draft-ietf-core-dynlink-04.txt   draft-ietf-core-dynlink-05.txt 
CoRE Working Group Z. Shelby CoRE Working Group Z. Shelby
Internet-Draft ARM Internet-Draft ARM
Intended status: Informational Z. Vial Intended status: Informational M. Vial
Expires: March 18, 2018 Schneider-Electric Expires: September 19, 2018 Schneider-Electric
M. Koster M. Koster
SmartThings SmartThings
C. Groves C. Groves
J. Zhu J. Zhu
Huawei Huawei
B. Silverajan, Ed. B. Silverajan, Ed.
Tampere University of Technology Tampere University of Technology
September 14, 2017 March 18, 2018
Dynamic Resource Linking for Constrained RESTful Environments Dynamic Resource Linking for Constrained RESTful Environments
draft-ietf-core-dynlink-04 draft-ietf-core-dynlink-05
Abstract Abstract
For CoAP [RFC7252] Dynamic linking of state updates between For CoAP [RFC7252] Dynamic linking of state updates between
resources, either on an endpoint or between endpoints, is defined resources, either on an endpoint or between endpoints, is defined
with the concept of Link Bindings. This specification defines with the concept of Link Bindings. This specification defines
conditional observation attributes that work with Link Bindings or conditional observation attributes that work with Link Bindings or
with CoAP Observe [RFC7641]. with CoAP Observe [RFC7641].
Editor's note: Editor's note:
skipping to change at page 1, line 40 skipping to change at page 1, line 40
core-wg/dynlink core-wg/dynlink
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 18, 2018. This Internet-Draft will expire on September 19, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Link Bindings . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Link Bindings . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Binding Methods . . . . . . . . . . . . . . . . . . . . . 4 3.1. Binding Methods . . . . . . . . . . . . . . . . . . . . . 4
3.1.1. Polling . . . . . . . . . . . . . . . . . . . . . . . 5 3.1.1. Polling . . . . . . . . . . . . . . . . . . . . . . . 5
3.1.2. Observe . . . . . . . . . . . . . . . . . . . . . . . 5 3.1.2. Observe . . . . . . . . . . . . . . . . . . . . . . . 5
3.1.3. Push . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1.3. Push . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2. Link Relation . . . . . . . . . . . . . . . . . . . . . . 6 3.2. Link Relation . . . . . . . . . . . . . . . . . . . . . . 6
3.3. Binding Attributes . . . . . . . . . . . . . . . . . . . 6 3.3. Binding Attributes . . . . . . . . . . . . . . . . . . . 6
3.3.1. Bind Method (bind) . . . . . . . . . . . . . . . . . 6 3.3.1. Bind Method (bind) . . . . . . . . . . . . . . . . . 6
3.3.2. Minimum Period (pmin) . . . . . . . . . . . . . . . . 6 3.3.2. Minimum Period (pmin) . . . . . . . . . . . . . . . . 6
3.3.3. Maximum Period (pmax) . . . . . . . . . . . . . . . . 7 3.3.3. Maximum Period (pmax) . . . . . . . . . . . . . . . . 7
3.3.4. Change Step (st) . . . . . . . . . . . . . . . . . . 7 3.3.4. Change Step (st) . . . . . . . . . . . . . . . . . . 7
3.3.5. Greater Than (gt) . . . . . . . . . . . . . . . . . . 7 3.3.5. Greater Than (gt) . . . . . . . . . . . . . . . . . . 7
3.3.6. Less Than (lt) . . . . . . . . . . . . . . . . . . . 7 3.3.6. Less Than (lt) . . . . . . . . . . . . . . . . . . . 8
3.3.7. Attribute Interactions . . . . . . . . . . . . . . . 8 3.3.7. Notification Band (band) . . . . . . . . . . . . . . 8
4. Binding Table . . . . . . . . . . . . . . . . . . . . . . . . 8 3.3.8. Attribute Interactions . . . . . . . . . . . . . . . 9
4.1. Binding Interface Description . . . . . . . . . . . . . . 8 4. Binding Table . . . . . . . . . . . . . . . . . . . . . . . . 10
4.2. Resource Observation Attributes . . . . . . . . . . . . . 9 4.1. Binding Interface Description . . . . . . . . . . . . . . 10
5. Security Considerations . . . . . . . . . . . . . . . . . . . 10 4.2. Resource Observation Attributes . . . . . . . . . . . . . 11
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 5. Security Considerations . . . . . . . . . . . . . . . . . . . 12
6.1. Interface Description . . . . . . . . . . . . . . . . . . 11 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
6.2. Link Relation Type . . . . . . . . . . . . . . . . . . . 11 6.1. Interface Description . . . . . . . . . . . . . . . . . . 13
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 6.2. Link Relation Type . . . . . . . . . . . . . . . . . . . 13
8. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 12 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 8. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 14
9.1. Normative References . . . . . . . . . . . . . . . . . . 13 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . 13 9.1. Normative References . . . . . . . . . . . . . . . . . . 15
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 13 9.2. Informative References . . . . . . . . . . . . . . . . . 15
A.1. Greater Than (gt) example . . . . . . . . . . . . . . . . 14 Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 16
A.2. Greater Than (gt) and Period Max (pmax) example . . . . . 14 A.1. Greater Than (gt) example . . . . . . . . . . . . . . . . 16
A.2. Greater Than (gt) and Period Max (pmax) example . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction 1. Introduction
IETF Standards for machine to machine communication in constrained IETF Standards for machine to machine communication in constrained
environments describe a REST protocol and a set of related environments describe a REST protocol and a set of related
information standards that may be used to represent machine data and information standards that may be used to represent machine data and
machine metadata in REST interfaces. CoRE Link-format is a standard machine metadata in REST interfaces. CoRE Link-format is a standard
for doing Web Linking [RFC5988] in constrained environments. for doing Web Linking [RFC5988] in constrained environments.
This specification introduces the concept of a Link Binding, which This specification introduces the concept of a Link Binding, which
skipping to change at page 3, line 47 skipping to change at page 3, line 47
resource and a destination resource, over which state information resource and a destination resource, over which state information
is synchronized. is synchronized.
State Synchronization: Depending on the binding method (Polling, State Synchronization: Depending on the binding method (Polling,
Observe, Push) different REST methods may be used to synchronize Observe, Push) different REST methods may be used to synchronize
the resource values between a source and a destination. The the resource values between a source and a destination. The
process of using a REST method to achieve this is defined as process of using a REST method to achieve this is defined as
"State Synchronization". The endpoint triggering the state "State Synchronization". The endpoint triggering the state
synchronization is the synchronization initiator. synchronization is the synchronization initiator.
Notification Band: A resource value range that results in state
sychronization. The value range may be bounded by a minimum and
maximum value or may be unbounded having either a minimum or
maximum value.
3. Link Bindings 3. Link Bindings
In a M2M RESTful environment, endpoints may directly exchange the In a M2M RESTful environment, endpoints may directly exchange the
content of their resources to operate the distributed system. For content of their resources to operate the distributed system. For
example, a light switch may supply on-off control information that example, a light switch may supply on-off control information that
may be sent directly to a light resource for on-off control. may be sent directly to a light resource for on-off control.
Beforehand, a configuration phase is necessary to determine how the Beforehand, a configuration phase is necessary to determine how the
resources of the different endpoints are related to each other. This resources of the different endpoints are related to each other. This
can be done either automatically using discovery mechanisms or by can be done either automatically using discovery mechanisms or by
means of human intervention and a so-called commissioning tool. In means of human intervention and a so-called commissioning tool. In
this specification the abstract relationship between two resources is this specification the abstract relationship between two resources is
called a link Binding. The configuration phase necessitates the called a link Binding. The configuration phase necessitates the
exchange of binding information so a format recognized by all CoRE exchange of binding information so a format recognized by all CoRE
endpoints is essential. This specification defines a format based on endpoints is essential. This specification defines a format based on
the CoRE Link-Format to represent binding information along with the the CoRE Link-Format to represent binding information along with the
rules to define a binding method which is a specialized relationship rules to define a binding method which is a specialized relationship
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| | | | | | | |
| Minimum Period (s) | pmin | xsd:integer (>0) | | Minimum Period (s) | pmin | xsd:integer (>0) |
| | | | | | | |
| Maximum Period (s) | pmax | xsd:integer (>0) | | Maximum Period (s) | pmax | xsd:integer (>0) |
| | | | | | | |
| Change Step | st | xsd:decimal (>0) | | Change Step | st | xsd:decimal (>0) |
| | | | | | | |
| Greater Than | gt | xsd:decimal | | Greater Than | gt | xsd:decimal |
| | | | | | | |
| Less Than | lt | xsd:decimal | | Less Than | lt | xsd:decimal |
| | | |
| Notification Band | band | xsd:boolean |
+--------------------+-----------+------------------+ +--------------------+-----------+------------------+
Table 2: Binding Attributes Summary Table 2: Binding Attributes Summary
3.3.1. Bind Method (bind) 3.3.1. Bind Method (bind)
This is the identifier of a binding method which defines the rules to This is the identifier of a binding method which defines the rules to
synchronize the destination resource. This attribute is mandatory. synchronize the destination resource. This attribute is mandatory.
3.3.2. Minimum Period (pmin) 3.3.2. Minimum Period (pmin)
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When present, Less Than indicates the lower limit value the resource When present, Less Than indicates the lower limit value the resource
value SHOULD cross before triggering a new state synchronization. value SHOULD cross before triggering a new state synchronization.
State synchronization only occurs when the resource value is less State synchronization only occurs when the resource value is less
than the specified lower limit value. The actual resource value is than the specified lower limit value. The actual resource value is
used for the synchronization rather than the lt value. If the value used for the synchronization rather than the lt value. If the value
continues to fall no new state synchronizations are generated as a continues to fall no new state synchronizations are generated as a
result of lt. If the value rises above the lower limit value and result of lt. If the value rises above the lower limit value and
then drops below the lower limit then a new state synchronization is then drops below the lower limit then a new state synchronization is
generated. generated.
3.3.7. Attribute Interactions 3.3.7. Notification Band (band)
The notification band attribute allows a bounded or unbounded (based
on a minimum or maximum) value range that may trigger multiple state
synchronizations. This enables use cases where different ranges
results in differing behaviour. For example: monitoring the
temperature of machinery. Whilst the temperature is in the normal
operating range only periodic observations are needed. However as
the temperature moves to more abnormal ranges more frequent
synchronization/reporting may be needed.
Without a notification band, a transition across a less than (lt), or
greater than (gt) limit only generates one notification. This means
that it is not possible to describe a case where multiple
notifications are sent so long as the limit is exceeded.
The band attribute works as a modifier to the behaviour of gt and lt.
Therefore, if band is present in a query, gt, lt or both, MUST be
included.
When band is present with the lt attribute, it defines the lower
bound for the notification band (notification band minimum). State
synchronization occurs when the resource value is equal to or above
the notification band minimum. If lt is not present there is no
minimum value for the band.
When band is present with the gt attribute, it defines the upper
bound for the notification band (notification band maximum). State
synchronization occurs when the resource value is equal to or below
the notification band maximum. If gt is not present there is no
maximum value for the band.
3.3.8. Attribute Interactions
Pmin, pmax, st, gt and lt may be present in the same query. Pmin, pmax, st, gt and lt may be present in the same query.
If pmin and pmax are present in a query then they take precedence If pmin and pmax are present in a query then they take precedence
over the other parameters. Thus even if st, gt or lt are met, if over the other parameters. Thus even if st, gt or lt are met, if
pmin has not been exceeded then no state synchronization occurs. pmin has not been exceeded then no state synchronization occurs.
Likewise if st, gt or lt have not been met and pmax time has expired Likewise if st, gt or lt have not been met and pmax time has expired
then state synchronization occurs. The current value of the resource then state synchronization occurs. The current value of the resource
is used for the synchronization. If pmin time is exceeded and st, gt is used for the synchronization. If pmin time is exceeded and st, gt
or lt are met then the current value of the resource is synchronized. or lt are met then the current value of the resource is synchronized.
If st is also included, a state synchronization resulting from pmin If st is also included, a state synchronization resulting from pmin
or pmax updates STinit with the synchronized value. or pmax updates STinit with the synchronized value.
If gt and lt are included gt MUST be greater than lt otherwise an If gt and lt are included gt MUST be greater than lt otherwise an
error CoAP error code 4.00 "Bad Request" (or equivalent) MUST be error CoAP error code 4.00 "Bad Request" (or equivalent) MUST be
returned. returned.
If st is included in a query with a gt or lt attribute then state If st is included in a query with a gt or lt attribute then state
synchronizations occur only when the conditions described by st AND synchronizations occur only when the conditions described by st AND
gt or st AND gl are met. gt or st AND lt are met.
To enable an notification band at least the notification band minimum
or maximum MUST be set. If both the notification band minimum and
maximum are set then a finite band is specified. State
synchronization occurs whenever the resource value is between the
notification band minimum and maximum or is equal to the notification
band minimum or maximum. If only the notification band minimum or
maximum is set then the band has an open bound. That is all values
above the notification band minimum or all values below the
notification band maximum will be synchronized.
When using multiple resource bindings (e.g. multiple Observations of
resource) with different bands, consideration should be given to the
resolution of the resource value when setting sequential bands. For
example: Given BandA (Abmn=10, Bbmx=20) and BandB (Bbmn=21, Bbmx=30).
If the resource value returns an integer then notifications for
values between and inclusive of 10 and 30 will be triggered. Whereas
if the resolution is to one decimal point (0.1) then notifications
for values 20.1 to 20.9 will not be triggered.
Note: The use of the notification band minimum and maximum allow for
a synchronization whenever a change in the resource value occurs.
Theoretically this could occur in-line with the server internal
sample period for the determining the resource value. Implementors
SHOULD consider the resolution needed before updating the resource,
e.g. updating the resource when a temperature sensor value changes by
0.001 degree versus 1 degree.
If pmin and pmax are present in a query then they take precedence
over the other parameters. Thus even if the notification band
minimum and maximum are met if pmin has not been exceeded then no
state synchronization occurs. Likewise if the notification band
minimum and maximum have not been met and pmax time has expired then
state synchronization occurs. The current value of the resource is
used for the synchronization. If pmin time is exceeded and the
notification band minimum and maximum are met then the current value
of the resource is synchronized. If st is also included, a state
synchronization resulting from pmin or pmax updates STinit with the
synchronized value. If change step (st) is included in a query with
the notification band minimum or maximum then state synchronization
will occur whilst the resource value is in the notification band AND
the resource value differs from STinit by the change step.
4. Binding Table 4. Binding Table
The binding table is a special resource that gives access to the The binding table is a special resource that gives access to the
bindings on a endpoint. A binding table resource MUST support the bindings on a endpoint. A binding table resource MUST support the
Binding interface defined below. A profile SHOULD allow only one Binding interface defined below. A profile SHOULD allow only one
resource table per endpoint. resource table per endpoint.
4.1. Binding Interface Description 4.1. Binding Interface Description
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specification and marked as Observable in its link description SHOULD specification and marked as Observable in its link description SHOULD
support these observation parameters. The Change Step parameter can support these observation parameters. The Change Step parameter can
only be supported on resources with an atomic numeric value. only be supported on resources with an atomic numeric value.
These query parameters MUST be treated as resources that are read These query parameters MUST be treated as resources that are read
using GET and updated using PUT, and MUST NOT be included in the using GET and updated using PUT, and MUST NOT be included in the
Observe request. Multiple parameters MAY be updated at the same time Observe request. Multiple parameters MAY be updated at the same time
by including the values in the query string of a PUT. Before being by including the values in the query string of a PUT. Before being
updated, these parameters have no default value. updated, these parameters have no default value.
+----------------+------------------+------------------+ +-------------------+------------------+------------------+
| Resource | Parameter | Data Format | | Attribute Name | Parameter | Data Format |
+----------------+------------------+------------------+ +-------------------+------------------+------------------+
| Minimum Period | /{resource}?pmin | xsd:integer (>0) | | Minimum Period | /{resource}?pmin | xsd:integer (>0) |
| | | | | | | |
| Maximum Period | /{resource}?pmax | xsd:integer (>0) | | Maximum Period | /{resource}?pmax | xsd:integer (>0) |
| | | | | | | |
| Change Step | /{resource}?st | xsd:decimal (>0) | | Change Step | /{resource}?st | xsd:decimal (>0) |
| | | | | | | |
| Less Than | /{resource}?lt | xsd:decimal | | Less Than | /{resource}?lt | xsd:decimal |
| | | | | | | |
| Greater Than | /{resource}?gt | xsd:decimal | | Greater Than | /{resource}?gt | xsd:decimal |
+----------------+------------------+------------------+ | | | |
| Notification Band | /{resource}?band | xsd:boolean |
+-------------------+------------------+------------------+
Table 4: Resource Observation Attribute Summary Table 4: Resource Observation Attribute Summary
inimum Period: As per Section 3.3.2 Minimum Period: As per Section 3.3.2
aximum Period: As per Section 3.3.3 Maximum Period: As per Section 3.3.3
Change Step: As per Section 3.3.4 Change Step: As per Section 3.3.4
Greater Than: As per Section 3.3.5 Greater Than: As per Section 3.3.5
Less Than: As per Section 3.3.6 Less Than: As per Section 3.3.6
Notification Band: As per Section 3.3.7
5. Security Considerations 5. Security Considerations
An implementation of a client needs to be prepared to deal with An implementation of a client needs to be prepared to deal with
responses to a request that differ from what is specified in this responses to a request that differ from what is specified in this
specification. A server implementing what the client thinks is a specification. A server implementing what the client thinks is a
resource with one of these interface descriptions could return resource with one of these interface descriptions could return
malformed representations and response codes either by accident or malformed representations and response codes either by accident or
maliciously. A server sending maliciously malformed responses could maliciously. A server sending maliciously malformed responses could
attempt to take advantage of a poorly implemented client for example attempt to take advantage of a poorly implemented client for example
to crash the node or perform denial of service. to crash the node or perform denial of service.
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Acknowledgement is given to colleagues from the SENSEI project who Acknowledgement is given to colleagues from the SENSEI project who
were critical in the initial development of the well-known REST were critical in the initial development of the well-known REST
interface concept, to members of the IPSO Alliance where further interface concept, to members of the IPSO Alliance where further
requirements for interface types have been discussed, and to Szymon requirements for interface types have been discussed, and to Szymon
Sasin, Cedric Chauvenet, Daniel Gavelle and Carsten Bormann who have Sasin, Cedric Chauvenet, Daniel Gavelle and Carsten Bormann who have
provided useful discussion and input to the concepts in this provided useful discussion and input to the concepts in this
specification. specification.
8. Changelog 8. Changelog
draft-ietf-core-dynlink-05
o Addition of a band modifier for gt and lt, adapted from draft-
groves-core-obsattr
o Removed statement prescribing gt MUST be greater than lt
draft-ietf-core-dynlink-03 draft-ietf-core-dynlink-03
o General: Reverted to using "gt" and "lt" from "gth" and "lth" for o General: Reverted to using "gt" and "lt" from "gth" and "lth" for
this draft owing to concerns raised that the attributes are this draft owing to concerns raised that the attributes are
already used in LwM2M with the original names "gt" and "lt". already used in LwM2M with the original names "gt" and "lt".
o New author and editor added. o New author and editor added.
draft-ietf-core-dynlink-02 draft-ietf-core-dynlink-02
skipping to change at page 13, line 22 skipping to change at page 15, line 27
linking functionality in I.D.ietf-core-interfaces-05. linking functionality in I.D.ietf-core-interfaces-05.
o The WADL description has been dropped in favour of a thorough o The WADL description has been dropped in favour of a thorough
textual description of the REST API. textual description of the REST API.
9. References 9. References
9.1. Normative References 9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/ Requirement Levels", BCP 14, RFC 2119,
RFC2119, March 1997, <https://www.rfc-editor.org/info/ DOI 10.17487/RFC2119, March 1997,
rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC5988] Nottingham, M., "Web Linking", RFC 5988, DOI 10.17487/ [RFC5988] Nottingham, M., "Web Linking", RFC 5988,
RFC5988, October 2010, <https://www.rfc-editor.org/info/ DOI 10.17487/RFC5988, October 2010,
rfc5988>. <https://www.rfc-editor.org/info/rfc5988>.
[RFC6690] Shelby, Z., "Constrained RESTful Environments (CoRE) Link [RFC6690] Shelby, Z., "Constrained RESTful Environments (CoRE) Link
Format", RFC 6690, DOI 10.17487/RFC6690, August 2012, Format", RFC 6690, DOI 10.17487/RFC6690, August 2012,
<https://www.rfc-editor.org/info/rfc6690>. <https://www.rfc-editor.org/info/rfc6690>.
9.2. Informative References 9.2. Informative References
[RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained [RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
Application Protocol (CoAP)", RFC 7252, DOI 10.17487/ Application Protocol (CoAP)", RFC 7252,
RFC7252, June 2014, <https://www.rfc-editor.org/info/ DOI 10.17487/RFC7252, June 2014,
rfc7252>. <https://www.rfc-editor.org/info/rfc7252>.
[RFC7641] Hartke, K., "Observing Resources in the Constrained [RFC7641] Hartke, K., "Observing Resources in the Constrained
Application Protocol (CoAP)", RFC 7641, DOI 10.17487/ Application Protocol (CoAP)", RFC 7641,
RFC7641, September 2015, <https://www.rfc-editor.org/info/ DOI 10.17487/RFC7641, September 2015,
rfc7641>. <https://www.rfc-editor.org/info/rfc7641>.
Appendix A. Examples Appendix A. Examples
This appendix provides some examples of the use of binding attribute This appendix provides some examples of the use of binding attribute
/ observe attributes. / observe attributes.
Note: For brevity the only the method or response code is shown in Note: For brevity the only the method or response code is shown in
the header field. the header field.
A.1. Greater Than (gt) example A.1. Greater Than (gt) example
skipping to change at page 16, line 26 skipping to change at page 18, line 35
USA USA
Email: michael.koster@smartthings.com Email: michael.koster@smartthings.com
Christian Groves Christian Groves
Huawei Huawei
Australia Australia
Email: cngroves.std@gmail.com Email: cngroves.std@gmail.com
Julian Zhu Jintao Zhu
Huawei Huawei
No.127 Jinye Road, Huawei Base, High-Tech Development District No.127 Jinye Road, Huawei Base, High-Tech Development District
Xi'an, Shaanxi Province Xi'an, Shaanxi Province
China China
Email: jintao.zhu@huawei.com Email: jintao.zhu@huawei.com
Bilhanan Silverajan (editor) Bilhanan Silverajan (editor)
Tampere University of Technology Tampere University of Technology
Korkeakoulunkatu 10 Korkeakoulunkatu 10
Tampere FI-33720 Tampere FI-33720
Finland Finland
Email: bilhanan.silverajan@tut.fi Email: bilhanan.silverajan@tut.fi
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