draft-ietf-6lowpan-hc-04.txt   draft-ietf-6lowpan-hc-05.txt 
Network Working Group J. Hui, Ed. Network Working Group J. Hui, Ed.
Internet-Draft Arch Rock Corporation Internet-Draft Arch Rock Corporation
Updates: 4944 (if approved) P. Thubert Updates: 4944 (if approved) P. Thubert
Intended status: Standards Track Cisco Intended status: Standards Track Cisco
Expires: June 11, 2009 December 8, 2008 Expires: January 1, 2010 June 30, 2009
Compression Format for IPv6 Datagrams in 6LoWPAN Networks Compression Format for IPv6 Datagrams in 6LoWPAN Networks
draft-ietf-6lowpan-hc-04 draft-ietf-6lowpan-hc-05
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Abstract Abstract
This document specifies an IPv6 header compression format for IPv6 This document specifies an IPv6 header compression format for IPv6
packet delivery in 6LoWPAN networks. The compression format relies packet delivery in 6LoWPAN networks. The compression format relies
on shared context information to allow compression of arbitrary on shared context to allow compression of arbitrary prefixes. The
prefixes and addresses. This document specifies an interface to an information that is maintained in that shared context is out of
abstract context database but the content and the management of the scope. This document specifies compression of multicast addresses
database are out of scope. This document specifies compression of and a framework for compressing next headers. This framework
multicast addresses and a framework for compressing next headers. specifies UDP compression and is prepared for additional transports.
This framework specifies UDP compression and is prepared for
additional transports.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. IPv6 Header Compression . . . . . . . . . . . . . . . . . . . 4 2. IPv6 Header Compression . . . . . . . . . . . . . . . . . . . 4
2.1. LOWPAN_IPHC Encoding Format . . . . . . . . . . . . . . . 5 2.1. LOWPAN_IPHC Encoding Format . . . . . . . . . . . . . . . 5
2.1.1. Base Format . . . . . . . . . . . . . . . . . . . . . 5 2.1.1. Base Format . . . . . . . . . . . . . . . . . . . . . 5
2.1.2. Context Identifier Extension . . . . . . . . . . . . . 7 2.1.2. Context Identifier Extension . . . . . . . . . . . . . 8
2.2. IPv6 Header Encoding . . . . . . . . . . . . . . . . . . . 8 2.2. IPv6 Header Encoding . . . . . . . . . . . . . . . . . . . 8
2.2.1. Traffic Class and Flow Label Compression . . . . . . . 9 2.2.1. Traffic Class and Flow Label Compression . . . . . . . 8
2.2.2. Stateless Multicast Addresses Compression . . . . . . 10 2.2.2. Stateless Multicast Addresses Compression . . . . . . 10
2.2.3. Stateful Multicast Addresses Compression . . . . . . . 11 2.2.3. Stateful Multicast Addresses Compression . . . . . . . 11
3. IPv6 Next Header Compression . . . . . . . . . . . . . . . . . 11 3. IPv6 Next Header Compression . . . . . . . . . . . . . . . . . 11
3.1. LOWPAN_NHC Format . . . . . . . . . . . . . . . . . . . . 12 3.1. LOWPAN_NHC Format . . . . . . . . . . . . . . . . . . . . 12
3.2. UDP Header Compression . . . . . . . . . . . . . . . . . . 12 3.2. IPv6 Extension Header Compression . . . . . . . . . . . . 12
3.2.1. Compressing UDP ports . . . . . . . . . . . . . . . . 12 3.3. UDP Header Compression . . . . . . . . . . . . . . . . . . 14
3.2.2. Compressing UDP checksum . . . . . . . . . . . . . . . 13 3.3.1. Compressing UDP ports . . . . . . . . . . . . . . . . 14
3.2.3. UDP LOWPAN_NHC Format . . . . . . . . . . . . . . . . 14 3.3.2. Compressing UDP checksum . . . . . . . . . . . . . . . 14
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 3.3.3. UDP LOWPAN_NHC Format . . . . . . . . . . . . . . . . 15
5. Security Considerations . . . . . . . . . . . . . . . . . . . 14 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15 5. Security Considerations . . . . . . . . . . . . . . . . . . . 16
7. Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 7. Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
8.1. Normative References . . . . . . . . . . . . . . . . . . . 16 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
8.2. Informative References . . . . . . . . . . . . . . . . . . 16 8.1. Normative References . . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17 8.2. Informative References . . . . . . . . . . . . . . . . . . 18
Intellectual Property and Copyright Statements . . . . . . . . . . 18 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction 1. Introduction
The [IEEE 802.15.4] standard specifies an MTU of 128 bytes, yielding The [IEEE 802.15.4] standard specifies an MTU of 128 bytes, yielding
about 80 octets of actual MAC payload once security is turned on, on about 80 octets of actual MAC payload once security is turned on, on
a wireless link with a link throughput of 250 kbps or less. The a wireless link with a link throughput of 250 kbps or less. The
6LoWPAN adaptation format [RFC4944] was specified to carry IPv6 6LoWPAN adaptation format [RFC4944] was specified to carry IPv6
datagrams over such constrained links, taking into account limited datagrams over such constrained links, taking into account limited
bandwidth, memory, or energy resources that are expected in bandwidth, memory, or energy resources that are expected in
applications such as Wireless Sensor Networks. [RFC4944] defines a applications such as wireless Sensor Networks. [RFC4944] defines a
Mesh Addressing header to support sub-IP forwarding, a Fragmentation Mesh Addressing header to support sub-IP forwarding, a Fragmentation
header to support the IPv6 minimum MTU requirement [RFC2460], and header to support the IPv6 minimum MTU requirement [RFC2460], and
stateless header compression for IPv6 datagrams (LOWPAN_HC1 and stateless header compression for IPv6 datagrams (LOWPAN_HC1 and
LOWPAN_HC2) to reduce the relatively large IPv6 and UDP headers down LOWPAN_HC2) to reduce the relatively large IPv6 and UDP headers down
to (in the best case) several bytes. to (in the best case) several bytes.
LOWPAN_HC1 and LOWPAN_HC2 are insufficient for most practical uses of LOWPAN_HC1 and LOWPAN_HC2 are insufficient for most practical uses of
6LoWPAN networks. LOWPAN_HC1 is most effective for link-local 6LoWPAN networks. LOWPAN_HC1 is most effective for link-local
unicast communication, where IPv6 addresses carry the link-local unicast communication, where IPv6 addresses carry the link-local
prefix and Interface Identifiers (IID) directly derived from IEEE prefix and an Interface Identifier (IID) directly derived from IEEE
802.15.4 addresses. In this case, both addresses may be completely 802.15.4 addresses. In this case, both addresses may be completely
elided. However, though link-local addresses are commonly used for elided. However, though link local addresses are commonly used for
local protocol interactions such as IPv6 ND [RFC4861], DHCPv6 local protocol interactions such as IPv6 ND [RFC4861], DHCPv6
[RFC3315] or routing protocols, they are not normally used for [RFC3315] or routing protocols, they are usually not used for
application layer data traffic, so the actual value of this application layer data traffic, so the actual value of this
compression mechanism is limited. compression mechanism is limited.
Routable addresses must be used when communicating with devices Routable addresses must be used when communicating with devices
external to the LoWPAN or in a route-over configuration where IP external to the LoWPAN or in a route-over configuration where IP
forwarding occurs within the LoWPAN. For routable addresses, forwarding occurs within the LoWPAN. For routable addresses,
LOWPAN_HC1 requires both IPv6 source and destination addresses to LOWPAN_HC1 requires both IPv6 source and destination addresses to
carry the prefix in-line. In cases where the Mesh Addressing header carry the prefix in-line. In cases where the Mesh Addressing header
is not used, the IID of a routable address must be carried in-line. is not used, the IID of a routable address must be carried in-line.
However, LOWPAN_HC1 requires 64-bits for the IID when carried in-line However, LOWPAN_HC1 requires 64-bits for the IID when carried in-line
skipping to change at page 4, line 16 skipping to change at page 4, line 16
LOWPAN_HC1 can be extended to include a LOWPAN_HC2 octet to support LOWPAN_HC1 can be extended to include a LOWPAN_HC2 octet to support
compression of UDP, TCP, or ICMPv6; that LOWPAN_HC2 octet is placed compression of UDP, TCP, or ICMPv6; that LOWPAN_HC2 octet is placed
right after the LOWPAN_HC1 octet and before the uncompressed IP right after the LOWPAN_HC1 octet and before the uncompressed IP
fields. This specification moves the transport control octet after fields. This specification moves the transport control octet after
the uncompressed IP fields for a more properly layered structure. the uncompressed IP fields for a more properly layered structure.
[RFC4944] defines a compression mechanism for UDP, but that mechanism [RFC4944] defines a compression mechanism for UDP, but that mechanism
does not enable checksum compression when rendered possible by does not enable checksum compression when rendered possible by
additional upper layer mechanisms such as upper layer Message additional upper layer mechanisms such as upper layer Message
Integrity Check (MIC). This specification adds the capability to Integrity Check (MIC). This specification adds the capability to
elide the UDP checksum over the LoWPAN, which allows savings of two compress the UDP checksum over the LoWPAN, which enables to save an
additional octets. additional pair of octets.
Finally, LOWPAN_HC1 lacks the flexibility to support the compression Finally, LOWPAN_HC1 lacks the flexibility to support the compression
of additional transport mechanisms that could be introduced in the of additional transport mechanisms that could be introduced in the
future. future.
This document specifies a header compression format for IPv6 This document specifies a header compression format for IPv6
datagrams. This format improves on the header compression format datagrams. This format improves on the header compression format
defined in [RFC4944] by generalizing it to support a broader range of defined in [RFC4944] by generalizing it to support a broader range of
communication paradigms, including both mesh-under and route-over communication paradigms, including both mesh-under and route-over
configurations; communication to nodes internal and external to the configurations; communication to nodes internal and external to the
6LoWPAN network; and multicast communication. This document also 6LoWPAN network; and multicast communication. This document also
defines a flexible framework for compressing arbitrary next headers defines a flexible framework for compressing arbitrary next headers
and defines UDP header compression within this framework. This and defines UDP header compression within this framework. This
compression format carries forward the design concepts in RFC 4944 compression format carries forward the design concepts in RFC 4944
[RFC4944], minimizing compression state and state maintenance by [RFC4944], minimizing any state and relying on shared context among
relying on shared context among all nodes in a 6LoWPAN network. all nodes in a 6LoWPAN network.
1.1. Requirements Language 1.1. 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].
2. IPv6 Header Compression 2. IPv6 Header Compression
In this section, we define the LOWPAN_IPHC encoding format for In this section, we define the LOWPAN_IPHC encoding format for
skipping to change at page 5, line 16 skipping to change at page 5, line 16
network; addresses assigned to 6LoWPAN interfaces are formed with an network; addresses assigned to 6LoWPAN interfaces are formed with an
IID derived directly from either the 64-bit extended or 16-bit short IID derived directly from either the 64-bit extended or 16-bit short
IEEE 802.15.4 addresses. IEEE 802.15.4 addresses.
+-------------------------------------+------------------------ +-------------------------------------+------------------------
| Dispatch + LOWPAN_IPHC (2-3 octets) | Compressed IPv6 Header | Dispatch + LOWPAN_IPHC (2-3 octets) | Compressed IPv6 Header
+-------------------------------------+------------------------ +-------------------------------------+------------------------
Figure 1: LOWPAN_IPHC Header Figure 1: LOWPAN_IPHC Header
The LOWPAN_IPHC encoding utilizes 13 bits, 5 of which are taken from The LOWPAN_IPHC encoding utilizes 11 bits, 3 of which are taken from
the rightmost bits of the dispatch type. The encoding may be the rightmost bit of the dispatch type. The encoding may be extended
extended by another octet to support additional contexts. by another octet to support additional contexts. Uncompressed IPv6
Uncompressed IPv6 header fields follow the LOWPAN_IPHC encoding, as header fields follow the LOWPAN_IPHC encoding, as shown in Figure 1.
shown in Figure 1. With the above scenario, the LOWPAN_IPHC can With the above scenario, the LOWPAN_IPHC can compress the IPv6 header
compress the IPv6 header down to two octets (the dispatch octet and down to two octets (the dispatch octet and the LOWPAN_IPHC encoding)
the LOWPAN_IPHC encoding) with link-local communication. When with link-local communication. When routing over multiple IP hops,
routing over multiple IP hops, LOWPAN_IPHC can compress the IPv6 LOWPAN_IPHC can compress the IPv6 header down to 7 octets (1-octet
header down to 7 octets (2-octets dispatch/LOWPAN_IPHC, 1-octet Hop dispatch, 1-octet LOWPAN_IPHC, 1-octet Hop Limit, 2-octet Source
Limit, 2-octet Source Address, and 2-octet Destination Address). Address, and 2-octet Destination Address).
2.1. LOWPAN_IPHC Encoding Format 2.1. LOWPAN_IPHC Encoding Format
2.1.1. Base Format 2.1.1. Base Format
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
| 0 | 1 | 1 | TF |NH | HLIM |CID|SAC| SAM | M |DAC| DAM | | 0 | 1 | 1 | TF |NH | HLIM |CID|SAC| SAM | M |DAC| DAM |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
Figure 2: LOWPAN_IPHC Encoding Figure 2: LOWPAN_IPHC Encoding
TF: Traffic Class, Flow Label: TF: Traffic Class, Flow Label:
00: Traffic Class + 4-bit Pad + Flow Label (4 bytes) 00: 4-bit Pad + Traffic Class + Flow Label (4 bytes)
01: ECN + 2-bit Pad + Flow Label (3 bytes) 01: ECN + 2-bit Pad + Flow Label (3 bytes)
10: Traffic Class (1 byte) 10: Traffic Class (1 byte)
11: Version, Traffic Class, and Flow Label are compressed. 11: Version, Traffic Class, and Flow Label are compressed.
NH: Next Header: NH: Next Header:
0: Full 8 bits for Next Header are carried in-line. 0: Full 8 bits for Next Header are carried in-line.
1: The Next Header field is compressed and the next header is 1: The Next Header field is compressed and the next header is
compressed using LOWPAN_NHC, which is discussed in Section 3. compressed using LOWPAN_NHC, which is discussed in Section 3.
HLIM: Hop Limit: HLIM: Hop Limit:
00: The Hop Limit field is carried in-line. 00: The Hop Limit field is carried in-line.
01: The Hop Limit field is elided and the the hop limit is 1. 01: The Hop Limit field is elided and the the hop limit is 1.
10: The Hop Limit field is elided and the the hop limit is 64. 10: The Hop Limit field is elided and the the hop limit is 64.
11: The Hop Limit field is elided and the hop limit is 255. 11: The Hop Limit field is elided and the hop limit is 255.
CID: Context Identifier Extension: CID: Context Identifier Extension:
0: No additional 8-bit Context Identifier Extension is used. If 0: No additional 8-bit Context Identifier Extension is used. If
context-based compression is specified in either SC or DC, the context-based compression is specified in either SC or DC,
default context is used. context 0 is used.
1: An additional 8-bit Context Identifier Extension field 1: An additional 8-bit Context Identifier Extension field
immediately follows the DAM field. immediately follows the DAM field.
SAC: Source Address Compression SAC: Source Address Compression
0: Source address compression uses stateless compression. 0: Source address compression uses stateless compression.
1: Source address compression uses stateful, context-based 1: Source address compression uses stateful, context-based
compression. compression.
SAM: Source Address Mode: SAM: Source Address Mode:
If SAC=0: If SAC=0:
00: 0 bits. The address is the unspecified address. 00: 128 bits. The full address is carried in-line.
01: 64 bits. The first 64-bits of the address are elided. 01: 64 bits. The first 64-bits of the address are elided.
The value of those bits is the link-local prefix padded with The value of those bits is the link-local prefix padded with
zeros. The remaining 64 bits are carried inline. zeros. The remaining 64 bits are carried inline.
10: 16 bits. The first 112 bits of the address are elided. 10: 16 bits. The first 112 bits of the address are elided.
The value of those bits is the link-local prefix padded with The value of those bits is the link-local prefix padded with
zeros. The remaining 16 bits are carried inline. zeros. The remaining 16 bits are carried inline.
11: 0 bits. The address is fully elided. The first 64 bits 11: 0 bits. The address is fully elided. The first 64 bits
of the address are elided. The remaining 64 bits are of the address are the link-local prefix padded with zeros.
computed from the link-layer address as defined in The remaining 64 bits are computed from the link-layer
[RFC4944]. address as defined in [RFC4944].
If SAC=1: If SAC=1:
00: 128 bits. The full address is carried in-line. 00: Reserved.
01: 64 bits. The first 64-bits of the address are elided. 01: 64 bits. The address is derived using context information
The value of those bits is taken from the context and padded and the 64 bits carried inline.
with zeros. The remaining 64 bits are carried inline. 10: 16 bits. The address is derived using context information
10: 16 bits. The first 112 bits of the address are elided. and the 16 bits carried inline.
The value of those bits is taken from the context and padded 11: 0 bits. The address is derived using context information
with zeros. The remaining 16 bits are carried inline. and possibly link-layer addresses.
11: 0 bits. The address is fully elided. The first 64 bits
are taken from the context. The remaining 64 bits are
computed from the link-layer address as defined in
[RFC4944].
M: Multicast Compression M: Multicast Compression
0: Destination address does not use multicast compression. 0: Destination address does not use multicast compression.
1: Destination address uses multicast compression. 1: Destination address uses multicast compression.
DAC: Destination Address Compression DAC: Destination Address Compression
0: Destination address compression uses stateless compression. 0: Destination address compression uses stateless compression.
1: Destination address compression uses stateful, context-based 1: Destination address compression uses stateful, context-based
compression. compression.
DAM: Destination Address Mode: DAM: Destination Address Mode:
If M=0: When DAC=0, any elided prefix bits are the link-local If M=0:
prefix padded by zeros. When DAC=1, any elided prefix bits are If DAC=0:
taken from the context and padded by zeros.
00: 128 bits. The full address is carried in-line. 00: 128 bits. The full address is carried in-line.
01: 64 bits. The first 64-bits of the address are elided. 01: 64 bits. The first 64-bits of the address are elided.
The remaining 64 bits are carried inline. The value of those bits is the link-local prefix padded
with zeros. The remaining 64 bits are carried inline.
10: 16 bits. The first 112 bits of the address are elided. 10: 16 bits. The first 112 bits of the address are elided.
The remaining 16 bits are carried inline. The value of those bits is the link-local prefix padded
11: 0 bits. The address is fully elided. The first 64 bits with zeros. The remaining 16 bits are carried inline.
of the address are elided. The remaining 64 bits are 11: 0 bits. The address is fully elided. The first 64
computed from the link-layer address as defined in bits of the address are the link-local prefix padded with
[RFC4944]. zeros. The remaining 64 bits are computed from the link-
layer address as defined in [RFC4944].
If DAC=1:
00: Reserved.
01: 64 bits. The address is derived using context
information and the 64 bits carried inline.
10: 16 bits. The address is derived using context
information and the 16 bits carried inline.
11: 0 bits. The address is derived using context
information and possibly link-layer addresses.
If M=1 and DAC=0: If M=1 and DAC=0:
00: 48 bits. The address takes the form FFXX::00XX:XXXX:XXXX. 00: 48 bits. The address takes the form FFXX::00XX:XXXX:XXXX.
01: 32 bits. The address takes the form FFXX::00XX:XXXX. 01: 32 bits. The address takes the form FFXX::00XX:XXXX.
10: 16 bits. The address takes the form FF0X::0XXX. 10: 16 bits. The address takes the form FF0X::0XXX.
11: 8 bits. The address takes the form FF02::00XX. 11: 8 bits. The address takes the form FF02::00XX.
If M=1 and DAC=1: If M=1 and DAC=1:
00: 128 bits. The full address is carried in-line. 00: 128 bits. The full address is carried in-line.
01: 48 bits. The address takes the form FFXX::XX[plen]: 01: 48 bits. The address takes the form FFXX::XXLL:PPPP:PPPP:
[prefix]:XXXX:XXXX. The values of plen and prefix are taken XXXX:XXXX. L denotes nibbles used to encode the prefix
from the specified context. length. P denotes nibbles used to encode the prefix itself.
The prefix information is taken from the specified context.
10: reserved 10: reserved
11: reserved 11: reserved
2.1.2. Context Identifier Extension 2.1.2. Context Identifier Extension
This specification expects that an abstract set of states called This specification expects that a concept of context is shared
contexts is shared between the node that compresses a packet and the between the node that compresses a packet and the node(s) that need
node(s) that need to expand it. The specification enables the to expand it. The specification enables a node to use of up to 16
transport of an opaque index that is used to lookup the abstract contexts. How the contexts are shared and maintained is out of
context database. The index in encoded with 4 bits enabling to scope. What the context information is is out of scope. Actions in
address up to 16 contexts. response to unknown and/or invalid contexts are out of scope.
This specification requires that services associated to the abstract
context database implement an interface to the 6LoWPAN compressor to
help compress and uncompress an address based on the parameters
passed by the compressor and the information in the abstract context
database.
The interface MUST provide the methods to lookup a context ID from a
prefix and a prefix length for encoding, and reversely lookup a
prefix and a prefix length from a context ID for decoding.
How the contexts are shared and maintained is out of scope. The
actual context information is out of scope. Actions in response to
unknown and/or invalid contexts are out of scope.
The interface might be extended to allow for further stateful
compression, for instance for SAC = 11, additional context
information might be used to store the full IPv6 address using the
Link layer Address as an additional index.
If the CID field is set to '1' in the LOWPAN_HC encoding, then an If the CIF field is set to '1' in the LOWPAN_IPHC encoding, then an
additional octet extends the LOWPAN_HC encoding following the DAM additional octet extends the LOWPAN_IPHC encoding following the DAM
bits but before the IPv6 header fields that are carried in-line. The bits but before the IPv6 header fields that are carried in-line. The
additional octet identifies the prefix when the IPv6 source and/or additional octet identifies the prefix when the IPv6 source and/or
destination address is compressed. The context identifier is 4 bits destination address is compressed. The context identifier is 4 bits
for each address, supporting up to 16 contexts. The encoding is for each address, supporting up to 16 contexts. The encoding is
shown in Figure 3. shown in Figure 3.
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| SCI | DCI | | SCI | DCI |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
skipping to change at page 8, line 48 skipping to change at page 8, line 39
SCI: Source Context Identifier Identifies the prefix that is used SCI: Source Context Identifier Identifies the prefix that is used
when the IPv6 source address is compressed. when the IPv6 source address is compressed.
DCI: Destination Context Identifier Identifies the prefix that is DCI: Destination Context Identifier Identifies the prefix that is
used when the IPv6 destination address is compressed. used when the IPv6 destination address is compressed.
2.2. IPv6 Header Encoding 2.2. IPv6 Header Encoding
Fields carried in-line (in part or in whole) appear in the same order Fields carried in-line (in part or in whole) appear in the same order
as they do in the IPv6 header format [RFC2460]. The Version field is as they do in the IPv6 header format [RFC2460]. The Version field is
always elided. The IPv6 Payload Length field MUST always be elided always elided. Unicast IPv6 addresses may be compressed to 64 or 16
and inferred from lower layers using the 6LoWPAN Fragmentation header bits or completely elided. Multicast IPv6 addresses may be
or the IEEE 802.15.4 header. Unicast IPv6 addresses may be compressed to 8, 16, or 24 bits. The IPv6 Payload Length field MUST
compressed to 64 or 16 bits or completely elided. Multicast IPv6 always be elided and inferred from lower layers using the 6LoWPAN
addresses may be compressed to 8, 16, or 24 bits. Fragmentation header or the IEEE 802.15.4 header.
2.2.1. Traffic Class and Flow Label Compression 2.2.1. Traffic Class and Flow Label Compression
The Traffic Class field in the IPv6 header comprises 6 bits of The Traffic Class field in the IPv6 header comprises 6 bits of
diffserv extension [RFC2474] and 2 bits of Explicit Congestion diffserv extension [RFC2474] and 2 bits of Explicit Congestion
Notification (ECN) [RFC3168]. If the ECN information is carried by Notification (ECN) [RFC3168]. If the ECN information is carried by
the Lower Layers in a compatible fashion then it can be elided from the Lower Layers in a compatible fashion then it can be elided from
the 6LoWPAN header. Otherwise, it has to be transported in one of the 6LoWPAN header. Otherwise, it has to be transported in one of
the following encodings. the following encodings.
The TF field in the LOWPAN_HC encoding indicate whether the Traffic The TF field in the LOWPAN_IPHC encoding indicate whether the Traffic
Class and Flow Label are carried in-line in the compressed IPv6 Class and Flow Label are carried in-line in the compressed IPv6
header. When Flow Label is included while the Traffic Class is header. When Flow Label is included while the Traffic Class is
compressed, an additional 4 bits are included to maintain byte- compressed, an additional 4 bits are included to maintain byte-
alignment. Two of the 4 bits contain the ECN bits from the Traffic alignment. Two of the 4 bits contain the ECN bits from the Traffic
Class field. Class field.
To ensure that the ECN bits appear in the same location for all To ensure that the ECN bits appear in the same location for all
encodings that include them, the Traffic Class field is rotated right encodings that include them, the Traffic Class field is rotated right
by 2 bits in the compressed IPv6 header. The encodings are shown by 2 bits in the compressed IPv6 header. The encodings are shown
below: below:
skipping to change at page 10, line 14 skipping to change at page 10, line 7
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|ECN| DSCP | |ECN| DSCP |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
TF = 10: Traffic Class carried in-line. TF = 10: Traffic Class carried in-line.
2.2.2. Stateless Multicast Addresses Compression 2.2.2. Stateless Multicast Addresses Compression
LOWPAN_HC supports stateless compression of multicast address when M LOWPAN_IPHC supports stateless compression of multicast address when
= 1 and SAC = 0. An IPv6 multicast address may be compressed down to M = 1 and SAC = 0. An IPv6 multicast address may be compressed down
48, 32, 16, or 8 bits using stateless compression. The format to 48, 32, 16, or 8 bits using stateless compression. The format
supports compression of the Solicited-Node Multicast Address (FF02:: supports compression of the Solicited-Node Multicast Address (FF02::
1:FFXX:XXXX) as well as any IPv6 multicast address where the upper 1:FFXX:XXXX) as well as any IPv6 multicast address where the upper
bits of the multicast group identifier are zero. The compressed bits of the multicast group identifier are zero. The compressed
forms only carry the least-significant bits of the multicast group forms only carry the least-significant bits of the multicast group
identifier. identifier. All compressed forms carry the multicast scope in-line
and all (except DAM=10) carry the multicast flags as well.
1 2 3 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Scope | Group Identifier | | Flags | Scope | Group Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Group Identifier | | Group Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
DAM = 00. 48-bit Compressed Multicast Address (FFfs::00gg:gggg:gggg) DAM = 00. 48-bit Compressed Multicast Address (FFfs::00gg:gggg:gggg)
skipping to change at page 11, line 17 skipping to change at page 11, line 14
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| Group ID | | Group ID |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
DAM = 11. 8-bit Compressed Multicast Address (FF02::gg). DAM = 11. 8-bit Compressed Multicast Address (FF02::gg).
2.2.3. Stateful Multicast Addresses Compression 2.2.3. Stateful Multicast Addresses Compression
LOWPAN_HC supports stateful compression of multicast addresses when M LOWPAN_IPHC supports stateful compression of multicast addresses when
= 1 and SAC = 1. This document currently defines SAM = 01: context- M = 1 and SAC = 1. This document currently defines SAM = 01:
based compression of Unicast-Prefix-based IPv6 Multicast Addresses context-based compression of Unicast-Prefix-based IPv6 Multicast
[RFC3306][RFC3956]. In particular, the Prefix Length and Network Addresses [RFC3306][RFC3956]. In particular, the Prefix Length and
Prefix can be taken from a context. As a result, LOWPAN_HC can Network Prefix can be taken from a context. As a result, LOWPAN_IPHC
compress a Unicast-Prefix-based IPv6 Multicast Address down to 6 can compress a Unicast-Prefix-based IPv6 Multicast Address down to 6
octets by only carrying the 4-bit Flags, 4-bit Scope, 8-bit RIID, and octets by only carrying the 4-bit Flags, 4-bit Scope, 8-bit RIID, and
32-bit Group Identifier in-line. 32-bit Group Identifier in-line.
1 2 3 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Scope | Reserved | Group Identifier | | Flags | Scope | Reserved | Group Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Group Identifier | | Group Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
DAM = 01. Unicast-Prefix-based IPv6 Multicast Address Compression DAM = 01. Unicast-Prefix-based IPv6 Multicast Address Compression
The Reserved field MUST carry the reserved bits from the multicast Note that the Reserved field MUST carry the reserved bits from the
address format as described in [RFC3306]. When a Rendezvous Point is multicast address format as described in [RFC3306]. When a
encoded in the multicast address as described in [RFC3956], the Rendezvous Point is encoded in the multicast address as described in
Reserved field carries the RIID bits in-line. [RFC3956], the Reserved field carries the RIID bits in-line.
3. IPv6 Next Header Compression 3. IPv6 Next Header Compression
LOWPAN_IPHC elides the IPv6 Next Header field when the NH bit is set LOWPAN_IPHC elides the IPv6 Next Header field when the NH bit is set
to 1. It also indicates the use of 6LoWPAN next header compression, to 1. It also indicates the use of 6LoWPAN next header compression,
LOWPAN_NHC. The value of IPv6 Next Header is recovered from the LOWPAN_NHC. The value of IPv6 Next Header is recovered from the
first bits in the LOWPAN_NHC encoding. The following bits are first bits in the LOWPAN_NHC encoding. The following bits are
specific to the IPv6 Next Header value. Figure 4 shows the structure specific to the IPv6 Next Header value. Figure 4 shows the structure
of an IPv6 datagram compressed using LOWPAN_IPHC and LOWPAN_NHC. of an IPv6 datagram compressed using LOWPAN_IPHC and LOWPAN_NHC.
skipping to change at page 12, line 34 skipping to change at page 12, line 29
remaining encoding bits SHOULD respect octet alignment. The remaining encoding bits SHOULD respect octet alignment. The
following bits are specific to the next header compression format. following bits are specific to the next header compression format.
In this document, we define a compression format for UDP headers. In this document, we define a compression format for UDP headers.
+----------------+--------------------------- +----------------+---------------------------
| var-len NHC ID | compressed next header... | var-len NHC ID | compressed next header...
+----------------+--------------------------- +----------------+---------------------------
Figure 5: LOWPAN_NHC Encoding Figure 5: LOWPAN_NHC Encoding
3.2. UDP Header Compression 3.2. IPv6 Extension Header Compression
A necessary property of encoding headers using LOWPAN_NHC is that the
immediately preceding header must either be encoded using LOWPAN_IPHC
or LOWPAN_NHC. In other words, all headers compressed using the
6LoWPAN header compression format defined in this document must be
contiguous. As a result, this document defines a set of LOWPAN_NHC
encodings for selected IPv6 Extension Headers such that the UDP
Header Compression defined in Section 3.3 may be used in the presence
of those extension headers.
The LOWPAN_NHC encodings for IPv6 Extension Headers are composed of a
single LOWPAN_NHC octet followed by the IPv6 Extension Header. The
format of the LOWPAN_NHC octet is shown in Figure 6. The first 7
bits serve as an identifier for the IPv6 Extension Header immediately
following the LOWPAN_NHC octet. The remaining bit indicates whether
or not the following header utilizes LOWPAN_NHC encoding.
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+
| 1 | 1 | 1 | 0 | EID |NH |
+---+---+---+---+---+---+---+---+
Figure 6: IPv6 Extension Header Encoding
EID: IPv6 Extension Header ID:
0: IPv6 Hop-by-Hop Options [RFC2460]
1: IPv6 Routing [RFC2460]
2: IPv6 Fragment [RFC2460]
3: IPv6 Destination Options [RFC2460]
4: IPv6 Mobility Header [RFC3775]
5: Reserved
6: Reserved
7: IPv6 Header
NH: Next Header:
0: Full 8 bits for Next Header are carried in-line.
1: The Next Header field is compressed and the next header is
compressed using LOWPAN_NHC, which is discussed in Section 3.
For the most part, the IPv6 Extension Header is carried verbatim in
the bytes immediately following the LOWPAN_NHC octet, with two
important exceptions: Length Field and Next Header Field.
The Next Header Field contained in IPv6 Extension Headers is elided
when the NH bit is set in the LOWPAN_NHC encoding octet. Note that
doing so allows LOWPAN_NHC to utilize no more overhead than the non-
encoded IPv6 Extension Header.
The Length Field contained in IPv6 Extension Headers indicate the
length of the IPv6 Extension Header in octets, not including the
LOWPAN_NHC byte. Note that this changes the standard Length Field
definition from indicating the header size in 8-octet units, not
including the first 8 octets. Changing the Length Field to be in
units of octets removes wasteful internal fragmentation. However,
specifying units in octets also means that LOWPAN_NHC CANNOT be used
to encode IPv6 Extension Headers that exceed 255 octets.
IPv6 Hop-by-Hop and Destination Options Headers may use Pad1 and PadN
to pad out the header to a multiple of 8 octets in length. When
using LOWPAN_NHC, those Pad1 and PadN options MAY be elided and the
length of the header reduced by the size of those Pad1 and PadN
options. When converting from the LOWPAN_NHC encoding back to the
standard IPv6 encoding, Pad1 and PadN options MUST be used to pad out
the containing header to a multiple of 8 octets in length if
necessary. Note that Pad1 and PadN options that do not appear at the
end of the containing header MUST NOT be elided as they are used to
align subsequent options.
When the identified next header is an IPv6 Header (EID=7), the NH bit
of the LOWPAN_NHC encoding is unused and SHOULD be set to zero. The
bytes following follow the LOWPAN_IPHC encoding as defined in
Section 2.
3.3. UDP Header Compression
This document defines a compression format for UDP headers using This document defines a compression format for UDP headers using
LOWPAN_NHC. The UDP compression format is shown in Figure 6. Bits 0 LOWPAN_NHC. The UDP compression format is shown in Figure 7. Bits 0
through 4 represent the NHC ID and '11110' indicates the specific UDP through 4 represent the NHC ID and '11110' indicates the specific UDP
header compression encoding defined in this section. header compression encoding defined in this section.
3.2.1. Compressing UDP ports 3.3.1. Compressing UDP ports
This specification introduces a range of well-known port (0xF0Bx) This specification introduces a range of well-known port (0xF0Bx)
that can be compressed to 4 bits. Considering that this represents that can be compressed to 4 bits. Considering that this represents
only 16 contiguous ports, it can be expected that many incompatible only 16 contiguous ports, it can be expected that many incompatible
applications will use the same port numbers of their own end-to-end applications will use the same port numbers of their own end-to-end
needs. needs.
The overloading of the 0xF0Bx ports increases the risk of getting the The overloading of the 0xF0Bx ports increases the risk of getting the
wrong type of payload and misinterpreting the content compared to wrong type of payload and misinterpreting the content compared to
ports that reserved at IANA. It is thus recommended that the use of ports that reserved at IANA. It is thus recommended that the use of
those ports be associated with a mechanism such as a Transport Layer those ports be associated with a mechanism such as a Transport Layer
Security (TLS) Message Integrity Check (MIC) that validates that the Security (TLS) Message Integrity Check (MIC) that validates that the
content is expected and checked for integrity. content is expected and checked for integrity.
3.2.2. Compressing UDP checksum 3.3.2. Compressing UDP checksum
The UDP checksum operation is mandatory with IPv6 [RFC2460] for all The UDP checksum operation is mandatory with IPv6 [RFC2460] for all
packets. For that reason [RFC4944] disallows the compression of the packets. For that reason [RFC4944] disallows the compression of the
UDP checksum. UDP checksum.
With this specification, a compressor in the source transport With this specification, a compressor in the source transport
endpoint MAY elide the UDP checksum in certain cases for instance: endpoint MAY elide the UDP checksum if it authorized by the Upper
Layer. The compressor SHOULD NOT set the C bit unless it has
received such authorization. The Upper Layer SHOULD only provide the
authorization in the following cases:
Upper Layer Message Integrity Check: In this case, there is some Tunneling: In this case, 6LowPAN is deployed as a wireless pseudo-
other form of integrity check in the UDP payload that covers at
least the same information as the UDP checksum (pseudo-header,
data) and has at least the same strength.
Tunneling: In this case, 6LoWPAN is deployed as a wireless pseudo-
fieldbus by tunneling existing field protocols over UDP. If the fieldbus by tunneling existing field protocols over UDP. If the
tunneled PDU possesses its own addressing, security and integrity tunneled PDU possesses its own addressing, security and integrity
check, the tunneling mechanism MAY authorize to elide the UDP check, the tunneling mechanism MAY authorize to elide the UDP
checksum in order to save on the encapsulation overhead. checksum in order to save on the encapsulation overhead.
This elision is indicated by setting the 'C' bit in the LOWPAN_NHC Upper Layer Message Integrity Check: In this case, there is some
header. other form of integrity check in the UDP payload that covers at
least the same information as the UDP checksum (pseudo-header,
data) and has at least the same strength.
A 6LoWPAN endpoint that compresses the LOWPAN_NHC header MUST NOT A forwarding node MAY imply authorization from the incoming packet
elide the UDP checksum (set the C bit) unless it has been authorized being forwarded if the C bit was set there. The forwarding node that
to do so by the source of the packet. In the source transport can not derive the authorization in an non-ambiguous fashion SHOULD
endpoint, this authorization can come from upper layer transport or NOT elide the UDP checksum when performing 6LoWPAN compression. The
application protocol instance that originated the packet. In a forwarding node that expands a 6LoWPAN packets with the C bit on MUST
forwarding node, this authorization is implied when the incoming compute the UDP checksum on behalf of the source node and place that
packet had the optimization applied (had the C bit set). checksum in the restored UDP header as specified in the incumbent
standards [RFC0768], [RFC2460].
A 6LoWPAN endpoint that expands the LOWPAN_NHC header MUST If a 6LoWPAN termination is also the transport endpoint, and it
reconstitute the UDP checksum by computing the valid value for the receives a compressed packet that has the C bit set, then it is
datagram as specified in [RFC0768] and [RFC2460], and place the entitled to ignore the UDP checksum process completely. If the C bit
result of that computation in the restored UDP header, unless it has is not set, the packet might have been forwarded by an edge router,
been authorized to ignore the checksum operation. In the destination so this is not an indication that the MIC is not present. If the
transport endpoint this authorization can come from upper layer terminating node knows that the message integrity will be validated
transport that will receive the packet and would ignore the UDP by the upper layer by some state associated to the Service Access
checksum should it be restored. Point, it is entitled to ignore the checksum operation as if the C
bit was set.
3.2.3. UDP LOWPAN_NHC Format 3.3.3. UDP LOWPAN_NHC Format
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| 1 | 1 | 1 | 1 | 0 | C | P | | 1 | 1 | 1 | 1 | 0 | C | P |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
Figure 6: UDP Header Encoding Figure 7: UDP Header Encoding
C: Checksum: C: Checksum:
0: All 16 bits of Checksum are carried in-line. 0: All 16 bits of Checksum are carried in-line.
1: All 16 bits of Checksum are elided. The Checksum is recovered 1: All 16 bits of Checksum are elided. The Checksum is recovered
by recomputing it on the 6LoWPAN termination point. by recomputing it on the 6LoWPAN termination point.
P: Ports: P: Ports:
00: All 16 bits for both Source Port and Destination Port are 00: All 16 bits for both Source Port and Destination Port are
carried in-line. carried in-line.
01: All 16 bits for Source Port are carried in-line. First 8 01: All 16 bits for Source Port are carried in-line. First 8
skipping to change at page 15, line 19 skipping to change at page 16, line 44
wrong type of payload and misinterpreting the content compared to wrong type of payload and misinterpreting the content compared to
ports that reserved at IANA. It is thus recommended that the use of ports that reserved at IANA. It is thus recommended that the use of
those ports be associated with a mechanism such as a Transport Layer those ports be associated with a mechanism such as a Transport Layer
Security (TLS) Message Integrity Check (MIC) that validates that the Security (TLS) Message Integrity Check (MIC) that validates that the
content is expected and checked for integrity. content is expected and checked for integrity.
6. Acknowledgements 6. Acknowledgements
Thanks to Julien Abeille, Carsten Bormann, Christos Polyzois, Erik Thanks to Julien Abeille, Carsten Bormann, Christos Polyzois, Erik
Nordmark, Robert Assimiti, Shoishi Sakane, Zach Shelby, Stephen Nordmark, Robert Assimiti, Shoishi Sakane, Zach Shelby, Stephen
Dawson-Haggerty, Jay Werb, and Mathilde Durvy for useful design Dawson-Haggerty, Jay Werb and Mathilde Durvy for useful design
consideration and implementation feedback. consideration and implementation feedback.
7. Changes 7. Changes
Draft 05:
- Added LOWPAN_NHC encodings for IPv6 Extension Headers.
- Specify use of context 0 when CID is 0.
- Indicate that first 64-bits is link-local prefix padded with
zeros when link-local prefix is elided.
- Made prefix-based multicast encoding format more explicit for
clarity.
- Changed wording around stateful compression to allow for using
the inline bits as an additional index to identify the compressed
address.
- Removed support for compressing unspecified address.
- Full 128-bit addr inline only in stateless encoding.
Draft 04: Draft 04:
- Fixed typos leftover from the changes in 03. - Fixed typos leftover from the changes in 03.
- Gave more details on UDP checksum compression. - Gave more details on UDP checksum compression.
- Greater discussion on the use of context information and - Clarify that the context information is out of scope.
clarification that its details are out of scope.
- Added security concern on 0xF0Bx port overloading. - Added security concern on 0xF0Bx port overloading.
Draft 03: Draft 03:
- Decoupled meaning of SAM bits from the destination address. - Decoupled meaning of SAM bits from the destination address.
- Have separate bit to indicate multicast address compression. - Have separate bit to indicate multicast address compression.
- More extensive support for multicast address compression, - More extensive support for multicast address compression,
including Unicast-Prefix-based Multicast Addresses. including Unicast-Prefix-based Multicast Addresses.
Draft 02: Draft 02:
- Updated wording with compression mode to clarify that a - Updated wording with compression mode to clarify that a
skipping to change at page 16, line 34 skipping to change at page 18, line 25
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS "Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474, Field) in the IPv4 and IPv6 Headers", RFC 2474,
December 1998. December 1998.
[RFC3168] Ramakrishnan, K., Floyd, S., and D. Black, "The Addition [RFC3168] Ramakrishnan, K., Floyd, S., and D. Black, "The Addition
of Explicit Congestion Notification (ECN) to IP", of Explicit Congestion Notification (ECN) to IP",
RFC 3168, September 2001. RFC 3168, September 2001.
[RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support
in IPv6", RFC 3775, June 2004.
[RFC4007] Deering, S., Haberman, B., Jinmei, T., Nordmark, E., and [RFC4007] Deering, S., Haberman, B., Jinmei, T., Nordmark, E., and
B. Zill, "IPv6 Scoped Address Architecture", RFC 4007, B. Zill, "IPv6 Scoped Address Architecture", RFC 4007,
March 2005. March 2005.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, February 2006. Architecture", RFC 4291, February 2006.
[RFC4302] Kent, S., "IP Authentication Header", RFC 4302,
December 2005.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, December 2005.
[RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler, [RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler,
"Transmission of IPv6 Packets over IEEE 802.15.4 "Transmission of IPv6 Packets over IEEE 802.15.4
Networks", RFC 4944, September 2007. Networks", RFC 4944, September 2007.
8.2. Informative References 8.2. Informative References
[IEEE 802.15.4] [IEEE 802.15.4]
IEEE Computer Society, "IEEE Std. 802.15.4-2006", IEEE Computer Society, "IEEE Std. 802.15.4-2006",
October 2006. October 2006.
skipping to change at page 18, line 4 skipping to change at line 823
Pascal Thubert Pascal Thubert
Cisco Systems Cisco Systems
Village d'Entreprises Green Side Village d'Entreprises Green Side
400, Avenue de Roumanille 400, Avenue de Roumanille
Batiment T3 Batiment T3
Biot - Sophia Antipolis 06410 Biot - Sophia Antipolis 06410
FRANCE FRANCE
Phone: +33 4 97 23 26 34 Phone: +33 4 97 23 26 34
Email: pthubert@cisco.com Email: pthubert@cisco.com
Full Copyright Statement
Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
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The IETF takes no position regarding the validity or scope of any
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this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
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The IETF invites any interested party to bring to its attention any
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