draft-ietf-core-dynlink-03.txt   draft-ietf-core-dynlink-04.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 Z. Vial
Expires: September 14, 2017 Schneider-Electric Expires: March 18, 2018 Schneider-Electric
M. Koster M. Koster
SmartThings SmartThings
C. Groves C. Groves
J. Zhu
Huawei Huawei
March 13, 2017 B. Silverajan, Ed.
Tampere University of Technology
September 14, 2017
Dynamic Resource Linking for Constrained RESTful Environments Dynamic Resource Linking for Constrained RESTful Environments
draft-ietf-core-dynlink-03 draft-ietf-core-dynlink-04
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 44 skipping to change at page 1, line 47
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 http://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 September 14, 2017. This Internet-Draft will expire on March 18, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 35 skipping to change at page 2, line 35
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 (gth) . . . . . . . . . . . . . . . . . 7 3.3.5. Greater Than (gt) . . . . . . . . . . . . . . . . . . 7
3.3.6. Less Than (lth) . . . . . . . . . . . . . . . . . . . 7 3.3.6. Less Than (lt) . . . . . . . . . . . . . . . . . . . 7
3.3.7. Attribute Interactions . . . . . . . . . . . . . . . 8 3.3.7. Attribute Interactions . . . . . . . . . . . . . . . 8
4. Binding Table . . . . . . . . . . . . . . . . . . . . . . . . 8 4. Binding Table . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1. Binding Interface Description . . . . . . . . . . . . . . 8 4.1. Binding Interface Description . . . . . . . . . . . . . . 8
4.2. Resource Observation Attributes . . . . . . . . . . . . . 9 4.2. Resource Observation Attributes . . . . . . . . . . . . . 9
5. Security Considerations . . . . . . . . . . . . . . . . . . . 11 5. Security Considerations . . . . . . . . . . . . . . . . . . . 10
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
6.1. Interface Description . . . . . . . . . . . . . . . . . . 11 6.1. Interface Description . . . . . . . . . . . . . . . . . . 11
6.2. Link Relations Type . . . . . . . . . . . . . . . . . . . 11 6.2. Link Relation Type . . . . . . . . . . . . . . . . . . . 11
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11
8. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 12 8. Changelog . . . . . . . . . . . . . . . . . . . . . . . . . . 12
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
9.1. Normative References . . . . . . . . . . . . . . . . . . 13 9.1. Normative References . . . . . . . . . . . . . . . . . . 13
9.2. Informative References . . . . . . . . . . . . . . . . . 13 9.2. Informative References . . . . . . . . . . . . . . . . . 13
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 14 Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 13
A.1. Greater Than (gth) example . . . . . . . . . . . . . . . 14 A.1. Greater Than (gt) example . . . . . . . . . . . . . . . . 14
A.2. Greater Than (gth) and Period Max (pmax) example . . . . 14 A.2. Greater Than (gt) and Period Max (pmax) example . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
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.
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| Attribute | Parameter | Value | | Attribute | Parameter | Value |
+--------------------+-----------+------------------+ +--------------------+-----------+------------------+
| Binding method | bind | xsd:string | | Binding method | bind | xsd:string |
| | | | | | | |
| 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 | gth | xsd:decimal | | Greater Than | gt | xsd:decimal |
| | | | | | | |
| Less Than | lth | xsd:decimal | | Less Than | lt | xsd:decimal |
+--------------------+-----------+------------------+ +--------------------+-----------+------------------+
Table 2: Binding Attributes Summary Table 2: Binding Attributes Summary
**Editor's note: Naming of lth and gth to be confirmed at IETF98.
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)
When present, the minimum period indicates the minimum time to wait When present, the minimum period indicates the minimum time to wait
(in seconds) before triggering a new state synchronization (even if (in seconds) before triggering a new state synchronization (even if
it has changed). In the absence of this parameter, the minimum it has changed). In the absence of this parameter, the minimum
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synchronization occurs. STinit is then set to the state synchronization occurs. STinit is then set to the state
synchronization value and new state synchronizations are based on a synchronization value and new state synchronizations are based on a
change step against this value. The change step MUST be greater than change step against this value. The change step MUST be greater than
zero otherwise the receiver MUST return a CoAP error code 4.00 "Bad zero otherwise the receiver MUST return a CoAP error code 4.00 "Bad
Request" (or equivalent). Request" (or equivalent).
Note: Due to the state synchronization based update of STint it may Note: Due to the state synchronization based update of STint it may
result in that resource value received in two sequential state result in that resource value received in two sequential state
synchronizations differs by more than st. synchronizations differs by more than st.
3.3.5. Greater Than (gth) 3.3.5. Greater Than (gt)
When present, Greater Than indicates the upper limit value the When present, Greater Than indicates the upper limit value the
resource value SHOULD cross before triggering a new state resource value SHOULD cross before triggering a new state
synchronization. State synchronization only occurs when the resource synchronization. State synchronization only occurs when the resource
value exceeds the specified upper limit value. The actual resource value exceeds the specified upper limit value. The actual resource
value is used for the synchronization rather than the gth value. If value is used for the synchronization rather than the gt value. If
the value continues to rise, no new state synchronizations are the value continues to rise, no new state synchronizations are
generated as a result of gth. If the value drops below the upper generated as a result of gt. If the value drops below the upper
limit value and then exceeds the upper limit then a new state limit value and then exceeds the upper limit then a new state
synchronization is generated. synchronization is generated.
3.3.6. Less Than (lth) 3.3.6. Less Than (lt)
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 lth 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 lth. 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. Attribute Interactions
Pmin, pmax, st, gth and lth 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, gth or lth 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, gth or lth have not been met and pmax time has Likewise if st, gt or lt have not been met and pmax time has expired
expired then state synchronization occurs. The current value of the then state synchronization occurs. The current value of the resource
resource is used for the synchronization. If pmin time is exceeded is used for the synchronization. If pmin time is exceeded and st, gt
and st, gth or lth are met then the current value of the resource is or lt are met then the current value of the resource is synchronized.
synchronized. If st is also included, a state synchronization If st is also included, a state synchronization resulting from pmin
resulting from pmin or pmax updates STinit with the synchronized or pmax updates STinit with the synchronized value.
value.
If gth and lth are included gth MUST be greater than lth 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 gth or lth 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
gth or st AND gl are met. gt or st AND gl are met.
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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| Binding | core.bnd | GET, POST, DELETE | link-format | | Binding | core.bnd | GET, POST, DELETE | link-format |
+-----------+----------+-------------------+-----------------+ +-----------+----------+-------------------+-----------------+
Table 3: Binding Interface Description Table 3: Binding Interface Description
The Binding interface is used to manipulate a binding table. A The Binding interface is used to manipulate a binding table. A
request with a POST method and a content format of application/link- request with a POST method and a content format of application/link-
format simply appends new bindings to the table. All links in the format simply appends new bindings to the table. All links in the
payload MUST have a relation type "boundTo". A GET request simply payload MUST have a relation type "boundTo". A GET request simply
returns the current state of a binding table whereas a DELETE request returns the current state of a binding table whereas a DELETE request
empties the table. Individual entries may be dreeleted from the empties the table. Individual entries may be deleted from the table
table by specifying the resource path in a DELETE request. by specifying the resource path in a DELETE request.
The following example shows requests for adding, retrieving and The following example shows requests for adding, retrieving and
deleting bindings in a binding table. deleting bindings in a binding table.
Req: POST /bnd/ (Content-Format: application/link-format) Req: POST /bnd/ (Content-Format: application/link-format)
<coap://sensor.example.com/s/switch>; <coap://sensor.example.com/s/light>;
rel="boundto";anchor="/a/light";bind="obs";pmin="10";pmax="60" rel="boundto";anchor="/a/light";bind="obs";pmin="10";pmax="60"
Res: 2.04 Changed Res: 2.04 Changed
Req: GET /bnd/ Req: GET /bnd/
Res: 2.05 Content (application/link-format) Res: 2.05 Content (application/link-format)
<coap://sensor.example.com/s/switch>; <coap://sensor.example.com/s/light>;
rel="boundto";anchor="/a/light";bind="obs";pmin="10";pmax="60" rel="boundto";anchor="/a/light";bind="obs";pmin="10";pmax="60"
Req: DELETE /bnd/a/switch Req: DELETE /bnd/a/light
Res: 2.04 Changed Res: 2.04 Changed
Req: DELETE /bnd/ Req: DELETE /bnd/
Res: 2.04 Changed Res: 2.04 Changed
Figure 1: Binding Interface Example Figure 1: Binding Interface Example
4.2. Resource Observation Attributes 4.2. Resource Observation Attributes
When resource interfaces following this specification are made When resource interfaces following this specification are made
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notifications as a result. In addition, a set of query string notifications as a result. In addition, a set of query string
parameters are defined here to allow a client to control how often a parameters are defined here to allow a client to control how often a
client is interested in receiving notifications and how much a client is interested in receiving notifications and how much a
resource value should change for the new representation to be resource value should change for the new representation to be
interesting. These query parameters are described in the following interesting. These query parameters are described in the following
table. A resource using an interface description defined in this table. A resource using an interface description defined in this
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.
*Editor's note: There is a proposal to use the query parameters on
the GET Observe as the default pattern. This allows multiple
observations of the same resource. The PUT behaviour below would be
treated as a legacy option. This will be discussed at IETF98.*
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 | | Resource | 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}?lth | xsd:decimal | | Less Than | /{resource}?lt | xsd:decimal |
| | | | | | | |
| Greater Than | /{resource}?gth | xsd:decimal | | Greater Than | /{resource}?gt | xsd:decimal |
+----------------+------------------+------------------+ +----------------+------------------+------------------+
Table 4: Resource Observation Attribute Summary Table 4: Resource Observation Attribute Summary
Minimum Period: As per Section 3.3.2 inimum Period: As per Section 3.3.2
Maximum Period: As per Section 3.3.3 aximum 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
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
skipping to change at page 11, line 35 skipping to change at page 11, line 26
Description: The binding interface is used to manipulate a binding Description: The binding interface is used to manipulate a binding
table which describes the link bindings between source and table which describes the link bindings between source and
destination resources for the purposes of synchronizing their destination resources for the purposes of synchronizing their
content. content.
Reference: This specification. Note to RFC editor: please insert the Reference: This specification. Note to RFC editor: please insert the
RFC of this specification. RFC of this specification.
Notes: None Notes: None
6.2. Link Relations Type 6.2. Link Relation Type
This specification registers the new "bounto" link relation type as This specification registers the new "boundto" link relation type as
per [RFC5988]. per [RFC5988].
Relation Name: boundto Relation Name: boundto
Description: The purpose of a boundto relation type is to indicate Description: The purpose of a boundto relation type is to indicate
that there is a binding between a source resource and a that there is a binding between a source resource and a
destination resource for the purposes of synchronizing their destination resource for the purposes of synchronizing their
content. content.
Reference: This specification. Note to RFC editor: please insert Reference: This specification. Note to RFC editor: please insert
skipping to change at page 12, line 19 skipping to change at page 12, line 11
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-03 draft-ietf-core-dynlink-03
o Section 4.2: Update the Href to use "switch" instead of "light". o General: Reverted to using "gt" and "lt" from "gth" and "lth" for
this draft owing to concerns raised that the attributes are
already used in LwM2M with the original names "gt" and "lt".
o General: Added editor's notes for issues to be resolved at IETF98. o New author and editor added.
draft-ietf-core-dynlink-02 draft-ietf-core-dynlink-02
o General: Changed the name of the greater than attribute "gt" to o General: Changed the name of the greater than attribute "gt" to
"gth" and the name of the less than attribute "lt" to "lth" due to "gth" and the name of the less than attribute "lt" to "lth" due to
conlict with the core resource directory draft lifetime "lt" conlict with the core resource directory draft lifetime "lt"
attribute. attribute.
o Clause 6.1: Addressed the editor's note by changing the link o Clause 6.1: Addressed the editor's note by changing the link
target attribute to "core.binding". target attribute to "core.binding".
skipping to change at page 13, line 27 skipping to change at page 13, line 22
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, Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
DOI 10.17487/RFC2119, March 1997, RFC2119, March 1997, <https://www.rfc-editor.org/info/
<http://www.rfc-editor.org/info/rfc2119>. rfc2119>.
[RFC5988] Nottingham, M., "Web Linking", RFC 5988, [RFC5988] Nottingham, M., "Web Linking", RFC 5988, DOI 10.17487/
DOI 10.17487/RFC5988, October 2010, RFC5988, October 2010, <https://www.rfc-editor.org/info/
<http://www.rfc-editor.org/info/rfc5988>. 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,
<http://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, Application Protocol (CoAP)", RFC 7252, DOI 10.17487/
DOI 10.17487/RFC7252, June 2014, RFC7252, June 2014, <https://www.rfc-editor.org/info/
<http://www.rfc-editor.org/info/rfc7252>. rfc7252>.
[RFC7641] Hartke, K., "Observing Resources in the Constrained [RFC7641] Hartke, K., "Observing Resources in the Constrained
Application Protocol (CoAP)", RFC 7641, Application Protocol (CoAP)", RFC 7641, DOI 10.17487/
DOI 10.17487/RFC7641, September 2015, RFC7641, September 2015, <https://www.rfc-editor.org/info/
<http://www.rfc-editor.org/info/rfc7641>. 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 (gth) example A.1. Greater Than (gt) example
Observed CLIENT SERVER Actual Observed CLIENT SERVER Actual
t State | | State t State | | State
____________ | | ____________ ____________ | | ____________
1 | | 1 | |
2 unknown | | 18.5 Cel 2 unknown | | 18.5 Cel
3 +----->| Header: GET 3 +----->| Header: GET
4 | GET | Token: 0x4a 4 | GET | Token: 0x4a
5 | | Uri-Path: temperature 5 | | Uri-Path: temperature
6 | | Uri-Query: gth="25" 6 | | Uri-Query: gt="25"
7 | | Observe: 0 (register) 7 | | Observe: 0 (register)
8 | | 8 | |
9 ____________ |<-----+ Header: 2.05 9 ____________ |<-----+ Header: 2.05
10 | 2.05 | Token: 0x4a 10 | 2.05 | Token: 0x4a
11 18.5 Cel | | Observe: 9 11 18.5 Cel | | Observe: 9
12 | | Payload: "18.5 Cel" 12 | | Payload: "18.5 Cel"
13 | | 13 | |
14 | | 14 | |
15 | | ____________ 15 | | ____________
16 ____________ |<-----+ Header: 2.05 16 ____________ |<-----+ Header: 2.05
17 | 2.05 | 26 Cel Token: 0x4a 17 | 2.05 | 26 Cel Token: 0x4a
18 26 Cel | | Observe: 16 18 26 Cel | | Observe: 16
29 | | Payload: "26 Cel" 29 | | Payload: "26 Cel"
20 | | 20 | |
21 | | 21 | |
Figure 2: Client Registers and Receives one Notification of the Figure 2: Client Registers and Receives one Notification of the
Current State and One of a New State when it passes through the Current State and One of a New State when it passes through the
greather than threshold of 25. greather than threshold of 25.
A.2. Greater Than (gth) and Period Max (pmax) example A.2. Greater Than (gt) and Period Max (pmax) example
Observed CLIENT SERVER Actual Observed CLIENT SERVER Actual
t State | | State t State | | State
____________ | | ____________ ____________ | | ____________
1 | | 1 | |
2 unknown | | 18.5 Cel 2 unknown | | 18.5 Cel
3 +----->| Header: GET 3 +----->| Header: GET
4 | GET | Token: 0x4a 4 | GET | Token: 0x4a
5 | | Uri-Path: temperature 5 | | Uri-Path: temperature
6 | | Uri-Query: pmax="20";gth="25" 6 | | Uri-Query: pmax="20";gt="25"
7 | | Observe: 0 (register) 7 | | Observe: 0 (register)
8 | | 8 | |
9 ____________ |<-----+ Header: 2.05 9 ____________ |<-----+ Header: 2.05
10 | 2.05 | Token: 0x4a 10 | 2.05 | Token: 0x4a
11 18.5 Cel | | Observe: 9 11 18.5 Cel | | Observe: 9
12 | | Payload: "18.5 Cel" 12 | | Payload: "18.5 Cel"
13 | | 13 | |
14 | | 14 | |
15 | | 15 | |
16 | | 16 | |
skipping to change at line 740 skipping to change at page 16, line 25
Mountain View 94043 Mountain View 94043
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
Huawei
No.127 Jinye Road, Huawei Base, High-Tech Development District
Xi'an, Shaanxi Province
China
Email: jintao.zhu@huawei.com
Bilhanan Silverajan (editor)
Tampere University of Technology
Korkeakoulunkatu 10
Tampere FI-33720
Finland
Email: bilhanan.silverajan@tut.fi
 End of changes. 49 change blocks. 
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