6Lo Working Group K. Lynn, Ed.
Internet-Draft Verizon Labs
Intended status: Standards Track J. Martocci
Expires: December 18, 2016 Johnson Controls
C. Neilson
Delta Controls
S. Donaldson
Honeywell
June 16, 2016
Transmission of IPv6 over MS/TP Networks
draft-ietf-6lo-6lobac-05
Abstract
Master-Slave/Token-Passing (MS/TP) is a medium access control method
for the RS-485 physical layer, which is used extensively in building
automation networks. This specification defines the frame format for
transmission of IPv6 packets and the method of forming link-local and
statelessly autoconfigured IPv6 addresses on MS/TP networks.
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 http://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 December 18, 2016.
Copyright Notice
Copyright (c) 2016 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
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
Lynn, et al. Expires December 18, 2016 [Page 1]
Internet-Draft IPv6 over MS/TP June 2016
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 . . . . . . . . . . . . . . . . . . . . . . . . 2
2. MS/TP Mode for IPv6 . . . . . . . . . . . . . . . . . . . . . 6
3. Addressing Modes . . . . . . . . . . . . . . . . . . . . . . 6
4. Maximum Transmission Unit (MTU) . . . . . . . . . . . . . . . 6
5. LoBAC Adaptation Layer . . . . . . . . . . . . . . . . . . . 7
6. Stateless Address Autoconfiguration . . . . . . . . . . . . . 8
7. IPv6 Link Local Address . . . . . . . . . . . . . . . . . . . 8
8. Unicast Address Mapping . . . . . . . . . . . . . . . . . . . 9
9. Multicast Address Mapping . . . . . . . . . . . . . . . . . . 9
10. Header Compression . . . . . . . . . . . . . . . . . . . . . 10
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
12. Security Considerations . . . . . . . . . . . . . . . . . . . 10
13. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
Appendix A. Abstract MAC Interface . . . . . . . . . . . . . . . 13
Appendix B. Consistent Overhead Byte Stuffing [COBS] . . . . . . 16
Appendix C. Encoded CRC-32K [CRC32K] . . . . . . . . . . . . . . 19
Appendix D. Example 6LoBAC Packet Decode . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26
1. Introduction
Master-Slave/Token-Passing (MS/TP) is a medium access control (MAC)
protocol for the RS-485 [TIA-485-A] physical layer, which is used
extensively in building automation networks. This specification
defines the frame format for transmission of IPv6 [RFC2460] packets
and the method of forming link-local and statelessly autoconfigured
IPv6 addresses on MS/TP networks. The general approach is to adapt
elements of the 6LoWPAN specifications [RFC4944], [RFC6282], and
[RFC6775] to constrained wired networks.
An MS/TP device is typically based on a low-cost microcontroller with
limited processing power and memory. Together with low data rates
and a small MAC address space, these constraints are similar to those
faced in 6LoWPAN networks and suggest some elements of that solution
might be leveraged. MS/TP differs significantly from 6LoWPAN in at
least three respects: a) MS/TP devices typically have a continuous
source of power, b) all MS/TP devices on a segment can communicate
directly so there are no hidden node or mesh routing issues, and c)
recent changes to MS/TP provide support for larger payloads,
Lynn, et al. Expires December 18, 2016 [Page 2]
Internet-Draft IPv6 over MS/TP June 2016
eliminating the need for fragmentation and reassembly below IPv6.
The following sections provide a brief overview of MS/TP, then
describe how to form IPv6 addresses and encapsulate IPv6 packets in
MS/TP frames. This document also specifies a header compression
mechanism, based on [RFC6282], that is REQUIRED in order to reduce
latency and make IPv6 practical on MS/TP networks.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
1.2. Abbreviations Used
ASHRAE: American Society of Heating, Refrigerating, and Air-
Conditioning Engineers (http://www.ashrae.org)
BACnet: An ISO/ANSI/ASHRAE Standard Data Communication Protocol
for Building Automation and Control Networks
CRC: Cyclic Redundancy Check
MAC: Medium Access Control
MSDU: MAC Service Data Unit (MAC client data)
MTU: Maximum Transmission Unit
UART: Universal Asynchronous Transmitter/Receiver
1.3. MS/TP Overview
This section provides a brief overview of MS/TP, which is specified
in ANSI/ASHRAE 135-2012 (BACnet) Clause 9 [Clause9] and included
herein by reference. BACnet [Clause9] also covers physical layer
deployment options.
MS/TP is designed to enable multidrop networks over shielded twisted
pair wiring. It can support network segments up to 1000 meters in
length at a data rate of 115,200 bit/s, or segments up to 1200 meters
in length at lower bit rates. An MS/TP link requires only a UART, an
RS-485 [TIA-485-A] transceiver with a driver that can be disabled,
and a 5 ms resolution timer. These features make MS/TP a cost-
effective field bus for the most numerous and least expensive devices
in a building automation network.
Lynn, et al. Expires December 18, 2016 [Page 3]
Internet-Draft IPv6 over MS/TP June 2016
The differential signaling used by [TIA-485-A] requires a contention-
free MAC. MS/TP uses a token to control access to a multidrop bus.
A master node may initiate the transmission of a data frame when it
holds the token. After sending at most a configured maximum number
of data frames, a master node passes the token to the next master
node (as determined by MAC address). If present on the link, legacy
MS/TP implementations (including all slave nodes) ignore the frame
format defined in this specification.
BACnet Addendum 135-2012an [Addendum_an] defines a range of Frame
Type values to designate frames that contain larger data and data CRC
fields, encoded using Consistent Overhead Byte Stuffing [COBS] (see
Appendix B). The purpose of COBS encoding is to eliminate preamble
sequences from the Encoded Data and Encoded CRC-32K fields. The
maximum length of an MSDU as defined by this specification is 1500
octets (before encoding). The Encoded Data is covered by a 32-bit
CRC [CRC32K] (see Appendix C). The CRC-32K is then COBS encoded.
MS/TP COBS-encoded frames have the following format:
0 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x55 | 0xFF | Frame Type | DA |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SA | Length (MS octet first) | Header CRC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. Encoded Data (2 - 1506 octets) .
. .
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | Encoded CRC-32K (5 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| | optional 0xFF |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: MS/TP COBS-Encoded Frame Format
MS/TP COBS-encoded frame fields have the following descriptions:
Lynn, et al. Expires December 18, 2016 [Page 4]
Internet-Draft IPv6 over MS/TP June 2016
Preamble two octet preamble: 0x55, 0xFF
Frame Type one octet
Destination Address one octet address
Source Address one octet address
Length two octets, most significant octet first
Header CRC one octet
Encoded Data 2 - 1506 octets (see Appendix B)
Encoded CRC-32K five octets (see Appendix C)
(pad) (optional) at most one octet of trailer: 0xFF
The Frame Type is used to distinguish between different types of MAC
frames. The types relevant to this specification (in decimal) are:
0 Token
1 Poll For Master
2 Reply To Poll For Master
...
34 IPv6 over MS/TP (LoBAC) Encapsulation
Frame Types 8 - 31 and 35 - 127 are reserved for assignment by
ASHRAE. Frame Types 32 - 127 designate COBS-encoded frames and MUST
convey Encoded Data and Encoded CRC-32K fields. All master nodes
MUST understand Token, Poll For Master, and Reply to Poll For Master
control frames. See Section 2 for additional details.
The Destination and Source Addresses are each one octet in length.
See Section 3 for additional details.
For COBS-encoded frames, the Length field indicates the size of the
[COBS] Encoded Data field in octets, plus three. (This adjustment is
required in order for legacy MS/TP devices to ignore COBS-encoded
frames.) See Section 4 and Appendices for additional details.
The Header CRC field covers the Frame Type, Destination Address,
Source Address, and Length fields. The Header CRC generation and
check procedures are specified in BACnet [Clause9].
1.4. Goals and Constraints
The primary goal of this specification is to enable IPv6 directly on
wired end devices in building automation and control networks by
leveraging existing standards to the greatest extent possible. A
secondary goal is to co-exist with legacy MS/TP implementations.
Only the minimum changes necessary to support IPv6 over MS/TP were
specified in BACnet [Addendum_an] (see Section 1.3).
In order to co-exist with legacy devices, no changes are permitted to
Lynn, et al. Expires December 18, 2016 [Page 5]
Internet-Draft IPv6 over MS/TP June 2016
the MS/TP addressing modes, frame header format, control frames, or
Master Node state machine as specified in BACnet [Clause9].
2. MS/TP Mode for IPv6
ASHRAE has assigned an MS/TP Frame Type value of 34 to indicate IPv6
over MS/TP (LoBAC) Encapsulation. This falls within the range of
values that designate COBS-encoded data frames.
All MS/TP master nodes (including those that support IPv6) must
implement the Master Node state machine specified in BACnet [Clause9]
and handle Token, Poll For Master, and Reply to Poll For Master
control frames. MS/TP master nodes that support IPv6 must also
implement the Receive Frame state machine specified in [Clause9] as
extended by BACnet [Addendum_an].
All MS/TP nodes that support IPv6 MUST support a data rate of 115,200
bit/s and MAY optionally support lower data rates as defined in
BACnet [Clause9].
3. Addressing Modes
MS/TP node (MAC) addresses are one octet in length. The method of
assigning MAC addresses is outside the scope of this specification.
However, each MS/TP node on the link MUST have a unique address in
order to ensure correct MAC operation.
BACnet [Clause9] specifies that addresses 0 through 127 are valid for
master nodes. The method specified in Section 6 for creating a MAC-
layer-derived Interface Identifier (IID) ensures that an IID of all
zeros can never result.
A Destination Address of 255 (all nodes) indicates a MAC-layer
broadcast. MS/TP does not support multicast, therefore all IPv6
multicast packets SHOULD be broadcast at the MAC layer and filtered
at the IPv6 layer. A Source Address of 255 MUST NOT be used.
Hosts learn IPv6 prefixes via router advertisements according to
[RFC4861].
4. Maximum Transmission Unit (MTU)
BACnet [Addendum_an] supports MSDUs up to 2032 octets in length.
This specification defines an MSDU length of at least 1280 octets and
at most 1500 octets (before encoding). This is sufficient to convey
the minimum MTU required by IPv6 [RFC2460] without the need for link-
layer fragmentation and reassembly. Support for an MSDU length of
1500 octets is RECOMMENDED.
Lynn, et al. Expires December 18, 2016 [Page 6]
Internet-Draft IPv6 over MS/TP June 2016
5. LoBAC Adaptation Layer
The relatively low data rates of MS/TP indicate header compression as
a means to reduce latency. This section specifies an adaptation
layer to support compressed IPv6 headers and the compression format
is specified in Section 10.
Implementations MAY also support Generic Header Compression (GHC)
[RFC7400] for transport layer headers. A node implementing [RFC7400]
MUST probe its peers for GHC support before applying GHC.
The encapsulation format defined in this section (subsequently
referred to as the "LoBAC" encapsulation) comprises the MSDU of an
IPv6 over MS/TP frame. The LoBAC payload (i.e., an IPv6 packet)
follows an encapsulation header stack. LoBAC is a subset of the
LoWPAN encapsulation defined in [RFC4944] and extended by [RFC6282],
therefore the use of "LOWPAN" in literals below is intentional. The
primary difference between LoWPAN and LoBAC is omission of the Mesh,
Broadcast, Fragmentation, and LOWPAN_HC1 headers.
All LoBAC encapsulated datagrams transmitted over MS/TP 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 LoBAC is the LOWPAN_IPHC header followed by payload, as
shown below:
+---------------+---------------+------...-----+
| IPHC Dispatch | IPHC Header | Payload |
+---------------+---------------+------...-----+
Figure 2: A LoBAC Encapsulated LOWPAN_IPHC Compressed IPv6 Datagram
The Dispatch value may be treated as an unstructured namespace. Only
a single pattern is used to represent current LoBAC functionality.
Pattern Header Type
+------------+-----------------------------------------------------+
| 01 1xxxxx | LOWPAN_IPHC - LOWPAN_IPHC compressed IPv6 [RFC6282] |
+------------+-----------------------------------------------------+
Figure 3: LoBAC Dispatch Value Bit Pattern
Other IANA-assigned 6LoWPAN Dispatch values do not apply to 6LoBAC
unless otherwise specified.
Lynn, et al. Expires December 18, 2016 [Page 7]
Internet-Draft IPv6 over MS/TP June 2016
6. Stateless Address Autoconfiguration
This section defines how to obtain an IPv6 Interface Identifier. The
general procedure for creating a MAC-address-derived IID is described
in [RFC4291] Appendix A, "Creating Modified EUI-64 Format Interface
Identifiers", as updated by [RFC7136].
The IID SHOULD NOT embed an [EUI-64] or any other globally unique
hardware identifier assigned to a device (see Section 12).
The Interface Identifier for link-local addresses SHOULD be formed by
concatenating a node's' 8-bit MS/TP MAC address to the seven octets
0x00, 0x00, 0x00, 0xFF, 0xFE, 0x00, 0x00. For example, an MS/TP MAC
address of hexadecimal value 0x4F results in the following IID:
|0 1|1 3|3 4|4 6|
|0 5|6 1|2 7|8 3|
+----------------+----------------+----------------+----------------+
|0000000000000000|0000000011111111|1111111000000000|0000000001001111|
+----------------+----------------+----------------+----------------+
This is the RECOMMENDED method of forming an IID for use in link-
local addresses, as it affords the most efficient header compression
provided by the LOWPAN_IPHC [RFC6282] format specified in Section 10.
A 64-bit privacy IID is RECOMMENDED for each forwardable address and
SHOULD be locally generated according to one of the methods cited in
Section 12. A node that generates a 64-bit privacy IID MUST register
it with its local router(s) by sending a Neighbor Solicitation (NS)
message with the Address Registration Option (ARO) and process
Neighbor Advertisements (NA) according to [RFC6775].
An IPv6 address prefix used for stateless autoconfiguration [RFC4862]
of an MS/TP interface MUST have a length of 64 bits.
7. IPv6 Link Local Address
The IPv6 link-local address [RFC4291] for an MS/TP interface is
formed by appending the Interface Identifier, as defined above, to
the prefix FE80::/64.
10 bits 54 bits 64 bits
+----------+-----------------------+----------------------------+
|1111111010| (zeros) | Interface Identifier |
+----------+-----------------------+----------------------------+
Lynn, et al. Expires December 18, 2016 [Page 8]
Internet-Draft IPv6 over MS/TP June 2016
8. Unicast Address Mapping
The address resolution procedure for mapping IPv6 non-multicast
addresses into MS/TP MAC-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 8-bit MS/TP MAC-layer (node) addresses.
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length=1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x00 | MS/TP Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Padding (all zeros) +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Option fields:
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 8-bit MS/TP MAC addresses.
MS/TP Address: The 8-bit address in canonical bit order [RFC2469].
This is the unicast address the interface currently responds to.
9. Multicast Address Mapping
All IPv6 multicast packets SHOULD be sent to MS/TP Destination
Address 255 (broadcast) and filtered at the IPv6 layer. When
represented as a 16-bit address in a compressed header (see
Section 10), it MUST be formed by padding on the left with a zero:
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x00 | 0xFF |
+-+-+-+-+-+-+-+-+---------------+
Lynn, et al. Expires December 18, 2016 [Page 9]
Internet-Draft IPv6 over MS/TP June 2016
10. Header Compression
LoBAC uses LOWPAN_IPHC IPv6 compression, which is specified in
[RFC6282] and included herein by reference. This section will simply
identify substitutions that should be made when interpreting the text
of [RFC6282].
In general the following substitutions should be made:
- Replace instances of "6LoWPAN" with "MS/TP network"
- Replace instances of "IEEE 802.15.4 address" with "MS/TP address"
When a 16-bit address is called for (i.e., an IEEE 802.15.4 "short
address") it MUST be formed by padding the MS/TP address to the left
with a zero:
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x00 | MS/TP address |
+-+-+-+-+-+-+-+-+---------------+
If LOWPAN_IPHC compression [RFC6282] is used with context, the
router(s) directly attached to the MS/TP segment MUST disseminate the
6LoWPAN Context Option (6CO) according to [RFC6775], Section 7.2.
11. IANA Considerations
This document uses values previously reserved by [RFC4944] and
[RFC6282] and makes no further requests of IANA.
Note to RFC Editor: this section may be removed upon publication.
12. Security Considerations
Forwardable addresses that contain IIDs generated using MS/TP node
addresses may expose a network to address scanning attacks. For this
reason, it is RECOMMENDED that a different (but stable) IID be
generated for each forwardable address in use according to, for
example, [RFC3315], [RFC3972], [RFC4941], [RFC5535], or [RFC7217].
MS/TP networks are by definition wired and not susceptible to casual
eavesdropping. By the same token, MS/TP nodes are stationary and
correlation of activities or location tracking of individuals is
unlikely.
Lynn, et al. Expires December 18, 2016 [Page 10]
Internet-Draft IPv6 over MS/TP June 2016
13. Acknowledgments
We are grateful to the authors of [RFC4944] and members of the IETF
6LoWPAN working group; this document borrows liberally from their
work. Ralph Droms and Brian Haberman provided indispensable guidance
and support from the outset. Peter van der Stok, James Woodyatt, and
Carsten Bormann provided detailed reviews. Stuart Cheshire invented
the very clever COBS encoding. Michael Osborne made the critical
observation that separately encoding the data and CRC32K fields would
allow the CRC to be calculated on-the-fly. Alexandru Petrescu, Brian
Frank, Geoff Mulligan, and Don Sturek offered valuable comments.
14. References
14.1. Normative References
[Addendum_an]
ASHRAE, "ANSI/ASHRAE Addenda an, at, au, av, aw, ax, and
az to ANSI/ASHRAE Standard 135-2012, BACnet - A Data
Communication Protocol for Building Automation and Control
Networks", July 2014,
<https://www.ashrae.org/File%20Library/docLib/StdsAddenda/
07-31-2014_135_2012_an_at_au_av_aw_ax_az_Final.pdf>.
[Clause9] American Society of Heating, Refrigerating, and Air-
Conditioning Engineers, "BACnet - A Data Communication
Protocol for Building Automation and Control Networks",
ANSI/ASHRAE 135-2012 (Clause 9), March 2013.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460,
December 1998, <http://www.rfc-editor.org/info/rfc2460>.
[RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins,
C., and M. Carney, "Dynamic Host Configuration Protocol
for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July
2003, <http://www.rfc-editor.org/info/rfc3315>.
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
RFC 3972, DOI 10.17487/RFC3972, March 2005,
<http://www.rfc-editor.org/info/rfc3972>.
Lynn, et al. Expires December 18, 2016 [Page 11]
Internet-Draft IPv6 over MS/TP June 2016
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, DOI 10.17487/RFC4291, February
2006, <http://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,
<http://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,
<http://www.rfc-editor.org/info/rfc4862>.
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
Extensions for Stateless Address Autoconfiguration in
IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007,
<http://www.rfc-editor.org/info/rfc4941>.
[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,
<http://www.rfc-editor.org/info/rfc4944>.
[RFC5535] Bagnulo, M., "Hash-Based Addresses (HBA)", RFC 5535,
DOI 10.17487/RFC5535, June 2009,
<http://www.rfc-editor.org/info/rfc5535>.
[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,
<http://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,
<http://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, <http://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,
<http://www.rfc-editor.org/info/rfc7217>.
Lynn, et al. Expires December 18, 2016 [Page 12]
Internet-Draft IPv6 over MS/TP June 2016
[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, <http://www.rfc-editor.org/info/rfc7400>.
14.2. Informative References
[COBS] Cheshire, S. and M. Baker, "Consistent Overhead Byte
Stuffing", IEEE/ACM TRANSACTIONS ON NETWORKING, VOL.7,
NO.2 , April 1999,
<http://www.stuartcheshire.org/papers/COBSforToN.pdf>.
[CRC32K] Koopman, P., "32-Bit Cyclic Redundancy Codes for Internet
Applications", IEEE/IFIP International Conference on
Dependable Systems and Networks (DSN 2002) , June 2002,
<http://www.ece.cmu.edu/~koopman/networks/dsn02/
dsn02_koopman.pdf>.
[EUI-64] IEEE, "Guidelines for 64-bit Global Identifier (EUI-64)
Registration Authority", March 1997,
<http://standards.ieee.org/regauth/oui/tutorials/
EUI64.html>.
[IEEE.802.3]
"Information technology - Telecommunications and
information exchange between systems - Local and
metropolitan area networks - Specific requirements - Part
3: Carrier Sense Multiple Access with Collision Detection
(CMSA/CD) Access Method and Physical Layer
Specifications", IEEE Std 802.3-2012, December 2012,
<http://standards.ieee.org/getieee802/802.3.html>.
[RFC2469] Narten, T. and C. Burton, "A Caution On The Canonical
Ordering Of Link-Layer Addresses", RFC 2469,
DOI 10.17487/RFC2469, December 1998,
<http://www.rfc-editor.org/info/rfc2469>.
[TIA-485-A]
Telecommunications Industry Association, "TIA-485-A,
Electrical Characteristics of Generators and Receivers for
Use in Balanced Digital Multipoint Systems (ANSI/TIA/EIA-
485-A-98) (R2003)", March 2003.
Appendix A. Abstract MAC Interface
This Appendix is informative and not part of the standard.
BACnet [Clause9] provides support for MAC-layer clients through its
Lynn, et al. Expires December 18, 2016 [Page 13]
Internet-Draft IPv6 over MS/TP June 2016
SendFrame and ReceivedDataNoReply procedures. However, it does not
define a network-protocol independent abstract interface for the MAC.
This is provided below as an aid to implementation.
A.1. MA-DATA.request
A.1.1. Function
This primitive defines the transfer of data from a MAC client entity
to a single peer entity or multiple peer entities in the case of a
broadcast address.
A.1.2. Semantics of the Service Primitive
The semantics of the primitive are as follows:
MA-DATA.request (
destination_address,
source_address,
data,
type
)
The 'destination_address' parameter may specify either an individual
or a broadcast MAC entity address. It must contain sufficient
information to create the Destination Address field (see Section 1.3)
that is prepended to the frame by the local MAC sublayer entity. The
'source_address' parameter, if present, must specify an individual
MAC address. If the source_address parameter is omitted, the local
MAC sublayer entity will insert a value associated with that entity.
The 'data' parameter specifies the MAC service data unit (MSDU) to be
transferred by the MAC sublayer entity. There is sufficient
information associated with the MSDU for the MAC sublayer entity to
determine the length of the data unit.
The 'type' parameter specifies the value of the MS/TP Frame Type
field that is prepended to the frame by the local MAC sublayer
entity.
A.1.3. When Generated
This primitive is generated by the MAC client entity whenever data
shall be transferred to a peer entity or entities. This can be in
response to a request from higher protocol layers or from data
generated internally to the MAC client, such as a Token frame.
Lynn, et al. Expires December 18, 2016 [Page 14]
Internet-Draft IPv6 over MS/TP June 2016
A.1.4. Effect on Receipt
Receipt of this primitive will cause the MAC entity to insert all MAC
specific fields, including Destination Address, Source Address, Frame
Type, and any fields that are unique to the particular media access
method, and pass the properly formed frame to the lower protocol
layers for transfer to the peer MAC sublayer entity or entities.
A.2. MA-DATA.indication
A.2.1. Function
This primitive defines the transfer of data from the MAC sublayer
entity to the MAC client entity or entities in the case of a
broadcast address.
A.2.2. Semantics of the Service Primitive
The semantics of the primitive are as follows:
MA-DATA.indication (
destination_address,
source_address,
data,
type
)
The 'destination_address' parameter may be either an individual or a
broadcast address as specified by the Destination Address field of
the incoming frame. The 'source_address' parameter is an individual
address as specified by the Source Address field of the incoming
frame.
The 'data' parameter specifies the MAC service data unit (MSDU) as
received by the local MAC entity. There is sufficient information
associated with the MSDU for the MAC sublayer client to determine the
length of the data unit.
The 'type' parameter is the value of the MS/TP Frame Type field of
the incoming frame.
A.2.3. When Generated
The MA_DATA.indication is passed from the MAC sublayer entity to the
MAC client entity or entities to indicate the arrival of a frame to
the local MAC sublayer entity that is destined for the MAC client.
Such frames are reported only if they are validly formed, received
without error, and their destination address designates the local MAC
Lynn, et al. Expires December 18, 2016 [Page 15]
Internet-Draft IPv6 over MS/TP June 2016
entity. Frames destined for the MAC Control sublayer are not passed
to the MAC client.
A.2.4. Effect on Receipt
The effect of receipt of this primitive by the MAC client is
unspecified.
Appendix B. Consistent Overhead Byte Stuffing [COBS]
This Appendix is informative and not part of the standard.
BACnet [Addendum_an] corrects a long-standing issue with the MS/TP
specification; namely that preamble sequences were not escaped
whenever they appeared in the Data or Data CRC fields. In rare
cases, this resulted in dropped frames due to loss of frame
synchronization. The solution is to encode the Data and 32-bit Data
CRC fields before transmission using Consistent Overhead Byte
Stuffing [COBS] and decode these fields upon reception.
COBS is a run-length encoding method that nominally removes '0x00'
octets from its input. Any selected octet value may be removed by
XOR'ing that value with each octet of the COBS output. BACnet
[Addendum_an] specifies the preamble octet '0x55' for removal.
The minimum overhead of COBS is one octet per encoded field. The
worst-case overhead in long fields is bounded to one octet per 254,
or less than 0.4%, as described in [COBS].
Frame encoding proceeds logically in two passes. The Encoded Data
field is prepared by passing the MSDU through the COBS encoder and
XOR'ing the preamble octet '0x55' with each octet of the output. The
Encoded CRC-32K field is then prepared by calculating a CRC-32K over
the Encoded Data field and formatting it for transmission as
described in Appendix C. The combined length of these fields, minus
two octets for compatibility with existing MS/TP devices, is placed
in the MS/TP header Length field before transmission.
Example COBS encoder and decoder functions are shown below for
illustration. Complete examples of use and test vectors are provided
in BACnet [Addendum_an].
#include <stddef.h>
#include <stdint.h>
/*
* Encodes 'length' octets of data located at 'from' and
* writes one or more COBS code blocks at 'to', removing any
Lynn, et al. Expires December 18, 2016 [Page 16]
Internet-Draft IPv6 over MS/TP June 2016
* 'mask' octets that may present be in the encoded data.
* Returns the length of the encoded data.
*/
size_t
cobs_encode (uint8_t *to, const uint8_t *from, size_t length,
uint8_t mask)
{
size_t code_index = 0;
size_t read_index = 0;
size_t write_index = 1;
uint8_t code = 1;
uint8_t data, last_code;
while (read_index < length) {
data = from[read_index++];
/*
* In the case of encountering a non-zero octet in the data,
* simply copy input to output and increment the code octet.
*/
if (data != 0) {
to[write_index++] = data ^ mask;
code++;
if (code != 255)
continue;
}
/*
* In the case of encountering a zero in the data or having
* copied the maximum number (254) of non-zero octets, store
* the code octet and reset the encoder state variables.
*/
last_code = code;
to[code_index] = code ^ mask;
code_index = write_index++;
code = 1;
}
/*
* If the last chunk contains exactly 254 non-zero octets, then
* this exception is handled above (and returned length must be
* adjusted). Otherwise, encode the last chunk normally, as if
* a "phantom zero" is appended to the data.
*/
if ((last_code == 255) && (code == 1))
write_index--;
else
to[code_index] = code ^ mask;
return write_index;
Lynn, et al. Expires December 18, 2016 [Page 17]
Internet-Draft IPv6 over MS/TP June 2016
}
#include <stddef.h>
#include <stdint.h>
/*
* Decodes 'length' octets of data located at 'from' and
* writes the original client data at 'to', restoring any
* 'mask' octets that may present in the encoded data.
* Returns the length of the encoded data or zero if error.
*/
size_t
cobs_decode (uint8_t *to, const uint8_t *from, size_t length,
uint8_t mask)
{
size_t read_index = 0;
size_t write_index = 0;
uint8_t code, last_code;
while (read_index < length) {
code = from[read_index] ^ mask;
last_code = code;
/*
* Sanity check the encoding to prevent the while() loop below
* from overrunning the output buffer.
*/
if (read_index + code > length)
return 0;
read_index++;
while (--code > 0)
to[write_index++] = from[read_index++] ^ mask;
/*
* Restore the implicit zero at the end of each decoded block
* except when it contains exactly 254 non-zero octets or the
* end of data has been reached.
*/
if ((last_code != 255) && (read_index < length))
to[write_index++] = 0;
}
return write_index;
}
Lynn, et al. Expires December 18, 2016 [Page 18]
Internet-Draft IPv6 over MS/TP June 2016
Appendix C. Encoded CRC-32K [CRC32K]
This Appendix is informative and not part of the standard.
Extending the payload of MS/TP to 1500 octets required upgrading the
Data CRC from 16 bits to 32 bits. P.Koopman has authored several
papers on evaluating CRC polynomials for network applications. In
[CRC32K], he surveyed the entire 32-bit polynomial space and noted
some that exceed the [IEEE.802.3] polynomial in performance. BACnet
[Addendum_an] specifies the CRC-32K (Koopman) polynomial.
The specified use of the calc_crc32K() function is as follows.
Before a frame is transmitted, 'crc_value' is initialized to all
ones. After passing each octet of the [COBS] Encoded Data through
the function, the ones complement of the resulting 'crc_value' is
arranged in LSB-first order and is itself [COBS] encoded. The length
of the resulting Encoded CRC-32K field is always five octets.
Upon reception of a frame, 'crc_value' is initialized to all ones.
The octets of the Encoded Data field are accumulated by the
calc_crc32K() function before decoding. The Encoded CRC-32K field is
then decoded and the resulting four octets are accumulated by the
calc_crc32K() function. If the result is the expected residue value
'CRC32K_RESIDUE', then the frame was received correctly.
An example CRC-32K function in shown below for illustration.
Complete examples of use and test vectors are provided in BACnet
[Addendum_an].
Lynn, et al. Expires December 18, 2016 [Page 19]
Internet-Draft IPv6 over MS/TP June 2016
#include <stdint.h>
/* See BACnet Addendum 135-2012an, section G.3.2 */
#define CRC32K_INITIAL_VALUE (0xFFFFFFFF)
#define CRC32K_RESIDUE (0x0843323B)
/* CRC-32K polynomial, 1 + x**1 + ... + x**30 (+ x**32) */
#define CRC32K_POLY (0xEB31D82E)
/*
* Accumulate 'data_value' into the CRC in 'crc_value'.
* Return updated CRC.
*
* Note: crc_value must be set to CRC32K_INITIAL_VALUE
* before initial call.
*/
uint32_t
calc_crc32K (uint8_t data_value, uint32_t crc_value)
{
int b;
for (b = 0; b < 8; b++) {
if ((data_value & 1) ^ (crc_value & 1)) {
crc_value >>= 1;
crc_value ^= CRC32K_POLY;
} else {
crc_value >>= 1;
}
data_value >>= 1;
}
return crc_value;
}
Lynn, et al. Expires December 18, 2016 [Page 20]
Internet-Draft IPv6 over MS/TP June 2016
Appendix D. Example 6LoBAC Packet Decode
This Appendix is informative and not part of the standard.
BACnet MS/TP, Src (2), Dst (1), IPv6 Encapsulation
Preamble 55: 0x55
Preamble FF: 0xff
Frame Type: IPv6 Encapsulation (34)
Destination Address: 1
Source Address: 2
Length: 537
Header CRC: 0x1c [correct]
Extended Data CRC: 0x9e7259e2 [correct]
6LoWPAN
IPHC Header
011. .... = Pattern: IP header compression (0x03)
...1 1... .... .... = Traffic class and flow label:
Version, traffic class, and flow label
compressed (0x0003)
.... .0.. .... .... = Next header: Inline
.... ..00 .... .... = Hop limit: Inline (0x0000)
.... .... 1... .... = Context identifier extension: True
.... .... .1.. .... = Source address compression: Stateful
.... .... ..01 .... = Source address mode:
64-bits inline (0x0001)
.... .... .... 0... = Multicast address compression: False
.... .... .... .1.. = Destination address compression:
Stateful
.... .... .... ..10 = Destination address mode:
16-bits inline (0x0002)
0000 .... = Source context identifier: 0x00
.... 0000 = Destination context identifier: 0x00
[Source context: aaaa:: (aaaa::)]
[Destination context: aaaa:: (aaaa::)]
Next header: ICMPv6 (0x3a)
Hop limit: 63
Source: aaaa::1 (aaaa::1)
Destination: aaaa::ff:fe00:1 (aaaa::ff:fe00:1)
Internet Protocol Version 6, Src: aaaa::1 (aaaa::1),
Dst: aaaa::ff:fe00:1 (aaaa::ff:fe00:1)
0110 .... .... .... .... .... .... .... = Version: 6
.... 0000 0000 .... .... .... .... .... = Traffic class:
0x00000000
.... 0000 00.. .... .... .... .... .... = Differentiated
Services Field:
Default (0x00000000)
.... .... ..0. .... .... .... .... .... = ECN-Capable Transport
Lynn, et al. Expires December 18, 2016 [Page 21]
Internet-Draft IPv6 over MS/TP June 2016
(ECT): Not set
.... .... ...0 .... .... .... .... .... = ECN-CE: Not set
.... .... .... 0000 0000 0000 0000 0000 = Flowlabel: 0x00000000
Payload length: 518
Next header: ICMPv6 (58)
Hop limit: 63
Source: aaaa::1 (aaaa::1)
Destination: aaaa::ff:fe00:1 (aaaa::ff:fe00:1)
Internet Control Message Protocol v6
Type: Echo (ping) request (128)
Code: 0
Checksum: 0x783f [correct]
Identifier: 0x2ee5
Sequence: 2
[Response In: 5165]
Data (510 bytes)
Data: e4dbe8553ba0040008090a0b0c0d0e0f1011121314151617...
[Length: 510]
Lynn, et al. Expires December 18, 2016 [Page 22]
Internet-Draft IPv6 over MS/TP June 2016
Frame (547 bytes):
55 ff 22 01 02 02 19 1c 56 2d 83 56 6f 6a 54 54 U.".....V-.VojTT
54 54 54 54 57 54 56 54 d5 50 2d 6a 7b b0 5c 57 TTTTWTVT.P-j{.\W
b1 8e bd 00 6e f5 51 ac 5d 5c 5f 5e 59 58 5b 5a ....n.Q.]\_^YX[Z
45 44 47 46 41 40 43 42 4d 4c 4f 4e 49 48 4b 4a EDGFA@CBMLONIHKJ
75 74 77 76 71 70 73 72 7d 7c 7f 7e 79 78 7b 7a utwvqpsr}|.~yx{z
65 64 67 66 61 60 63 62 6d 6c 6f 6e 69 68 6b 6a edgfa`cbmlonihkj
15 14 17 16 11 10 13 12 1d 1c 1f 1e 19 18 1b 1a ................
05 04 07 06 01 00 03 02 0d 0c 0f 0e 09 08 0b 0a ................
35 34 37 36 31 30 33 32 3d 3c 3f 3e 39 38 3b 3a 54761032=<?>98;:
25 24 27 26 21 20 23 22 2d 2c 2f 2e 29 28 2b 2a %$'&! #"-,/.)(+*
d5 d4 d7 d6 d1 d0 d3 d2 dd dc df de d9 d8 db da ................
c5 c4 c7 c6 c1 c0 c3 c2 cd cc cf ce c9 c8 cb ca ................
f5 f4 f7 f6 f1 f0 f3 f2 fd fc ff fe f9 f8 fb fa ................
e5 e4 e7 e6 e1 e0 e3 e2 ed ec ef ee e9 e8 eb ea ................
95 94 97 96 91 90 93 92 9d 9c 9f 9e 99 98 9b 9a ................
85 84 87 86 81 80 83 82 8d 8c 8f 8e 89 88 8b 8a ................
b5 b4 b7 b6 b1 b0 b3 b2 bd bc bf be b9 b8 bb ba ................
a5 a4 a7 a6 a1 a0 a3 a2 ad ac af ae a9 a8 ab aa ................
ab 54 57 56 51 50 53 52 5d 5c 5f 5e 59 58 5b 5a .TWVQPSR]\_^YX[Z
45 44 47 46 41 40 43 42 4d 4c 4f 4e 49 48 4b 4a EDGFA@CBMLONIHKJ
75 74 77 76 71 70 73 72 7d 7c 7f 7e 79 78 7b 7a utwvqpsr}|.~yx{z
65 64 67 66 61 60 63 62 6d 6c 6f 6e 69 68 6b 6a edgfa`cbmlonihkj
15 14 17 16 11 10 13 12 1d 1c 1f 1e 19 18 1b 1a ................
05 04 07 06 01 00 03 02 0d 0c 0f 0e 09 08 0b 0a ................
35 34 37 36 31 30 33 32 3d 3c 3f 3e 39 38 3b 3a 54761032=<?>98;:
25 24 27 26 21 20 23 22 2d 2c 2f 2e 29 28 2b 2a %$'&! #"-,/.)(+*
d5 d4 d7 d6 d1 d0 d3 d2 dd dc df de d9 d8 db da ................
c5 c4 c7 c6 c1 c0 c3 c2 cd cc cf ce c9 c8 cb ca ................
f5 f4 f7 f6 f1 f0 f3 f2 fd fc ff fe f9 f8 fb fa ................
e5 e4 e7 e6 e1 e0 e3 e2 ed ec ef ee e9 e8 eb ea ................
95 94 97 96 91 90 93 92 9d 9c 9f 9e 99 98 9b 9a ................
85 84 87 86 81 80 83 82 8d 8c 8f 8e 89 88 8b 8a ................
b5 b4 b7 b6 b1 b0 b3 b2 bd bc bf be b9 b8 bb ba ................
a5 a4 a7 a6 a1 a0 a3 a2 ad ac af ae a9 a8 50 cb ..............P.
27 0c b7 '..
Lynn, et al. Expires December 18, 2016 [Page 23]
Internet-Draft IPv6 over MS/TP June 2016
Decoded Data and CRC32K (537 bytes):
78 d6 00 3a 3f 00 00 00 00 00 00 00 01 00 01 80 x..:?...........
00 78 3f 2e e5 00 02 e4 db e8 55 3b a0 04 00 08 .x?.......U;....
09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 18 ................
19 1a 1b 1c 1d 1e 1f 20 21 22 23 24 25 26 27 28 ....... !"#$%&'(
29 2a 2b 2c 2d 2e 2f 30 31 32 33 34 35 36 37 38 )*+,-./012345678
39 3a 3b 3c 3d 3e 3f 40 41 42 43 44 45 46 47 48 9:;<=>?@ABCDEFGH
49 4a 4b 4c 4d 4e 4f 50 51 52 53 54 55 56 57 58 IJKLMNOPQRSTUVWX
59 5a 5b 5c 5d 5e 5f 60 61 62 63 64 65 66 67 68 YZ[\]^_`abcdefgh
69 6a 6b 6c 6d 6e 6f 70 71 72 73 74 75 76 77 78 ijklmnopqrstuvwx
79 7a 7b 7c 7d 7e 7f 80 81 82 83 84 85 86 87 88 yz{|}~..........
89 8a 8b 8c 8d 8e 8f 90 91 92 93 94 95 96 97 98 ................
99 9a 9b 9c 9d 9e 9f a0 a1 a2 a3 a4 a5 a6 a7 a8 ................
a9 aa ab ac ad ae af b0 b1 b2 b3 b4 b5 b6 b7 b8 ................
b9 ba bb bc bd be bf c0 c1 c2 c3 c4 c5 c6 c7 c8 ................
c9 ca cb cc cd ce cf d0 d1 d2 d3 d4 d5 d6 d7 d8 ................
d9 da db dc dd de df e0 e1 e2 e3 e4 e5 e6 e7 e8 ................
e9 ea eb ec ed ee ef f0 f1 f2 f3 f4 f5 f6 f7 f8 ................
f9 fa fb fc fd fe ff 00 01 02 03 04 05 06 07 08 ................
09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 18 ................
19 1a 1b 1c 1d 1e 1f 20 21 22 23 24 25 26 27 28 ....... !"#$%&'(
29 2a 2b 2c 2d 2e 2f 30 31 32 33 34 35 36 37 38 )*+,-./012345678
39 3a 3b 3c 3d 3e 3f 40 41 42 43 44 45 46 47 48 9:;<=>?@ABCDEFGH
49 4a 4b 4c 4d 4e 4f 50 51 52 53 54 55 56 57 58 IJKLMNOPQRSTUVWX
59 5a 5b 5c 5d 5e 5f 60 61 62 63 64 65 66 67 68 YZ[\]^_`abcdefgh
69 6a 6b 6c 6d 6e 6f 70 71 72 73 74 75 76 77 78 ijklmnopqrstuvwx
79 7a 7b 7c 7d 7e 7f 80 81 82 83 84 85 86 87 88 yz{|}~..........
89 8a 8b 8c 8d 8e 8f 90 91 92 93 94 95 96 97 98 ................
99 9a 9b 9c 9d 9e 9f a0 a1 a2 a3 a4 a5 a6 a7 a8 ................
a9 aa ab ac ad ae af b0 b1 b2 b3 b4 b5 b6 b7 b8 ................
b9 ba bb bc bd be bf c0 c1 c2 c3 c4 c5 c6 c7 c8 ................
c9 ca cb cc cd ce cf d0 d1 d2 d3 d4 d5 d6 d7 d8 ................
d9 da db dc dd de df e0 e1 e2 e3 e4 e5 e6 e7 e8 ................
e9 ea eb ec ed ee ef f0 f1 f2 f3 f4 f5 f6 f7 f8 ................
f9 fa fb fc fd 9e 72 59 e2 ......rY.
Lynn, et al. Expires December 18, 2016 [Page 24]
Internet-Draft IPv6 over MS/TP June 2016
Decompressed 6LoWPAN IPHC (558 bytes):
60 00 00 00 02 06 3a 3f aa aa 00 00 00 00 00 00 `.....:?........
00 00 00 00 00 00 00 01 aa aa 00 00 00 00 00 00 ................
00 00 00 ff fe 00 00 01 80 00 78 3f 2e e5 00 02 ..........x?....
e4 db e8 55 3b a0 04 00 08 09 0a 0b 0c 0d 0e 0f ...U;...........
10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ................
20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f !"#$%&'()*+,-./
30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f 0123456789:;<=>?
40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f PQRSTUVWXYZ[\]^_
60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f `abcdefghijklmno
70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f pqrstuvwxyz{|}~.
80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f ................
90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f ................
a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af ................
b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf ................
c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf ................
d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df ................
e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef ................
f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff ................
00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ................
10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ................
20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f !"#$%&'()*+,-./
30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f 0123456789:;<=>?
40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f PQRSTUVWXYZ[\]^_
60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f `abcdefghijklmno
70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f pqrstuvwxyz{|}~.
80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f ................
90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f ................
a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af ................
b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf ................
c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf ................
d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df ................
e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef ................
f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd ..............
Lynn, et al. Expires December 18, 2016 [Page 25]
Internet-Draft IPv6 over MS/TP June 2016
Authors' Addresses
Kerry Lynn (editor)
Verizon Labs
50 Sylvan Rd
Waltham , MA 02451
USA
Phone: +1 781 296 9722
Email: kerlyn@ieee.org
Jerry Martocci
Johnson Controls, Inc.
507 E. Michigan St
Milwaukee , WI 53202
USA
Phone: +1 414 524 4010
Email: jerald.p.martocci@jci.com
Carl Neilson
Delta Controls, Inc.
17850 56th Ave
Surrey , BC V3S 1C7
Canada
Phone: +1 604 575 5913
Email: cneilson@deltacontrols.com
Stuart Donaldson
Honeywell Automation & Control Solutions
6670 185th Ave NE
Redmond , WA 98052
USA
Email: stuart.donaldson@honeywell.com
Lynn, et al. Expires December 18, 2016 [Page 26]