Internet DRAFT - draft-bormann-6lo-coap-802-15-ie
draft-bormann-6lo-coap-802-15-ie
6Lo C. Bormann
Internet-Draft Universitaet Bremen TZI
Intended status: Standards Track April 03, 2016
Expires: October 5, 2016
Constrained Application Protocol (CoAP) over IEEE 802.15.4 Information
Element for IETF
draft-bormann-6lo-coap-802-15-ie-00.txt
Abstract
IEEE Std. 802.15.4-2015 defines Information Elements (IE), and draft-
kivinen-802-15-ie defines a framework for using these IEs in IETF
protocols.
The present specification defines a way to transport CoAP messages in
IEs. This can be used to perform CoAP exchanges with neighboring
IEEE 802.15.4 nodes before there is IP connectivity, e.g., to
configure that IP connectivity.
draft-wang-6tisch-6top-coapie demonstrates example applications of
this for 6TiSCH. Other areas of application are conceivable even in
classic 6LoWPAN 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 October 5, 2016.
Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
Bormann Expires October 5, 2016 [Page 1]
Internet-Draft CoAP over IETF IE April 2016
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
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
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2
2. CoAP over IETF IE . . . . . . . . . . . . . . . . . . . . . . 2
3. Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
7.1. Normative References . . . . . . . . . . . . . . . . . . 4
7.2. Informative References . . . . . . . . . . . . . . . . . 4
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
(See abstract for now.)
1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in RFC
2119 [RFC2119].
In this specification, the term "byte" is used in its now customary
sense as a synonym for "octet".
2. CoAP over IETF IE
The format of the IETF IE is defined in [I-D.kivinen-802-15-ie] as
follows:
Bormann Expires October 5, 2016 [Page 2]
Internet-Draft CoAP over IETF IE April 2016
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Type ID | |
+-+-+-+-+-+-+-+-+ |
~ Sub-Type Content ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IETF IE Subtype Format
Here, Sub-Type ID is the IANA allocated number specifying the sub-
type of the IETF IE. The CoAP message is embedded in the IETF IE as
follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Ver| T | TKL | Code | Message ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Token (if any, TKL bytes) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Options (if any) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1 1 1 1 1 1 1 1| Payload (if any) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IETF IE Subtype Format for CoAP
This means that the combinations of Ver, T, TKL used by CoAP need to
be allocated as Sub-Type IDs. Ver is always 1; T can be 0, 1, 2, 3,
and TKL can be between 0 and 8 for T in 0..2 and 0 only for T = 3.
This means that 3*9+1 = 28 Sub-Type IDs are needed.
3. Benefits
Allocating 11 % of the code points (28 out of the 256) available for
IETF IEs may seem like a large chunk. However, it enables the
embedding of CoAP messages into IEs in an efficient way; any smaller
allocation would need additional complexity for variable length
encoding or would even always need an additional byte of overhead.
4. IANA Considerations
This specification requests IANA to assign the following 28 code
points in the registry for IETF IE Sub-type IDs to this
specification:
Bormann Expires October 5, 2016 [Page 3]
Internet-Draft CoAP over IETF IE April 2016
+--------+-------------+
| Value | Sub-type ID |
+--------+-------------+
| 64-72 | CoAP |
| 80-88 | CoAP |
| 96-104 | CoAP |
| 112 | CoAP |
+--------+-------------+
5. Security Considerations
The security considerations of [I-D.kivinen-802-15-ie] apply.
Specifically, this means that object security (intrinsic in the
resources accessed or explicit on the CoAP level) may be required.
6. Acknowledgments
Much of the text here is taken from [I-D.kivinen-802-15-ie].
7. References
7.1. Normative References
[I-D.kivinen-802-15-ie]
Kivinen, T. and P. Kinney, "IEEE 802.15.4 Information
Element for IETF", draft-kivinen-802-15-ie-00 (work in
progress), March 2016.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
7.2. Informative References
[I-D.wang-6tisch-6top-coapie]
Wang, Q., Vilajosana, X., Watteyne, T., Sudhaakar, R., and
P. Zand, "Transporting CoAP Messages over IEEE802.15.4e
Information Elements", draft-wang-6tisch-6top-coapie-01
(work in progress), July 2015.
Author's Address
Bormann Expires October 5, 2016 [Page 4]
Internet-Draft CoAP over IETF IE April 2016
Carsten Bormann
Universitaet Bremen TZI
Postfach 330440
Bremen D-28359
Germany
Phone: +49-421-218-63921
Email: cabo@tzi.org
Bormann Expires October 5, 2016 [Page 5]
