Draft: draft-ietf-core-dynlink

Commentary: Thank you
For CoAP RFC7252 Dynamic linking of state updates between resources,
either on an endpoint or between endpoints, is defined with the
concept of Link Bindings.  This specification defines conditional
observation attributes that work with Link Bindings or with CoAP
Observe RFC7641.
IETF Standards for machine to machine communication in constrained
environments describe a REST protocol and a set of related
information standards that may be used to represent machine data and
machine metadata in REST interfaces.  CoRE Link-format is a standard
for doing Web Linking RFC5988 in constrained environments.
This specification introduces the concept of a Link Binding, which
defines a new link relation type to create a dynamic link between
resources over which to exchange state updates.  Specifically, a Link
Binding is a link for binding the state of 2 resources together such
that updates to one are sent over the link to the other.  CoRE Link
Format representations are used to configure, inspect, and maintain
Link Bindings.  This specification additionally defines a set of
conditional Observe Attributes for use with Link Bindings and with
the standalone CoRE Observe RFC7641 method.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this specification are to be interpreted as described
in RFC2119.
For CoAP (RFC7252), Dynamic linking of state updates between
resources, either on an endpoint or between endpoints, is defined
with the concept of Link Bindings.  This specification defines
conditional observation attributes that work with Link Bindings or
with CoAP Observe (RFC7641).
IETF Standards for machine to machine communication in constrained
environments describe a REST protocol RFC7252 and a set of related
information standards that may be used to represent machine data and
machine metadata in REST interfaces.  CoRE Link-format RFC6690 is a
standard for doing Web Linking RFC8288 in constrained environments.
This specification introduces the concept of a Link Binding, which
defines a new link relation type to create a dynamic link between
resources over which to exchange state updates.  Specifically, a Link
Binding is a link for binding the state of two resources together
such that updates to one are sent over the link to the other.  CoRE
Link Format representations are used to configure, inspect, and
maintain Link Bindings.  This specification additionally defines a
set of conditional Observe Attributes for use with Link Bindings and
with the standalone CoRE Observe RFC7641 method.
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
BCP 14 RFC2119 RFC8174 when, and only when, they appear in all
capitals, as shown here.
In a M2M RESTful environment, endpoints may directly exchange the
content of their resources to operate the distributed system.  For
example, a light switch may supply on-off control information that
may be sent directly to a light resource for on-off control.
Beforehand, a configuration phase is necessary to determine how the
resources of the different endpoints are related to each other.  This
can be done either automatically using discovery mechanisms or by
means of human intervention and a so-called commissioning tool.  In
this specification the abstract relationship between two resources is
called a link Binding.  The configuration phase necessitates the
exchange of binding information so a format recognized by all CoRE
endpoints is essential.  This specification defines a format based on
the CoRE Link-Format to represent binding information along with the
rules to define a binding method which is a specialized relationship
between two resources.  The purpose of a binding is to synchronize
the content between a source resource and a destination resource.
The destination resource MAY be a group resource if the authority
component of the destination URI contains a group address (either a
multicast address or a name that resolves to a multicast address).
Since a binding is unidirectional, the binding entry defining a
relationship is present only on one endpoint.  The binding entry may
be located either on the source or the destination endpoint depending
on the binding method.
In a M2M RESTful environment, endpoints may directly exchange the
content of their resources to operate the distributed system.  For
example, a light switch may supply on-off control information that
may be sent directly to a light resource for on-off control.
Beforehand, a configuration phase is necessary to determine how the
resources of the different endpoints are related to each other.  This
can be done either automatically using discovery mechanisms or by
means of human intervention and a so-called commissioning tool.  In
this specification such an abstract relationship between two
resources is defined, called a link Binding.  The configuration phase
necessitates the exchange of binding information so a format
recognized by all CoRE endpoints is essential.  This specification
defines a format based on the CoRE Link-Format to represent binding
information along with the rules to define a binding method which is
a specialized relationship between two resources.  The purpose of
such a binding is to synchronize the content between a source
resource and a destination resource.  The destination resource MAY be
a group resource if the authority component of the destination URI
contains a group address (either a multicast address or a name that
resolves to a multicast address).  Since a binding is unidirectional,
the binding entry defining a relationship is present only on one
endpoint.  The binding entry may be located either on the source or
the destination endpoint depending on the binding method.
This specification registers the new "boundto" link relation type as
per RFC5988.
This specification registers the new "boundto" link relation type as
per RFC8288.