< draft-ietf-6lo-btle-01.txt		draft-ietf-6lo-btle-02.txt >
	6Lo Working Group J. Nieminen		6Lo Working Group J. Nieminen
	Internet-Draft T. Savolainen		Internet-Draft T. Savolainen
	Intended status: Standards Track M. Isomaki		Intended status: Standards Track M. Isomaki
	Expires: November 3, 2014 Nokia		Expires: December 13, 2014 Nokia
	B. Patil		B. Patil
	AT&T		AT&T
	Z. Shelby		Z. Shelby
	Arm		Arm
	C. Gomez		C. Gomez
	Universitat Politecnica de Catalunya/i2CAT		Universitat Politecnica de Catalunya/i2CAT
	May 2, 2014		June 11, 2014
	Transmission of IPv6 Packets over BLUETOOTH(R) Low Energy		Transmission of IPv6 Packets over BLUETOOTH(R) Low Energy
	draft-ietf-6lo-btle-01		draft-ietf-6lo-btle-02
	Abstract		Abstract
	Bluetooth Smart is the brand name for the low energy feature in the		Bluetooth Smart is the brand name for the Bluetooth low energy
	Bluetooth specification defined by the Bluetooth Special Interest		feature in the Bluetooth specification defined by the Bluetooth
	Group. The standard Bluetooth radio has been widely implemented and		Special Interest Group. The standard Bluetooth radio has been widely
	available in mobile phones, notebook computers, audio headsets and		implemented and available in mobile phones, notebook computers, audio
	many other devices. The low power version of Bluetooth is a		headsets and many other devices. The low power version of Bluetooth
	specification that enables the use of this air interface with devices		is a specification that enables the use of this air interface with
	such as sensors, smart meters, appliances, etc. The low power		devices such as sensors, smart meters, appliances, etc. The low
	variant of Bluetooth is standardized since the revision 4.0 of the		power variant of Bluetooth is standardized since the revision 4.0 of
	Bluetooth specifications, although version 4.1 or newer is required		the Bluetooth specifications, although version 4.1 or newer is
	for IPv6. This document describes how IPv6 is transported over		required for IPv6. This document describes how IPv6 is transported
	Bluetooth Low Energy using 6LoWPAN techniques.		over Bluetooth low energy using 6LoWPAN techniques.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://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 November 3, 2014.		This Internet-Draft will expire on December 13, 2014.
	Copyright Notice		Copyright Notice
	Copyright (c) 2014 IETF Trust and the persons identified as the		Copyright (c) 2014 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
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 2, line 25 ¶		skipping to change at page 2, line 25 ¶
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	1.1. Terminology and Requirements Language . . . . . . . . . . 3		1.1. Terminology and Requirements Language . . . . . . . . . . 3
	2. Bluetooth Low Energy . . . . . . . . . . . . . . . . . . . . 3		2. Bluetooth Low Energy . . . . . . . . . . . . . . . . . . . . 3
	2.1. Bluetooth Low Energy stack . . . . . . . . . . . . . . . 4		2.1. Bluetooth LE stack . . . . . . . . . . . . . . . . . . . 4
	2.2. Link layer roles and topology . . . . . . . . . . . . . . 4		2.2. Link layer roles and topology . . . . . . . . . . . . . . 5
	2.3. Bluetooth LE device addressing . . . . . . . . . . . . . 5		2.3. Bluetooth LE device addressing . . . . . . . . . . . . . 5
	2.4. Bluetooth LE packets sizes and MTU . . . . . . . . . . . 5		2.4. Bluetooth LE packets sizes and MTU . . . . . . . . . . . 6
	3. Specification of IPv6 over Bluetooth Low Energy . . . . . . . 6		3. Specification of IPv6 over Bluetooth Low Energy . . . . . . . 6
	3.1. Protocol stack . . . . . . . . . . . . . . . . . . . . . 6		3.1. Protocol stack . . . . . . . . . . . . . . . . . . . . . 6
	3.2. Link model . . . . . . . . . . . . . . . . . . . . . . . 7		3.2. Link model . . . . . . . . . . . . . . . . . . . . . . . 7
	3.2.1. Stateless address autoconfiguration . . . . . . . . . 8		3.2.1. Stateless address autoconfiguration . . . . . . . . . 8
	3.2.2. Neighbor discovery . . . . . . . . . . . . . . . . . 8		3.2.2. Neighbor discovery . . . . . . . . . . . . . . . . . 8
	3.2.3. Header compression . . . . . . . . . . . . . . . . . 9		3.2.3. Header compression . . . . . . . . . . . . . . . . . 9
	3.2.3.1. Remote destination example . . . . . . . . . . . 10		3.2.3.1. Remote destination example . . . . . . . . . . . 10
	3.2.4. Unicast and Multicast address mapping . . . . . . . . 11		3.2.4. Unicast and Multicast address mapping . . . . . . . . 11
	3.3. Internet connectivity scenarios . . . . . . . . . . . . . 11		3.3. Internet connectivity scenarios . . . . . . . . . . . . . 11
	4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12		4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
	skipping to change at page 3, line 29 ¶		skipping to change at page 3, line 29 ¶
	Bluetooth LE links. This document specifies the details of IPv6		Bluetooth LE links. This document specifies the details of IPv6
	transmission over Bluetooth LE links.		transmission over Bluetooth LE links.
	1.1. Terminology and Requirements Language		1.1. Terminology and Requirements Language
	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", "MAY", and "OPTIONAL" in this
	document are to be interpreted as described in RFC 2119 [RFC2119].		document are to be interpreted as described in RFC 2119 [RFC2119].
	The terms 6LN, 6LR and 6LBR are defined as in [RFC6775], with an		The terms 6LN, 6LR and 6LBR are defined as in [RFC6775], with an
	addition that Bluetooth LE central and Bluetooth LE peripheral can		addition that Bluetooth LE central and Bluetooth LE peripheral (see
	both be either 6LN or 6LBR.		Section 2.2) can both be either 6LN or 6LBR.
	2. Bluetooth Low Energy		2. Bluetooth Low Energy
	Bluetooth LE is designed for transferring small amounts of data		Bluetooth LE is designed for transferring small amounts of data
	infrequently at modest data rates at a very low cost per bit.		infrequently at modest data rates at a very low cost per bit.
	Bluetooth Special Interest Group (Bluetooth SIG) has introduced two		Bluetooth Special Interest Group (Bluetooth SIG) has introduced two
	trademarks, Bluetooth Smart for single-mode devices (a device that		trademarks, Bluetooth Smart for single-mode devices (a device that
	only supports Bluetooth LE) and Bluetooth Smart Ready for dual-mode		only supports Bluetooth LE) and Bluetooth Smart Ready for dual-mode
	devices. In the rest of the document, the term Bluetooth LE refers		devices (devices that support both Bluetooth and Bluetooth LE). In
	to both types of devices.		the rest of the document, the term Bluetooth LE refers to both types
			of devices.
	Bluetooth LE was introduced in Bluetooth 4.0 and further enhanced in		Bluetooth LE was introduced in Bluetooth 4.0 and further enhanced in
	Bluetooth 4.1 [BTCorev4.1]. Bluetooth SIG will also publish Internet		Bluetooth 4.1 [BTCorev4.1]. Bluetooth SIG will also publish Internet
	Protocol Support Profile (IPSP) [IPSP], which includes Internet		Protocol Support Profile (IPSP) [IPSP], which includes Internet
	Protocol Support Service (IPSS) and that enables discovery of IP-		Protocol Support Service (IPSS) and that enables discovery of IP-
	enabled devices and establishment of link-layer connection for		enabled devices and establishment of link-layer connection for
	transporting IPv6 packets. IPv6 over Bluetooth LE is dependent on		transporting IPv6 packets. IPv6 over Bluetooth LE is dependent on
	both Bluetooth 4.1 and IPSP.		both Bluetooth 4.1 and IPSP.
	Devices such as mobile phones, notebooks, tablets and other handheld		Devices such as mobile phones, notebooks, tablets and other handheld
	computing devices which will include Bluetooth 4.1 chipsets will also		computing devices which will include Bluetooth 4.1 chipsets will also
	have the low-energy functionality of Bluetooth. Bluetooth LE will		have the low-energy functionality of Bluetooth. Bluetooth LE will
	also be included in many different types of accessories that		also be included in many different types of accessories that
	collaborate with mobile devices such as phones, tablets and notebook		collaborate with mobile devices such as phones, tablets and notebook
	computers. An example of a use case for a Bluetooth LE accessory is		computers. An example of a use case for a Bluetooth LE accessory is
	a heart rate monitor that sends data via the mobile phone to a server		a heart rate monitor that sends data via the mobile phone to a server
	on the Internet.		on the Internet.
	2.1. Bluetooth Low Energy stack		2.1. Bluetooth LE stack
	The lower layer of the Bluetooth LE stack consists of the Physical		The lower layer of the Bluetooth LE stack consists of the Physical
	(PHY) and the Link Layer (LL). The Physical Layer transmits and		(PHY) and the Link Layer (LL). The Physical Layer transmits and
	receives the actual packets. The Link Layer is responsible for		receives the actual packets. The Link Layer is responsible for
	providing medium access, connection establishment, error control and		providing medium access, connection establishment, error control and
	flow control. The upper layer consists of the Logical Link Control		flow control. The upper layer consists of the Logical Link Control
	and Adaptation Protocol (L2CAP), Attribute Protocol (ATT), Generic		and Adaptation Protocol (L2CAP), Attribute Protocol (ATT), Generic
	Attribute Profile (GATT) and Generic Access Profile (GAP) as shown in		Attribute Profile (GATT) and Generic Access Profile (GAP) as shown in
	Figure 1. The device internal Host Controller Interface (HCI)		Figure 1. The device internal Host Controller Interface (HCI)
	separates the lower layers, often implemented in the Bluetooth		separates the lower layers, often implemented in the Bluetooth
	skipping to change at page 4, line 47 ¶		skipping to change at page 5, line 7 ¶
	- - -+-----------------------+-------------------------+- - - HCI		- - -+-----------------------+-------------------------+- - - HCI
	| Link Layer | Direct Test Mode |		| Link Layer | Direct Test Mode |
	+-------------------------------------------------+		+-------------------------------------------------+
	| Physical Layer |		| Physical Layer |
	+-------------------------------------------------+		+-------------------------------------------------+
	Figure 1: Bluetooth LE Protocol Stack		Figure 1: Bluetooth LE Protocol Stack
	2.2. Link layer roles and topology		2.2. Link layer roles and topology
	Bluetooth LE defines two Link Layer roles: the Bluetooth LE central		Bluetooth LE defines two GAP roles of relevance herein: the Bluetooth
	role and the Bluetooth LE peripheral role. A device in the central		LE central role and the Bluetooth LE peripheral role. A device in
	role, which is called central from now on, has traditionally been		the central role, which is called central from now on, has
	able to manage multiple simultaneous connections with a number of		traditionally been able to manage multiple simultaneous connections
	devices in the peripheral role, called peripherals from now on. A		with a number of devices in the peripheral role, called peripherals
	peripheral is commonly connected to a single central, but since		from now on. A peripheral is commonly connected to a single central,
	Bluetooth 4.1 can also connect to multiple centrals. In this		but since Bluetooth 4.1 can also connect to multiple centrals. In
	document for IPv6 networking purposes the Bluetooth LE network (i.e.		this document for IPv6 networking purposes the Bluetooth LE network
	a Bluetooth LE piconet) follows a star topology shown in the		(i.e. a Bluetooth LE piconet) follows a star topology shown in the
	Figure 2, where the router typically implements the Bluetooth LE		Figure 2, where the router typically implements the Bluetooth LE
	central role and nodes Bluetooth LE peripheral roles. In the future		central role and nodes implement the Bluetooth LE peripheral role.
	mesh networking may be defined for IPv6 over Bluetooth LE.		In the future mesh networking may be defined for IPv6 over Bluetooth
			LE.
	Node --. .-- Node		Node --. .-- Node
	\ /		\ /
	Node ---- Router ---- Node		Node ---- Router ---- Node
	/ \		/ \
	Node --' '-- Node		Node --' '-- Node
	Figure 2: Bluetooth LE Star Topology		Figure 2: Bluetooth LE Star Topology
	In Bluetooth LE a central is assumed to be less constrained than a		In Bluetooth LE a central is assumed to be less constrained than a
	skipping to change at page 6, line 6 ¶		skipping to change at page 6, line 15 ¶
	2.4. Bluetooth LE packets sizes and MTU		2.4. Bluetooth LE packets sizes and MTU
	Optimal MTU defined for L2CAP fixed channels over Bluetooth LE is 27		Optimal MTU defined for L2CAP fixed channels over Bluetooth LE is 27
	bytes including the L2CAP header of four bytes. Default MTU for		bytes including the L2CAP header of four bytes. Default MTU for
	Bluetooth LE is hence defined to be 27 bytes. Therefore, excluding		Bluetooth LE is hence defined to be 27 bytes. Therefore, excluding
	L2CAP header of four bytes, protocol data unit (PDU) size of 23 bytes		L2CAP header of four bytes, protocol data unit (PDU) size of 23 bytes
	is available for upper layers. In order to be able to transmit IPv6		is available for upper layers. In order to be able to transmit IPv6
	packets of 1280 bytes or larger, link layer fragmentation and		packets of 1280 bytes or larger, link layer fragmentation and
	reassembly solution is provided by the L2CAP layer. The IPSP defines		reassembly solution is provided by the L2CAP layer. The IPSP defines
	means for negotiating up a link-layer connection that provides MTU of		means for negotiating up a link-layer connection that provides MTU of
	1280 bytes or higher for the IPv6 layer [IPSP].		1280 bytes or higher for the IPv6 layer [IPSP]. The link-layer MTU
			is negotiated separately for each direction. Implementations that
			require single link-layer MTU value SHALL use the smallest of the
			possibly different MTU values.
	3. Specification of IPv6 over Bluetooth Low Energy		3. Specification of IPv6 over Bluetooth Low Energy
	Before any IP-layer communications can take place over Bluetooth LE,		Before any IP-layer communications can take place over Bluetooth LE,
	Bluetooth LE enabled nodes such as 6LNs and 6LBRs have to find each		Bluetooth LE enabled nodes such as 6LNs and 6LBRs have to find each
	other and establish a suitable link-layer connection. The discovery		other and establish a suitable link-layer connection. The discovery
	and Bluetooth LE connection setup procedures are documented by		and Bluetooth LE connection setup procedures are documented by
	Bluetooth SIG in the IPSP specification [IPSP], and hence are out of		Bluetooth SIG in the IPSP specification [IPSP], and hence are out of
	scope of this document. The IPSP depends on Bluetooth version 4.1,		scope of this document. The IPSP depends on Bluetooth version 4.1,
	and hence both Bluetooth version 4.1 or newer and IPSP are required		and hence both Bluetooth version 4.1 or newer and IPSP are required
	skipping to change at page 6, line 39 ¶		skipping to change at page 6, line 51 ¶
	that the former supports both star and mesh topology (and requires a		that the former supports both star and mesh topology (and requires a
	routing protocol), whereas Bluetooth LE does not currently support		routing protocol), whereas Bluetooth LE does not currently support
	the formation of multihop networks at the link layer.		the formation of multihop networks at the link layer.
	3.1. Protocol stack		3.1. Protocol stack
	Figure 3 illustrates IPv6 over Bluetooth LE stack including the		Figure 3 illustrates IPv6 over Bluetooth LE stack including the
	Internet Protocol Support Service. UDP and TCP are provided as		Internet Protocol Support Service. UDP and TCP are provided as
	examples of transport protocols, but the stack can be used by any		examples of transport protocols, but the stack can be used by any
	other upper layer protocol capable of running atop of IPv6. The		other upper layer protocol capable of running atop of IPv6. The
	6LoWPAN runs on top of Bluetooth LE L2CAP layer.		6LoWPAN layer runs on top of Bluetooth LE L2CAP layer.
	+---------+ +----------------------------+		+---------+ +----------------------------+
	| IPSS | | UDP/TCP/other |		| IPSS | | UDP/TCP/other |
	+---------+ +----------------------------+		+---------+ +----------------------------+
	| GATT | | IPv6 |		| GATT | | IPv6 |
	+---------+ +----------------------------+		+---------+ +----------------------------+
	| ATT | | 6LoWPAN adapted to LE |		| ATT | | 6LoWPAN for Bluetooth LE |
	+---------+--+----------------------------+		+---------+--+----------------------------+
	| Bluetooth LE L2CAP |		| Bluetooth LE L2CAP |
	- - +-----------------------------------------+- - - HCI		- - +-----------------------------------------+- - - HCI
	| Bluetooth LE Link Layer |		| Bluetooth LE Link Layer |
	+-----------------------------------------+		+-----------------------------------------+
	| Bluetooth LE Physical |		| Bluetooth LE Physical |
	+-----------------------------------------+		+-----------------------------------------+
	Figure 3: IPv6 over Bluetooth LE Stack		Figure 3: IPv6 over Bluetooth LE Stack
	skipping to change at page 7, line 41 ¶		skipping to change at page 7, line 41 ¶
	In the case of Bluetooth LE, 6LoWPAN layer is adapted to support		In the case of Bluetooth LE, 6LoWPAN layer is adapted to support
	transmission of IPv6 packets over Bluetooth LE. The IPSP defines all		transmission of IPv6 packets over Bluetooth LE. The IPSP defines all
	steps required for setting up the Bluetooth LE connection over which		steps required for setting up the Bluetooth LE connection over which
	6LoWPAN can function [IPSP], including handling the link-layer		6LoWPAN can function [IPSP], including handling the link-layer
	fragmentation required on Bluetooth LE, as described in Section 2.4.		fragmentation required on Bluetooth LE, as described in Section 2.4.
	This specification also assumes the IPv6 header compression format		This specification also assumes the IPv6 header compression format
	specified in RFC 6282 is used [RFC6282]. It is also assumed that the		specified in RFC 6282 is used [RFC6282]. It is also assumed that the
	IPv6 payload length can be inferred from the L2CAP header length and		IPv6 payload length can be inferred from the L2CAP header length and
	the IID value inferred from the link-layer address with help of		the IID value inferred from the link-layer address with help of
	Neighbor Cache, if elided from compressed packet.		Neighbor Cache, if elided from compressed packet header.
	The Bluetooth LE link between two communicating nodes can be		Bluetooth LE connections used to build a star topology are point-to-
	considered to be a point-to-point or point-to-multipoint link. When		point in nature, as Bluetooth broadcast features are not used for
	one of the communicating nodes is simultaneously connected to		IPv6 over Bluetooth LE. 6LN-to-6LN communications, e.g. using link-
	multiple nodes, the link can be viewed as a point-to-multipoint link		local addresses, need to be bridged by the 6LBR. The 6LBR ensures
	from the particular node point of view. However, due to Bluetooth LE		address collisions do not occur (see Section 3.2.2).
	star topology, each branch of the star is considered to be an
	individual link and thus only two nodes can directly talk to each
	other. Node-to-node communications, e.g. using link-local addresses,
	need to be bridged by the 6LBR. The 6LBR ensures address collisions
	do not occur (see Section 3.2.2).
	After the peripheral and central have connected at the Bluetooth LE		After the peripheral and central have connected at the Bluetooth LE
	level, the link can be considered up and IPv6 address configuration		level, the link can be considered up and IPv6 address configuration
	and transmission can begin.		and transmission can begin.
	3.2.1. Stateless address autoconfiguration		3.2.1. Stateless address autoconfiguration
	A Bluetooth LE 6LN performs stateless address autoconfiguration as		A Bluetooth LE 6LN performs stateless address autoconfiguration as
	per RFC 4862 [RFC4862]. A 64-bit Interface identifier (IID) for a		per RFC 4862 [RFC4862]. A 64-bit Interface identifier (IID) for a
	Bluetooth LE interface MAY be formed by utilizing the 48-bit		Bluetooth LE interface MAY be formed by utilizing the 48-bit
	skipping to change at page 9, line 13 ¶		skipping to change at page 9, line 8 ¶
	including the mesh topology. Bluetooth LE does not support mesh		including the mesh topology. Bluetooth LE does not support mesh
	networks and hence only those aspects that apply to a star topology		networks and hence only those aspects that apply to a star topology
	are considered.		are considered.
	The following aspects of the Neighbor Discovery optimizations		The following aspects of the Neighbor Discovery optimizations
	[RFC6775] are applicable to Bluetooth LE 6LNs:		[RFC6775] are applicable to Bluetooth LE 6LNs:
	1. A Bluetooth LE 6LN MUST register its addresses with the 6LBR by		1. A Bluetooth LE 6LN MUST register its addresses with the 6LBR by
	sending a Neighbor Solicitation (NS) message with the Address		sending a Neighbor Solicitation (NS) message with the Address
	Registration Option (ARO) and process the Neighbor Advertisement (NA)		Registration Option (ARO) and process the Neighbor Advertisement (NA)
	accordingly. The NS with the ARO option SHOULD be sent irrespective		accordingly. The NS with the ARO option MUST be sent irrespective of
	of the method used to generate the IID. The 6LN MUST register only		the method used to generate the IID. The 6LN MUST register only one
	one IPv6 address per IPv6 prefix available on a link.		IPv6 address per IPv6 prefix available on a link.
	2. For sending Router Solicitations and processing Router		2. For sending Router Solicitations and processing Router
	Advertisements the Bluetooth LE 6LNs MUST, respectively, follow		Advertisements the Bluetooth LE 6LNs MUST, respectively, follow
	Sections 5.3 and 5.4 of the [RFC6775].		Sections 5.3 and 5.4 of the [RFC6775].
	3.2.3. Header compression		3.2.3. Header compression
	Header compression as defined in RFC 6282 [RFC6282], which specifies		Header compression as defined in RFC 6282 [RFC6282], which specifies
	the compression format for IPv6 datagrams on top of IEEE 802.15.4, is		the compression format for IPv6 datagrams on top of IEEE 802.15.4, is
	REQUIRED in this document as the basis for IPv6 header compression on		REQUIRED in this document as the basis for IPv6 header compression on
	skipping to change at page 9, line 39 ¶		skipping to change at page 9, line 34 ¶
	The Bluetooth LE's star topology structure and ARO can be exploited		The Bluetooth LE's star topology structure and ARO can be exploited
	in order to provide a mechanism for IID compression. The following		in order to provide a mechanism for IID compression. The following
	text describes the principles of IPv6 address compression on top of		text describes the principles of IPv6 address compression on top of
	Bluetooth LE.		Bluetooth LE.
	The ARO option requires use of EUI-64 identifier [RFC6775]. In the		The ARO option requires use of EUI-64 identifier [RFC6775]. In the
	case of Bluetooth LE, the field SHALL be filled with the 48-bit		case of Bluetooth LE, the field SHALL be filled with the 48-bit
	device address used by the Bluetooth LE node converted into 64-bit		device address used by the Bluetooth LE node converted into 64-bit
	Modified EUI-64 format [RFC4291].		Modified EUI-64 format [RFC4291].
			To enable efficient header compression, the 6LBR MUST include 6LoWPAN
			Context Option (6CO) [RFC6775] for all prefixes the 6LBR advertises
			in Router Advertisements for use in stateless address
			autoconfiguration.
	When a 6LN is sending a packet to or through a 6LBR, it MUST fully		When a 6LN is sending a packet to or through a 6LBR, it MUST fully
	elide the source address if the source IPv6 address is currently		elide the source address it has registered with ARO to the 6LBR for
	registed with ARO to the 6LBR and the 6LN has registered only one		the indicated prefix. That is, if SAC=0 and SAM=11 the 6LN MUST have
	address for the indicated prefix. That is, if SAC=0 and SAM=11 the		registered the source link-local IPv6 address it is using using ARO,
	6LN MUST have registered the source link-local IPv6 address it is		and if SAC=1 and SAM=11 the 6LN MUST have registered the source IPv6
	using using ARO, and if SAC=1 and SAM=11 the 6LN MUST have registered		address with the prefix related to compression context identified
	the source IPv6 address with the prefix related to compression		with Context Identifier Extension. The destination IPv6 address MUST
	context identified with Context Identifier Extension. The		be fully elided if the destination address is the same address to
	destination IPv6 address MUST be fully elided if the destination		which the 6LN has succesfully registered its source IPv6 address with
	address is the same address to which the 6LN has succesfully		ARO (set DAC=0, DAM=11). The destination IPv6 address MUST be fully
	registered its source IPv6 address with ARO (set DAC=0, DAM=11). The		or partially elided if context has been set up for the destination
	destination IPv6 address MUST be fully or partially elided if the		address. For example, DAC=0 and DAM=01 when destination prefix is
	destination address has prefix for which context has been set up, for		link-local, and DAC=1 and DAM=01 with Context Identifier Extension if
	example, DAC=0 and DAM=01 when destination is link-local, and DAC=1		compression context has been configured for the used destination
	and DAM=01 with Context Identifier Extension if compression context		prefix.
	has been configured for the used destination.
	When a 6LBR is transmitting packets to 6LN, it MUST fully elide the		When a 6LBR is transmitting packets to 6LN, it MUST fully elide the
	source IID if the source IPv6 address is the one 6LN has used to		source IID if the source IPv6 address is the one 6LN has used to
	register its address with ARO (set SAC=0, SAM=11), and it MUST elide		register its address with ARO (set SAC=0, SAM=11), and it MUST elide
	the source prefix or address if a compression context related to the		the source prefix or address if a compression context related to the
	IPv6 source address has been set up. The 6LBR also MUST elide the		IPv6 source address has been set up. The 6LBR also MUST elide the
	destination IPv6 address if it is currently registered by the 6LN		destination IPv6 address registered by the 6LN with ARO and thus 6LN
	with ARO and thus 6LN can determine it based on indication of link-		can determine it based on indication of link-local prefix (DAC=0) or
	local prefix (DAC=0) or indication of other prefix (DAC=1 with		indication of other prefix (DAC=1 with Context Identifier Extension).
	Context Identifier Extension).
	3.2.3.1. Remote destination example		3.2.3.1. Remote destination example
	When a 6LN transmits an IPv6 packet to a remote destination using		When a 6LN transmits an IPv6 packet to a remote destination using
	global Unicast IPv6 addresses, if a context is defined for the prefix		global Unicast IPv6 addresses, if a context is defined for the 6LN's
	of the 6LNs global IPv6 address, the 6LN has to indicate this context		global IPv6 address, the 6LN has to indicate this context in the
	in the corresponding source fields of the compressed IPv6 header as		corresponding source fields of the compressed IPv6 header as per
	per Section 3.1 of RFC 6282 [RFC6282], and has to elide the IPv6		Section 3.1 of RFC 6282 [RFC6282], and has to elide the full IPv6
	source address previously registered with ARO. For this, the 6LN		source address previously registered with ARO. For this, the 6LN
	MUST use the following settings in the IPv6 compressed header: CID=1,		MUST use the following settings in the IPv6 compressed header: CID=1,
	SAC=1, SAM=11. In this case, the 6LBR can infer the elided IPv6		SAC=1, SAM=11. In this case, the 6LBR can infer the elided IPv6
	source address since 1) the 6LBR has previously assigned the prefix		source address since 1) the 6LBR has previously assigned the prefix
	to the 6LNs; and 2) the 6LBR maintains a Neighbor Cache that relates		to the 6LNs; and 2) the 6LBR maintains a Neighbor Cache that relates
	the Device Address and the IID the device has registered with ARO.		the Device Address and the IID the device has registered with ARO.
	If a context is defined for the IPv6 destination address, the 6LN has		If a context is defined for the IPv6 destination address, the 6LN has
	to also indicate this context in the corresponding destination fields		to also indicate this context in the corresponding destination fields
	of the compressed IPv6 header, and elide the prefix of the		of the compressed IPv6 header, and elide the prefix of or the full
	destination IPv6 address. For this, the 6LN MUST set the DAM field		destination IPv6 address. For this, the 6LN MUST set the DAM field
	of the compressed IPv6 header as DAM=01 (if the context covers a		of the compressed IPv6 header as DAM=01 (if the context covers a
	64-bit prefix) or as DAM=11 (if the context covers a full, 128-bit		64-bit prefix) or as DAM=11 (if the context covers a full, 128-bit
	address). CID and DAC MUST be set to CID=1 and DAC=1. Note that		address). CID and DAC MUST be set to CID=1 and DAC=1. Note that
	when a context is defined for the IPv6 destination address, the 6LBR		when a context is defined for the IPv6 destination address, the 6LBR
	can infer the elided destination prefix by using the context.		can infer the elided destination prefix by using the context.
	When a 6LBR receives an IPv6 packet sent by a remote node outside the		When a 6LBR receives an IPv6 packet sent by a remote node outside the
	Bluetooth LE network, and the destination of the packet is a 6LN, if		Bluetooth LE network, and the destination of the packet is a 6LN, if
	a context is defined for the prefix of the 6LN's global IPv6 address,		a context is defined for the prefix of the 6LN's global IPv6 address,
	the 6LBR has to indicate this context in the corresponding		the 6LBR has to indicate this context in the corresponding
	destination fields of the compressed IPv6 header. The 6LBR has to		destination fields of the compressed IPv6 header. The 6LBR has to
	elide the IPv6 destination address of the packet before forwarding		elide the IPv6 destination address of the packet before forwarding
	it, if the IPv6 destination address is inferable by the 6LN. For		it, if the IPv6 destination address is inferable by the 6LN. For
	this, the 6LBR will set the DAM field of the IPv6 compressed header		this, the 6LBR will set the DAM field of the IPv6 compressed header
	as DAM=11. CID and DAC needs to be set to CID=1 and DAC=1. If a		as DAM=11. CID and DAC needs to be set to CID=1 and DAC=1. If a
	context is defined for the prefix of the IPv6 source address, the		context is defined for the IPv6 source address, the 6LBR needs to
	6LBR needs to indicate this context in the source fields of the		indicate this context in the source fields of the compressed IPv6
	compressed IPv6 header, and elide that prefix as well. For this, the		header, and elide that prefix as well. For this, the 6LBR needs to
	6LBR needs to set the SAM field of the IPv6 compressed header as		set the SAM field of the IPv6 compressed header as SAM=01 (if the
	SAM=01 (if the context covers a 64-bit prefix) or SAM=11 (if the		context covers a 64-bit prefix) or SAM=11 (if the context covers a
	context covers a full, 128-bit address). CID and SAC are to be set		full, 128-bit address). CID and SAC are to be set to CID=1 and
	to CID=1 and SAC=1.		SAC=1.
	3.2.4. Unicast and Multicast address mapping		3.2.4. Unicast and Multicast address mapping
	The Bluetooth LE link layer does not support multicast. Hence		The Bluetooth LE link layer does not support multicast. Hence
	traffic is always unicast between two Bluetooth LE nodes. Even in		traffic is always unicast between two Bluetooth LE nodes. Even in
	the case where a 6LBR is attached to multiple 6LNs, the 6LBR cannot		the case where a 6LBR is attached to multiple 6LNs, the 6LBR cannot
	do a multicast to all the connected 6LNs. If the 6LBR needs to send		do a multicast to all the connected 6LNs. If the 6LBR needs to send
	a multicast packet to all its 6LNs, it has to replicate the packet		a multicast packet to all its 6LNs, it has to replicate the packet
	and unicast it on each link. However, this may not be energy-		and unicast it on each link. However, this may not be energy-
	efficient and particular care must be taken if the master is battery-		efficient and particular care must be taken if the master is battery-
	powered. In the opposite direction, a 6LN can only transmit data to		powered. In the opposite direction, a 6LN always has to send packets
	a single destination (i.e. the 6LBR). Hence, when a 6LN needs to		to or through 6LBR. Hence, when a 6LN needs to transmit an IPv6
	transmit an IPv6 multicast packet, the 6LN will unicast the		multicast packet, the 6LN will unicast the corresponding Bluetooth LE
	corresponding Bluetooth LE packet to the 6LBR. The 6LBR will then		packet to the 6LBR. The 6LBR will then forward the multicast packet
	forward the multicast packet to other 6LNs. To avoid excess unwanted		to other 6LNs. To avoid excess of unwanted multicast traffic being
	multicast traffic being sent to 6LNs, the 6LBR SHOULD implement MLD		sent to 6LNs, the 6LBR SHOULD implement MLD Snooping feature
	Snooping feature [RFC4541].		[RFC4541].
	3.3. Internet connectivity scenarios		3.3. Internet connectivity scenarios
	In a typical scenario, the Bluetooth LE network is connected to the		In a typical scenario, the Bluetooth LE network is connected to the
	Internet as shown in the Figure 5.		Internet as shown in the Figure 5.
	6LN		6LN
	\ ____________		\ ____________
	\ / \		\ / \
	6LN ---- 6LBR ----- | Internet |		6LN ---- 6LBR ----- | Internet |
End of changes. 25 change blocks.
	89 lines changed or deleted		92 lines changed or added
This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/