6Lo Working Group Y. Choi, Ed.
Internet-Draft Y-G. Hong
Intended status: Standards Track ETRI
Expires: May 9, 2019 J-S. Youn
Dongeui Univ
D-K. Kim
KNU
J-H. Choi
Samsung Electronics Co.,
November 5, 2018
Transmission of IPv6 Packets over Near Field Communication
draft-ietf-6lo-nfc-12
Abstract
Near field communication (NFC) is a set of standards for smartphones
and portable devices to establish radio communication with each other
by touching them together or bringing them into proximity, usually no
more than 10 cm. NFC standards cover communications protocols and
data exchange formats, and are based on existing radio-frequency
identification (RFID) standards including ISO/IEC 14443 and FeliCa.
The standards include ISO/IEC 18092 and those defined by the NFC
Forum. The NFC technology has been widely implemented and available
in mobile phones, laptop computers, and many other devices. This
document describes how IPv6 is transmitted over NFC using 6LowPAN
techniques.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 9, 2019.
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Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 3
3. Overview of Near Field Communication Technology . . . . . . . 4
3.1. Peer-to-peer Mode of NFC . . . . . . . . . . . . . . . . 4
3.2. Protocol Stacks of NFC . . . . . . . . . . . . . . . . . 4
3.3. NFC-enabled Device Addressing . . . . . . . . . . . . . . 6
3.4. MTU of NFC Link Layer . . . . . . . . . . . . . . . . . . 6
4. Specification of IPv6 over NFC . . . . . . . . . . . . . . . 7
4.1. Protocol Stacks . . . . . . . . . . . . . . . . . . . . . 7
4.2. Link Model . . . . . . . . . . . . . . . . . . . . . . . 8
4.3. Stateless Address Autoconfiguration . . . . . . . . . . . 9
4.4. IPv6 Link Local Address . . . . . . . . . . . . . . . . . 9
4.5. Neighbor Discovery . . . . . . . . . . . . . . . . . . . 10
4.6. Dispatch Header . . . . . . . . . . . . . . . . . . . . . 11
4.7. Header Compression . . . . . . . . . . . . . . . . . . . 11
4.8. Fragmentation and Reassembly . . . . . . . . . . . . . . 12
4.9. Unicast and Multicast Address Mapping . . . . . . . . . . 12
5. Internet Connectivity Scenarios . . . . . . . . . . . . . . . 13
5.1. NFC-enabled Device Connected to the Internet . . . . . . 13
5.2. Isolated NFC-enabled Device Network . . . . . . . . . . . 14
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
7. Security Considerations . . . . . . . . . . . . . . . . . . . 14
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Normative References . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
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1. Introduction
NFC is a set of short-range wireless technologies, typically
requiring a distance of 10 cm or less. NFC operates at 13.56 MHz on
ISO/IEC 18000-3 air interface and at rates ranging from 106 kbit/s to
424 kbit/s [ECMA-340]. NFC always involves an initiator and a
target; the initiator actively generates an RF field that can power a
passive target. This enables NFC targets to take very simple form
factors such as tags, stickers, key fobs, or cards that do not
require batteries. NFC peer-to-peer communication is possible,
provided both devices are powered. NFC builds upon RFID systems by
allowing two-way communication between endpoints, where earlier
systems such as contactless smart cards were one-way only. It has
been used in devices such as mobile phones, running Android operating
system, named with a feature called "Android Beam". In addition, it
is expected for the other mobile phones, running the other operating
systems (e.g., iOS, etc.) to be equipped with NFC technology in the
near future.
Considering the potential for exponential growth in the number of
heterogeneous air interface technologies, NFC would be widely used as
one of the other air interface technologies, such as Bluetooth Low
Energy (BT-LE), Wi-Fi, and so on. Each of the heterogeneous air
interface technologies has its own characteristics, which cannot be
covered by the other technologies, so various kinds of air interface
technologies would co-exist together. Therefore, it is required for
them to communicate with each other. NFC also has the strongest
ability (e.g., secure communication distance of 10 cm) to prevent a
third party from attacking privacy.
When the number of devices and things having different air interface
technologies communicate with each other, IPv6 is an ideal internet
protocols owing to its large address space. Also, NFC would be one
of the endpoints using IPv6. Therefore, this document describes how
IPv6 is transmitted over NFC using 6LoWPAN techniques.
[RFC4944] specifies the transmission of IPv6 over IEEE 802.15.4. The
NFC link also has similar characteristics to that of IEEE 802.15.4.
Many of the mechanisms defined in [RFC4944] can be applied to the
transmission of IPv6 on NFC links. This document specifies the
details of IPv6 transmission over NFC links.
2. Conventions and Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
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14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Overview of Near Field Communication Technology
NFC technology enables simple and safe two-way interactions between
electronic devices, allowing consumers to perform contactless
transactions, access digital content, and connect electronic devices
with a single touch. NFC complements many popular consumer level
wireless technologies, by utilizing the key elements in existing
standards for contactless card technology (ISO/IEC 14443 A&B and
JIS-X 6319-4). NFC can be compatible with existing contactless card
infrastructure and it enables a consumer to utilize one device across
different systems.
Extending the capability of contactless card technology, NFC also
enables devices to share information at a distance that is less than
10 cm with a maximum communication speed of 424 kbps. Users can
share business cards, make transactions, access information from a
smart poster or provide credentials for access control systems with a
simple touch.
NFC's bidirectional communication ability is ideal for establishing
connections with other technologies by the simplicity of touch. In
addition to the easy connection and quick transactions, simple data
sharing is also available.
3.1. Peer-to-peer Mode of NFC
NFC-enabled devices are unique in that they can support three modes
of operation: card emulation, peer-to-peer, and reader/writer. Peer-
to-peer mode enables two NFC-enabled devices to communicate with each
other to exchange information and share files, so that users of NFC-
enabled devices can quickly share contact information and other files
with a touch. Therefore, an NFC-enabled device can securely send
IPv6 packets to any corresponding node on the Internet when an NFC-
enabled gateway is linked to the Internet.
3.2. Protocol Stacks of NFC
IP can use the services provided by the Logical Link Control Protocol
(LLCP) in the NFC stack to provide reliable, two-way transport of
information between the peer devices. Figure 1 depicts the NFC P2P
protocol stack with IPv6 bindings to LLCP.
For data communication in IPv6 over NFC, an IPv6 packet MUST be
passed down to LLCP of NFC and transported to an Information (I) and
an Unnumbered Information (UI) Field in Protocol Data Unit (PDU) of
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LLCP of the NFC-enabled peer device. LLCP does not support
fragmentation and reassembly. For IPv6 addressing or address
configuration, LLCP MUST provide related information, such as link
layer addresses, to its upper layer. The LLCP to IPv6 protocol
binding MUST transfer the SSAP and DSAP value to the IPv6 over NFC
protocol. SSAP stands for Source Service Access Point, which is a
6-bit value meaning a kind of Logical Link Control (LLC) address,
while DSAP means an LLC address of the destination NFC-enabled
device.
| |
| | Application Layer
| Upper Layer Protocols | Transport Layer
| | Network Layer
| | |
+----------------------------------------+ <------------------
| IPv6-LLCP Binding | |
+----------------------------------------+ NFC
| | Logical Link
| Logical Link Control Protocol | Layer
| (LLCP) | |
+----------------------------------------+ <------------------
| | |
| Activities | |
| Digital Protocol | NFC
| | Physical
+----------------------------------------+ Layer
| | |
| RF Analog | |
| | |
+----------------------------------------+ <------------------
Figure 1: Protocol Stacks of NFC
The LLCP consists of Logical Link Control (LLC) and MAC Mapping. The
MAC Mapping integrates an existing RF protocol into the LLCP
architecture. The LLC contains three components, such as Link
Management, Connection-oriented Transport, and Connection-less
Transport. The Link Management component is responsible for
serializing all connection-oriented and connection-less LLC PDU
(Protocol Data Unit) exchanges and for aggregation and disaggregation
of small PDUs. This component also guarantees asynchronous balanced
mode communication and provides link status supervision by performing
the symmetry procedure. The Connection-oriented Transport component
is responsible for maintaining all connection-oriented data exchanges
including connection set-up and termination. The Connectionless
Transport component is responsible for handling unacknowledged data
exchanges.
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3.3. NFC-enabled Device Addressing
According to NFC Logical Link Control Protocol v1.3 [LLCP-1.3], NFC-
enabled devices have two types of 6-bit addresses (i.e., SSAP and
DSAP) to identify service access points. The several service access
points can be installed on a NFC device. However, the SSAP and DSAP
can be used as identifiers for NFC link connections with the IPv6
over NFC adaptation layer. Therefore, the SSAP can be used to
generate an IPv6 interface identifier. Address values between 00h
and 0Fh of SSAP and DSAP are reserved for identifying the well-known
service access points, which are defined in the NFC Forum Assigned
Numbers Register. Address values between 10h and 1Fh SHALL be
assigned by the local LLC to services registered by local service
environment. In addition, address values between 20h and 3Fh SHALL
be assigned by the local LLC as a result of an upper layer service
request. Therefore, the address values between 20h and 3Fh can be
used for generating IPv6 interface identifiers.
3.4. MTU of NFC Link Layer
As mentioned in Section 3.2, an IPv6 packet MUST be passed down to
LLCP of NFC and transported to an Unnumbered Information Protocol
Data Unit (UI PDU) and an Information Field in Protocol Data Unit (I
PDU) of LLCP of the NFC-enabled peer device.
The information field of an I PDU contains a single service data
unit. The maximum number of octets in the information field is
determined by the Maximum Information Unit (MIU) for the data link
connection. The default value of the MIU for I PDUs is 128 octets.
The local and remote LLCs each establish and maintain distinct MIU
values for each data link connection endpoint. Also, an LLC MAY
announce a larger MIU for a data link connection by transmitting an
MIUX extension parameter within the information field. If no MIUX
parameter is transmitted, the default MIU value of 128 MUST be used.
Otherwise, the MTU size in NFC LLCP MUST be calculated from the MIU
value as follows:
MIU = 128 + MIUX.
According to [LLCP-1.3], Figure 2 shows an example of the MIUX
parameter TLV. Each of TLV Type and TLV Length field is 1 byte, and
TLV Value field is 2 bytes.
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0 0 1 2 3
0 8 6 2 1
+--------+--------+----------------+
| Type | Length | Value |
+--------+--------+----+-----------+
|00000010|00000010|1011| MIUX |
+--------+--------+----+-----------+
| <-------> |
0x000 ~ 0x7FF
Figure 2: Example of MIUX Parameter TLV
When the MIUX parameter is encoded as a TLV option, the TLV Type
field MUST be 0x02 and the TLV Length field MUST be 0x02. The MIUX
parameter MUST be encoded into the least significant 11 bits of the
TLV Value field. The unused bits in the TLV Value field MUST be set
to zero by the sender and ignored by the receiver. A maximum value
of the TLV Value field can be 0x7FF, and a maximum size of the MTU in
NFC LLCP is 2176 bytes including the 128 byte default of MIU.
4. Specification of IPv6 over NFC
NFC technology also has considerations and requirements owing to low
power consumption and allowed protocol overhead. 6LoWPAN standards
[RFC4944], [RFC6775], and [RFC6282] provide useful functionality for
reducing overhead which can be applied to NFC. This functionality
consists of link-local IPv6 addresses and stateless IPv6 address
auto-configuration (see Section 4.3), Neighbor Discovery (see
Section 4.5) and header compression (see Section 4.7).
4.1. Protocol Stacks
Figure 3 illustrates IPv6 over NFC. Upper layer protocols can be
transport layer protocols (TCP and UDP), application layer protocols,
and others capable running on top of IPv6.
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| | Transport &
| Upper Layer Protocols | Application Layer
+----------------------------------------+ <------------------
| | |
| IPv6 | |
| | Network
+----------------------------------------+ Layer
| Adaptation Layer for IPv6 over NFC | |
+----------------------------------------+ <------------------
| IPv6-LLCP Binding |
| Logical Link Control Protocol | NFC Link Layer
| (LLCP) | |
+----------------------------------------+ <------------------
| | |
| Activities | NFC
| Digital Protocol | Physical Layer
| RF Analog | |
| | |
+----------------------------------------+ <------------------
Figure 3: Protocol Stacks for IPv6 over NFC
The adaptation layer for IPv6 over NFC SHALL support neighbor
discovery, stateless address auto-configuration, header compression,
and fragmentation & reassembly.
4.2. Link Model
In the case of BT-LE, the Logical Link Control and Adaptation
Protocol (L2CAP) supports fragmentation and reassembly (FAR)
functionality; therefore, the adaptation layer for IPv6 over BT-LE
does not have to conduct the FAR procedure. The NFC LLCP, in
contrast, does not support the FAR functionality, so IPv6 over NFC
needs to consider the FAR functionality, defined in [RFC4944].
However, the MTU on an NFC link can be configured in a connection
procedure and extended enough to fit the MTU of IPv6 packet (see
Section 4.8).
This document does NOT RECOMMEND using FAR over NFC link due to
simplicity of the protocol and implementation. In addition, the
implementation for this specification SHOULD use MIUX extension to
communicate the MTU of the link to the peer as defined in
Section 3.4.
The NFC link between two communicating devices is considered to be a
point-to-point link only. Unlike in BT-LE, an NFC link does not
support a star topology or mesh network topology but only direct
connections between two devices. Furthermore, the NFC link layer
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does not support packet forwarding in link layer. Due to this
characteristics, 6LoWPAN functionalities, such as addressing and
auto-configuration, and header compression, need to be specialized
into IPv6 over NFC.
4.3. Stateless Address Autoconfiguration
An NFC-enabled device (i.e., 6LN) performs stateless address
autoconfiguration as per [RFC4862]. A 64-bit Interface identifier
(IID) for an NFC interface is formed by utilizing the 6-bit NFC LLCP
address (see Section 3.3). In the viewpoint of address
configuration, such an IID SHOULD guarantee a stable IPv6 address
because each data link connection is uniquely identified by the pair
of DSAP and SSAP included in the header of each LLC PDU in NFC.
Following the guidance of [RFC7136], interface identifiers of all
unicast addresses for NFC-enabled devices are 64 bits long and
constructed by using the generation algorithm of random (but stable)
identifier (RID) [RFC7217] (see Figure 4).
0 1 3 4 6
0 6 2 8 3
+---------+---------+---------+---------+
| Random (but stable) Identifier (RID) |
+---------+---------+---------+---------+
Figure 4: IID from NFC-enabled device
The RID is an output which MAY be created by the algorithm, F() with
input parameters. One of the parameters is Net_IFace, and NFC Link
Layer address (i.e., SSAP) MAY be a source of the NetIFace parameter.
The 6-bit address of SSAP of NFC is easy and short to be targeted by
attacks of third party (e.g., address scanning). The F() can provide
secured and stable IIDs for NFC-enabled devices. In addition, an
optional parameter, Network_ID MAY be used to increase the randomness
of the generated IID.
4.4. IPv6 Link Local Address
Only if the NFC-enabled device address is known to be a public
address, the "Universal/Local" bit be set to 1. The IPv6 link-local
address for an NFC-enabled device is formed by appending the IID, to
the prefix FE80::/64, as depicted in Figure 5.
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0 0 0 1
0 1 6 2
0 0 4 7
+----------+------------------+----------------------------+
|1111111010| zeros | Interface Identifier |
+----------+------------------+----------------------------+
| |
| <---------------------- 128 bits ----------------------> |
| |
Figure 5: IPv6 link-local address in NFC
The tool for a 6LBR to obtain an IPv6 prefix for numbering the NFC
network is can be accomplished via DHCPv6 Prefix Delegation
([RFC3633]).
4.5. Neighbor Discovery
Neighbor Discovery Optimization for 6LoWPANs ([RFC6775]) describes
the neighbor discovery approach in several 6LoWPAN topologies, such
as mesh topology. NFC does not support a complicated mesh topology
but only a simple multi-hop network topology or directly connected
peer-to-peer network. Therefore, the following aspects of RFC 6775
are applicable to NFC:
o When an NFC-enabled device (6LN) is directly connected to a 6LBR,
an NFC 6LN MUST register its address with the 6LBR by sending a
Neighbor Solicitation (NS) message with the Address Registration
Option (ARO) and process the Neighbor Advertisement (NA)
accordingly. In addition, if DHCPv6 is used to assign an address,
Duplicate Address Detection (DAD) MAY not be required.
o When two or more NFC 6LNs(or 6LRs) meet, there MAY be two cases.
One is that they meet with multi-hop connections, and the other is
that they meet within a sigle hop range (e.g., isolated network).
In a case of multi-hops, all of 6LNs, which have two or more
connections with different neighbors, MAY be a router for
6LR/6LBR. In a case that they meet within a single hop and they
have the same properties, any of them can be a router. When the
NFC nodes are not of uniform category (e.g., different MTU, level
of remaining energy, connectivity, etc.), a performance-
outstanding device can become a router. Also, they MUST deliver
their MTU information to neighbors with NFC LLCP protocols during
connection initialization. The router MAY also communicate other
capabilities which is out of scope of this document.
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o For sending Router Solicitations and processing Router
Advertisements, the NFC 6LNs MUST follow Sections 5.3 and 5.4 of
[RFC6775].
o When a NFC device becomes a 6LR or a 6LBR, the NFC device MUST
follow Section 6 and 7 of [RFC6775].
4.6. Dispatch Header
All IPv6-over-NFC encapsulated datagrams are prefixed by an
encapsulation header stack consisting of a Dispatch value followed by
zero or more header fields. The only sequence currently defined for
IPv6-over-NFC is the LOWPAN_IPHC header followed by payload, as
depicted in Figure 6.
+---------------+---------------+--------------+
| IPHC Dispatch | IPHC Header | Payload |
+---------------+---------------+--------------+
Figure 6: A IPv6-over-NFC Encapsulated 6LOWPAN_IPHC Compressed IPv6
Datagram
The dispatch value may be treated as an unstructured namespace. Only
a single pattern is used to represent current IPv6-over-NFC
functionality.
+------------+--------------------+-----------+
| Pattern | Header Type | Reference |
+------------+--------------------+-----------+
| 01 1xxxxx | 6LOWPAN_IPHC | [RFC6282] |
+------------+--------------------+-----------+
Figure 7: Dispatch Values
Other IANA-assigned 6LoWPAN Dispatch values do not apply to this
specification.
4.7. Header Compression
Header compression as defined in [RFC6282], which specifies 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
top of NFC. All headers MUST be compressed according to RFC 6282
encoding formats.
Therefore, IPv6 header compression in [RFC6282] MUST be implemented.
Further, implementations MAY also support Generic Header Compression
(GHC) of [RFC7400].
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If a 16-bit address is required as a short address, it MUST be formed
by padding the 6-bit NFC link-layer (node) address to the left with
zeros as shown in Figure 8.
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Padding(all zeros)| NFC Addr. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8: NFC short address format
4.8. Fragmentation and Reassembly
IPv6-over-NFC fragmentation and reassembly (FAR) for the payloads is
NOT RECOMMENDED in this document as discussed in Section 3.4. The
NFC link connection for IPv6 over NFC MUST be configured with an
equivalent MIU size to fit the MTU of IPv6 Packet. The MIUX value is
0x480 in order to fit the MTU (1280 bytes) of a IPv6 packet if NFC
devices support extension of the MTU. However, if the NFC device
does not support extension, IPv6-over-NFC uses FAR with default MIU
(128 bytes), as defined in [RFC4944].
4.9. Unicast and Multicast Address Mapping
The address resolution procedure for mapping IPv6 non-multicast
addresses into NFC link-layer addresses follows the general
description in Section 7.2 of [RFC4861], unless otherwise specified.
The Source/Target link-layer Address option has the following form
when the addresses are 6-bit NFC link-layer (node) addresses.
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length=1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+- Padding (all zeros) -+
| |
+- +-+-+-+-+-+-+
| | NFC Addr. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 9: Unicast address mapping
Option fields:
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Type:
1: for Source Link-layer address.
2: for Target Link-layer address.
Length:
This is the length of this option (including the type and
length fields) in units of 8 octets. The value of this field
is 1 for 6-bit NFC node addresses.
NFC address:
The 6-bit address in canonical bit order. This is the unicast
address the interface currently responds to.
The NFC Link Layer does not support multicast. Therefore, packets
are always transmitted by unicast between two NFC-enabled devices.
Even in 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 a multicast packet to all its 6LNs, it has to replicate the
packet and unicast it on each link.
5. Internet Connectivity Scenarios
As two typical scenarios, the NFC network can be isolated and
connected to the Internet.
5.1. NFC-enabled Device Connected to the Internet
One of the key applications of using IPv6 over NFC is securely
transmitting IPv6 packets because the RF distance between 6LN and
6LBR is typically within 10 cm. If any third party wants to hack
into the RF between them, it must come to nearly touch them.
Applications can choose which kinds of air interfaces (e.g., BT-LE,
Wi-Fi, NFC, etc.) to send data depending on the characteristics of
the data.
Figure 10 illustrates an example of an NFC-enabled device network
connected to the Internet. The distance between 6LN and 6LBR is
typically 10 cm or less. If there is any laptop computers close to a
user, it will become the a 6LBR. Additionally, when the user mounts
an NFC-enabled air interface adapter (e.g., portable NFC dongle) on
the close laptop PC, the user's NFC-enabled device (6LN) can
communicate with the laptop PC (6LBR) within 10 cm distance.
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************
6LN ------------------- 6LBR -----* Internet *------- CN
| (dis. 10 cm or less) | ************ |
| | |
| <-------- NFC -------> | <----- IPv6 packet ------> |
| (IPv6 over NFC packet) | |
Figure 10: NFC-enabled device network connected to the Internet
Two or more LNs MAY be connected with a 6LBR, but each connection
uses a different subnet. The 6LBR is acting as a router and
forwarding packets between 6LNs and the Internet. Also, the 6LBR
MUST ensure address collisions do not occur and forwards packets sent
by one 6LN to another.
5.2. Isolated NFC-enabled Device Network
In some scenarios, the NFC-enabled device network may transiently be
a simple isolated network as shown in the Figure 11.
6LN ---------------------- 6LR ---------------------- 6LN
| (10 cm or less) | (10 cm or less) |
| | |
| <--------- NFC --------> | <--------- NFC --------> |
| (IPv6 over NFC packet) | (IPv6 over NFC packet) |
Figure 11: Isolated NFC-enabled device network
In mobile phone markets, applications are designed and made by user
developers. They may image interesting applications, where three or
more mobile phones touch or attach each other to accomplish
outstanding performance. In an isolated NFC-enabled device network,
when two or more LRs MAY be connected with each other, and then they
are acting like routers, the 6LR MUST ensure address collisions do
not occur.
6. IANA Considerations
There are no IANA considerations related to this document.
7. Security Considerations
When interface identifiers (IIDs) are generated, devices and users
are required to consider mitigating various threats, such as
correlation of activities over time, location tracking, device-
specific vulnerability exploitation, and address scanning.
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IPv6-over-NFC is, in practice, not used for long-lived links for big
size data transfer or multimedia streaming, but used for extremely
short-lived links (i.e., single touch-based approaches) for ID
verification and mobile payment. This will mitigate the threat of
correlation of activities over time.
IPv6-over-NFC uses an IPv6 interface identifier formed from a "Short
Address" and a set of well-known constant bits (such as padding with
'0's) for the modified EUI-64 format. However, the short address of
NFC link layer (LLC) is not generated as a physically permanent value
but logically generated for each connection. Thus, every single
touch connection can use a different short address of NFC link with
an extremely short-lived link. This can mitigate address scanning as
well as location tracking and device-specific vulnerability
exploitation.
Thus, this document does not RECOMMEND sending NFC packets over the
Internet or any unsecured network.
If there is a compelling reason to send/receive the IPv6-over-NFC
packets over the unsecured network, the deployment SHOULD make sure
that the packets are sent over secured channels. The particular
Security mechanisms are out of scope of this document.
8. Acknowledgements
We are grateful to the members of the IETF 6lo working group.
Michael Richardson, Suresh Krishnan, Pascal Thubert, Carsten Bormann,
Alexandru Petrescu, James Woodyatt, Dave Thaler, Samita Chakrabarti,
and Gabriel Montenegro have provided valuable feedback for this
draft.
9. References
9.1. Normative References
[LLCP-1.3]
"NFC Logical Link Control Protocol version 1.3", NFC Forum
Technical Specification , March 2016.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
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[RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic
Host Configuration Protocol (DHCP) version 6", RFC 3633,
DOI 10.17487/RFC3633, December 2003,
<https://www.rfc-editor.org/info/rfc3633>.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, DOI 10.17487/RFC4291, February
2006, <https://www.rfc-editor.org/info/rfc4291>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007,
<https://www.rfc-editor.org/info/rfc4861>.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862,
DOI 10.17487/RFC4862, September 2007,
<https://www.rfc-editor.org/info/rfc4862>.
[RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler,
"Transmission of IPv6 Packets over IEEE 802.15.4
Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007,
<https://www.rfc-editor.org/info/rfc4944>.
[RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6
Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
DOI 10.17487/RFC6282, September 2011,
<https://www.rfc-editor.org/info/rfc6282>.
[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
Bormann, "Neighbor Discovery Optimization for IPv6 over
Low-Power Wireless Personal Area Networks (6LoWPANs)",
RFC 6775, DOI 10.17487/RFC6775, November 2012,
<https://www.rfc-editor.org/info/rfc6775>.
[RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6
Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136,
February 2014, <https://www.rfc-editor.org/info/rfc7136>.
[RFC7217] Gont, F., "A Method for Generating Semantically Opaque
Interface Identifiers with IPv6 Stateless Address
Autoconfiguration (SLAAC)", RFC 7217,
DOI 10.17487/RFC7217, April 2014,
<https://www.rfc-editor.org/info/rfc7217>.
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[RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for
IPv6 over Low-Power Wireless Personal Area Networks
(6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November
2014, <https://www.rfc-editor.org/info/rfc7400>.
[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>.
9.2. Informative References
[ECMA-340]
"Near Field Communication - Interface and Protocol (NFCIP-
1) 3rd Ed.", ECMA-340 , June 2013.
Authors' Addresses
Younghwan Choi (editor)
Electronics and Telecommunications Research Institute
218 Gajeongno, Yuseung-gu
Daejeon 34129
Korea
Phone: +82 42 860 1429
Email: yhc@etri.re.kr
Yong-Geun Hong
Electronics and Telecommunications Research Institute
161 Gajeong-Dong Yuseung-gu
Daejeon 305-700
Korea
Phone: +82 42 860 6557
Email: yghong@etri.re.kr
Joo-Sang Youn
DONG-EUI University
176 Eomgwangno Busan_jin_gu
Busan 614-714
Korea
Phone: +82 51 890 1993
Email: joosang.youn@gmail.com
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Dongkyun Kim
Kyungpook National University
80 Daehak-ro, Buk-gu
Daegu 702-701
Korea
Phone: +82 53 950 7571
Email: dongkyun@knu.ac.kr
JinHyouk Choi
Samsung Electronics Co.,
129 Samsung-ro, Youngdong-gu
Suwon 447-712
Korea
Phone: +82 2 2254 0114
Email: jinchoe@samsung.com
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