping-sent|| 2 |
	| | | | |alpha/64,| mapping| || |		| | | | |alpha/64,| mapping| || |
	| | | | |fe80::64]| | || |		| | | | |fe80::64]| | || |
	|IPv6 AppIID |64|1 |Bi|::1000 | equal | not-sent || |		|IPv6 AppIID |64|1 |Bi|::1000 | equal | not-sent || |
	+================+==+==+==+=========+========+============++======+		+================+==+==+==+=========+========+============++======+
	|UDP DevPort |16|1 |Bi|5683 | equal | not-sent || |		|UDP DevPort |16|1 |Bi|5683 | equal | not-sent || |
	|UDP AppPort |16|1 |Bi|5683 | equal | not-sent || |		|UDP AppPort |16|1 |Bi|5683 | equal | not-sent || |
	|UDP Length |16|1 |Bi| | ignore | comp-length|| |		|UDP Length |16|1 |Bi| | ignore | compute-* || |
	|UDP checksum |16|1 |Bi| | ignore | comp-chk || |		|UDP checksum |16|1 |Bi| | ignore | compute-* || |
	+================+==+==+==+=========+========+============++======+		+================+==+==+==+=========+========+============++======+
	Rule 2		Rule 2
	+----------------+--+--+--+---------+--------+------------++------+		+----------------+--+--+--+---------+--------+------------++------+
	| Field |FL|FP|DI| Value | Match | Action || Sent |		| Field |FL|FP|DI| Value | Match | Action || Sent |
	| | | | | | Opera. | Action ||[bits]|		| | | | | | Opera. | Action ||[bits]|
	+----------------+--+--+--+---------+--------+------------++------+		+----------------+--+--+--+---------+--------+------------++------+
	|IPv6 version |4 |1 |Bi|6 | equal | not-sent || |		|IPv6 Version |4 |1 |Bi|6 | ignore | not-sent || |
	|IPv6 DiffServ |8 |1 |Bi|0 | equal | not-sent || |		|IPv6 DiffServ |8 |1 |Bi|0 | equal | not-sent || |
	|IPv6 Flow Label |20|1 |Bi|0 | equal | not-sent || |		|IPv6 Flow Label |20|1 |Bi|0 | equal | not-sent || |
	|IPv6 Length |16|1 |Bi| | ignore | comp-length|| |		|IPv6 Length |16|1 |Bi| | ignore | compute-* || |
	|IPv6 Next Header|8 |1 |Bi|17 | equal | not-sent || |		|IPv6 Next Header|8 |1 |Bi|17 | equal | not-sent || |
	|IPv6 Hop Limit |8 |1 |Up|255 | ignore | not-sent || |		|IPv6 Hop Limit |8 |1 |Up|255 | ignore | not-sent || |
	|IPv6 Hop Limit |8 |1 |Dw| | ignore | value-sent || 8 |		|IPv6 Hop Limit |8 |1 |Dw| | ignore | value-sent || 8 |
	|IPv6 DevPrefix |64|1 |Bi|alpha/64 | equal | not-sent || |		|IPv6 DevPrefix |64|1 |Bi|alpha/64 | equal | not-sent || |
	|IPv6 DevIID |64|1 |Bi| | ignore | DevIID || |		|IPv6 DevIID |64|1 |Bi| | ignore | DevIID || |
	|IPv6 AppPrefix |64|1 |Bi|gamma/64 | equal | not-sent || |		|IPv6 AppPrefix |64|1 |Bi|gamma/64 | equal | not-sent || |
	|IPv6 AppIID |64|1 |Bi|::1000 | equal | not-sent || |		|IPv6 AppIID |64|1 |Bi|::1000 | equal | not-sent || |
	+================+==+==+==+=========+========+============++======+		+================+==+==+==+=========+========+============++======+
	|UDP DevPort |16|1 |Bi|8720 | MSB(12)| LSB || 4 |		|UDP DevPort |16|1 |Bi|8720 | MSB(12)| LSB || 4 |
	|UDP AppPort |16|1 |Bi|8720 | MSB(12)| LSB || 4 |		|UDP AppPort |16|1 |Bi|8720 | MSB(12)| LSB || 4 |
	|UDP Length |16|1 |Bi| | ignore | comp-length|| |		|UDP Length |16|1 |Bi| | ignore | compute-* || |
	|UDP checksum |16|1 |Bi| | ignore | comp-chk || |		|UDP checksum |16|1 |Bi| | ignore | compute-* || |
	+================+==+==+==+=========+========+============++======+		+================+==+==+==+=========+========+============++======+
	Figure 26: Context Rules		Figure 26: Context Rules
	All the fields described in the three Rules depicted on Figure 26 are		All the fields described in the three Rules depicted on Figure 26 are
	present in the IPv6 and UDP headers. The DevIID-DID value is found		present in the IPv6 and UDP headers. The DevIID-DID value is found
	in the L2 header.		in the L2 header.
	The second and third Rules use global addresses. The way the Dev		The second and third Rules use global addresses. The way the Dev
	learns the prefix is not in the scope of the document.		learns the prefix is not in the scope of the document.
	The third Rule compresses each port number to 4 bits.		The third Rule compresses each port number to 4 bits.
End of changes. 19 change blocks.
	28 lines changed or deleted		34 lines changed or added
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