]> Cisco Systems

Brussels Belgium bbrinckm@cisco.com

Cisco Systems

170 West Tasman Drive San Jose 95134 USA rohitmo@cisco.com

Philips

Cambridge USA braeden.sanford@philips.com

Internet-Draft This memo specifies RESTful application layer interface for gateways providing operations against non-IP devices. The described interface is extensible. This memo initially describes Bluetooth Low Energy and Zigbee as they are the most commonly deployed.

Introduction Use cases in building management, healthcare, workplaces, manufacturing, logistics and hospitality have introduced low-power devices into these environments. These devices typically do not support IP-based interfaces, hence there is a need for gateway functions to allow these devices to communicate with the applications that manage them.

Gateway for non-IP Devices | Gateway |<------------>| Non-IP | | app | IP-based | | Non-IP | Device | +-------------+ Operation +---------+ Operation +--------+ ]]>

In abscence of a standard describing how applications communicate with such non-IP devices, vertically integrated infrastructure prolifilates and applications have bespoke integrations with that infrastructure for every use case. The Application interfaces are non-standard. This stunts the eco-system growth. At the same time, wireless access points have been deployed nearly everywhere, many of which have soft or separate radios that can transmit and receive different frame types, such as and . To avoid the need for parallel infrastructure and bespoke application integration, a standardized gateway function is necessary. The gateway provides at a minimum the following functions:

• authentication and authorization of application clients that will access devices
• the ability to onboard devices that are intended to be deployed within the use case
• maintenance of an inventory of onboarded devices that are intended to access and be accessed by the deployment and applications.
• interfaces that allow for bi-directional communication to non-IP devices
• one or more channels to process requests, responses, and asymmetric communciations with the non-IP radio resources (Access Points) in the system.

Combined with a provisioning interface such as , this specification supports these aspects, specifically focusing on providing bi-directional communication with non-IP devices.

Basic Architecture | SCIM | | | app |<-------------| Server | | +-----------+ Ctrl Endpt +---------+ | | | +-----------+ | +------------+ +-------+ +--+ | | Control |>...REST...|.>| |..| AP |..|D | | | & | | | Gateway | +-------+ +--+ | | Telemetry |<...MQTT...|.<| | | | Apps | | +------------+ | +-----------+ | | | Network Deployment | +-----------------------------------+ ]]>

shows us the application layer gateway (ALG), an access point (AP), and a device (D) in the enterprise environment. The role of the ALG is to provide a application gateway to non-IP devices connecting into one or more AP. Applications implementing this memo can leverage RESTful interfaces to communicate with these devices and subscribe to streaming data or broadcasts levering MQTT. The flow of operations are as follows:

1. The operator of the network deployment authorizes application(s) to perform operations on the Gateway. This happens out of band and may be accomplished by means of exchanging tokens or public keys. Authorization can be role-based:
   a. Authorize an onboarding application against a SCIM endpoint supported by the gateway.
   b. Provision and authorize applications that may control devices.
   c. Provision and authorize applications that may receive telemetry.
2. The authorized application can now provision one or more devices on the gateway leveraging SCIM.

Steps 1 and 2 are not within the scope of this specification, but are provided for context.

1. The authorized application can perform RESTful calls to the gateway in order to establish bi-directional communication to one or more devices. Optionally, set up a publish/subcribe topic to receive streaming data from a device (telemetry interface).
2. Optionally, an application can receive streaming data on a pub/sub topic configured by the control interface (telemetry interface).

Step 3 and 4 are the subject of this memo. This specification is organized into three sections:

• Basic non-IP control functions described in narrative.
• Extensibility of the interfaces.
• A specification that can be mapped to a publication/subscribe interface, such as MQTT.
• Examples of use cases leveraging both BLE and Zigbee-based devices.
• OpenAPI definitions for the control interface and Protobuf definitions for the streaming data interface

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 BCP 14 when, and only when, they appear in all capitals, as shown here.

Non-IP Control Functions This section will describe a standardized protocol-agnostic interface that allows the application to establish bi-directional communication with a non-IP device, such as a BLE or Zigbee device. The interface will be supported on a gateway as show in .

Approach In non-IP protocols such as BLE or Zigbee, a number of basic operations are defined that are similar across protocols. Examples of this are read and write data. Devices may choose to implement all of the operations or a subset. For example in BLE a device may choose to implement a binding, but could also allow connection without a binding. In this memo we have therefore defined a control interface that exposes these basic operations with a communications protocol-agnostic schema, with protocol specific extensions to transmit and receive attributes that are specific to the communications protocol supported by the device. This enables extensions to integrate new non-ip communications protocols, without the need to update the base schema.

Extensible Schema BLE | - BLE attributes | |> Zigbee - Zigbee attributes ]]>

As shown in , the control interface addresses device and group objects as IDs, hence the requirement to declare a device to the gateway before addressing a NIPC operation to the device. This is done by means of SCIM. A NIPC operation can either be performed against a device-id or a group-id. The gateway will leverage information from the SCIM object to execute a specific NIPC operation. For example, keying material found in the SCIM object may be required to connect to a device. Please refer to for more information on SCIM device objects. Apart from enabling bi-directional communication with non-ip devices, NIPC also allows an application to register pub/sub topics in order to support a programmable data streaming interface.

Common base schema As described, most operations are executed against a device or a group. Control operations refer to either of these as "Object" with an ID as an identifier. The common schema for Object is defined as follows: Definition of an Object

Attribute	Req	Type	Example
id	T	uuid	12345678-1234-5678-1234-56789abcdef4
type	T	enum	device
technology	F	enum	ble

where-

• id is the id returned in the response when registering a device against a SCIM server.
• type is either "group" or "device".
• technology is the radio technology extension(s) supported by the device, in this memo either "ble" or "zigbee".

Protocol extensions An object can support one or more communications protocols. These attributes must be described in a protocol object, for example a "ble" or a "zigbee" object. Protocol extensions

Attribute	Req	Type	Example
ble	T	object	an object with BLE-specific attributes
zigbee	T	object	an object with Zigbee-specific attributes

where-

• "ble" is an object containing attributes that are specific to the BLE protocol.
• "zigbee" is an object containing attributes that are specific to the Zigbee protocol.
• Other protocol extensions can be added

Response As most operations have a common base schema, so do responses. As mandatory, a status is returned, optionally also device id and request id. Success response: Success response

Attribute	Req	Type	Example
status	T	enum	SUCCESS
id	F	uuid	12345678-1234-5678-1234-56789abcdef4
requestID	F	uuid	abcd0987-1234-5678-1234-56789abcdef4

Failure response: Failure response

Attribute	Req	Type	Example
status	T	enum	SUCCESS
errorCode	T	int	12
reason	T	string	"Not Found"
requestID	F	uuid	abcd0987-1234-5678-1234-56789abcdef4

where-

• status is the status of the request, either "SUCCESS" or "FAILURE". In case of failure an error code and reason are added
• id is the id the operation was executed against, found in the request
• requestID is a correlation ID that can be used for end-to-end tracing.
• errorCode is a numerical value representing the error
• reason is a human readable explanation of why the error occurred

Categories of operations supported The common operations are categorized in common categories that describe high level sets of functionalities. Each of the NIPC operations belong to a category. The categories are:

• /connectivity: Allows an application to establish connectivity with a device (if so required by the technology)
• /data: Allows applications to exchange data with a device
• /registrations: Allows an application to make registrations in the network, for example to register a pub/sub topic
• /extensions: This is a category of operations that leverage basic connectivity, data or registration operations, but are optimized for application usage, allowing applications to perform functions with a reduced number of round-trips. An example of this is the the bulk operation, allowing to send multiple operations is one operation. This category also allows for further extensions based on the basic operations.

Connecting to the Non-IP Control Interface NIPC makes use of RESTful HTTP. The connection endpoint is provided out of band, most likely through the SCIM devices model extension, in which an authorized application can be registered for a SCIM object. Similarly authentication of the interface can be specified using that SCIM interface. It may be based on a device certificate or an authorization token.

Connectivity /connectivity Connectivity elements are elements that allow operations that establish or tear down associations & connectivity with devices. They also allow discovery of services that can be accessed during the connection.

Binding /connectivity/binding The binding element allows an application to request a binding or association to a device. Operations:

• Create binding: POST
• Return active bindings: GET
• Delete binding: DELETE

Create a Binding Method: POST /connectivity/binding Description: Creates a binding with a device Parameters: None Request Body: an Object as defined in Response: See for success, and for failed responses.

Return active bindings Method: GET /connectivity/binding Description: Returns one or more bindings, based on ids provided in parameters (none = return all) Parameters: One of following options: - None: return all bindings this application made - single id: return binding for this id - comma separated ids: return bindings for multiple ids Response: An Array of bindings with contents as shown in below or for failed responses. Binding response

Attribute	Req	Type	Example
status	T	enum	SUCCESS
requestID	F	uuid	abcd0987-1234-5678-1234-56789abcdef4
bindings	T	array	Array of BLE or Zigbee ids

Delete a binding Method: DELETE /connectivity/binding Description: Delete one or more bindings, based on ids provided in parameters Parameters: One of following options: - None: delete all bindings this application made - single id: delete binding for this id - comma separated ids: delete bindings for multiple ids Response: See for success, and for failed responses.

Binding by id /connectivity/binding//id/{id} The binding by id element allows an application to request a binding or association to a device by id, which provides a simpler interface than standard binding element, but pertains to a single device only. Operations:

• Create binding by id: POST
• Return active binding by id: GET
• Delete binding by id: DELETE

Create a Binding by id Method: POST /connectivity/binding/id/{id} Description: Creates a binding by id Parameters: id Response: See for success, and for failed responses.

Return active binding by id Method: GET /connectivity/binding//id/{id} Description: Returns a binding by id Parameters: id Response: See for success, and for failed responses.

Delete binding by id Method: DELETE /connectivity/binding/id/{id} Description: Delete a binding by id Parameters: id Response: See for success, and for failed responses.

Connection /connectivity/connection The connection element allows an application to request to connect to a device. Operations:

• Connect to a device: POST
• Return active connections: GET
• Disconnect a device: DELETE

Connect to a device Method: POST /connectivity/connection Description: Connect to a device Parameters: None Request Body: - an Object, as defined in - optionally a set of services to be discovered. These are supplied in protocol-specific extensions, as defined in . In the case of BLE, service discovery is performed when connecting to a device. Optionally, service discovery may be limited to services defined in the "ble" protocol extension. The services to be discovered can be added in an array, as well as optional caching parameters. Please see table below for a definition of the content of the BLE protocol extension for limited service discovery Service Discovery

Attribute	Req	Type	Example
services	T	array	Array of serviceIDs to be discovered
cached	F	boolean	no
cacheIdlePurge	F	int	3600
autoUpdate	F	boolean	yes

where-

• "services" is an array of services defined by their serviceIDs.
• "cached" refers to whether the services need to be cached for subsequent connects, in order not to perform service discovery on each request.
• "cacheIdlepurge" defines how long the cache should be maintained before purging
• some devices support notifications on changes in services, "autoUpdate" allows the network to update services based on notification (on by default)

Response: Success responses include standard success response attributes as defined in and also include cwan array of supported services. This array of supported services in turn contains an array of charateristics, which in turn contains an array of descriptors, as shown . For a description of the attributes found in this array, please refer to below. Please refer to for failed responses.

Services characteristics - charactericID - flags | |> Descriptors - descriptorID ]]>

Attributes in the array of services: Service Discovery Response Attributes

Attribute	Req	Type	Example
serviceID	F	uuid	abcd0987-1234-5678-1234-56789abcdef4
characteristicID	F	uuid	abcd0987-1234-5678-1234-56789abcdef4
flags	F	enum	write
descriptorID	F	uuid	abcd0987-1234-5678-1234-56789abcdef4

Return active connections Method: GET /connectivity/connection Description: Returns one or more active connections, based on ids provided in parameters (none = return all). Parameters: One of following options: - None: return all active connections for this application - single id: return connection status for this id - comma separated ids: return connection status for multiple ids Response: An Array of connections with attributes as defined in or in case of a failed response, the attributes in . Connection response

Attribute	Req	Type	Example
status	T	enum	SUCCESS
requestID	F	uuid	abcd0987-1234-5678-1234-56789abcdef4
connections	T	array	Array of connections

Disconnect a device Method: DELETE /connectivity/connection Description: Disconnect one or more devices, based on ids provided in parameters Parameters: One of following options: - None: Disconnect all devices for connections this application made - single id: disconnect device with id - comma separated ids: disconnect multiple devices with ids Response: See for success, and for failed responses.

Connections by id /connectivity/connection/id/{id} The connection by id element allows an application to request a connection to a device by id, which provides a simpler interface than standard connection element, but pertains to a single device only. Operations:

• Connect device by id: POST
• Return connection state by id: GET
• Disconnect device by id: DELETE

Connect device by id Method: POST /connectivity/connection/id/{id} Description: Creates a connection by id Parameters: id Response: See for success, and for failed responses.

Return connection state by id Method: GET /connectivity/connection/id/{id} Description: Returns connection state by id Parameters: id Response: See for success, and for failed responses.

Delete connection by id Method: DELETE /connectivity/connection/id/{id} Description: Delete a binding by id Parameters: id Response: See for success, and for failed responses.

Discover services supported by a device /connectivity/services The services element allows an application to request a service discovery for a device, possibly to update a cache Operations:

• Discover services: GET

Discover services supported by a device Method: GET /connectivity/service Description: Discover services supported by a device, this updates cache in case services caching is enabled for a connection. Parameters: an Object as defined in and optionally a set of services to be discovered in case not all services should be discovered. These services need to be provided in protocol-specific extensions as defined in . The services to be discovered can be added in this extension in an array, as well as optional caching parameters, as described in . Response: A successful response will contain success attributes from with an array of supported services characteristics and descriptors, as shown in , with attributes defined in . Failure Response is the standard response as defined in

Discover services supported by a device by id /connectivity/services/id/{id} The services element allows an application to request a service discovery for a device by id, possibly to update a cache Operations:

• Discover services by id: GET

Discover services supported by a device by id Method: GET /connectivity/service/id/{id} Description: Discover services supported by a device, this updates cache in case services caching is enabled for a connection. This method does not support partial service discovery, all services are discovered. Parameters: an Object id Response: A successful response will contain success attributes from with an array of supported services, characteristics and descriptors, as shown in , with attributes defined in . Failure Response is the standard response as defined in .

Data /data Data elements are elements that allow operations to exchange data with a device. This could be reading or writing attributes or enabling streaming data.

Attribute /data/attribute The attribute element allows an application get an attribute value, write, update or delete a value. Operations:

• Write value: POST
• Update value: PUT
• Read value: GET
• Delete value: DELETE

Writing a value Method: POST /data/attribute Description: Writes a value to an attribute Parameters: None Request Body: an Object as defined in , a value to be written, as defined in below and an attribute definition in a protocol extension from . The protocol extension for BLE is defined in below. The protocol extension for Zigbee is defined in below. Value

Attribute	Req	Type	Example
value	T	array	100
forcedResponse	F	boolean	no

where-

• value is the value to be written
• forcedresponse requests a specific response behavior of the device

Contents of the BLE protocol extension defining an attribute: BLE Attribute

Attribute	Req	Type	Example
serviceID	T	uuid	abcd0987-1234-5678-1234-56789abcdef4
characteristicID	T	uuid	abcd0987-1234-5678-1234-56789abcdef4
long	F	boolean	no

where-

• serviceID defines the Service
• characteristic ID defines the service characteristic
• long is an optional attribute that allows to force a write type

Contents of the Zigbee protocol extension defining an attribute: Zigbee Attribute

	endpointID	T	int	16
	clusterID	T	int	6
	attributeID	T	int	12
	type	T	int	1

where-

• endpointID defines the Zigbee endpoint that contains a cluster of attributes
• clusterID defines the Zigbee cluster that contains the attribute
• attributeID defines the Zigbee attribute
• type defines the Zigbee attribute type

Response: A successful response will contain success attributes from with optionally the value written as shown in . Failure Response is the standard response as defined in

Updating a value Method: PUT /data/attribute Description: Updates a value to an attribute Parameters: None Request Body: an Object as defined in , a value to be written, as defined in and an attribute definition in a protocol extension from . The protocol extension for BLE is defined in . The protocol extension for Zigbee is defined in . Response: A successful response will contain success attributes from with optionally the value written as shown in . Failure Response is the standard response as defined in

Read an attribute Method: GET /data/attribute Description: Reads an attribute from a device Parameters: an Object as defined in and an attribute definition in a protocol extension from . The protocol extension for BLE is defined in . The protocol extension for Zigbee is defined in . Response: A successful response will contain success attributes from with the value read as shown in . Failure Response is the standard response as defined in

clear the value from an attribute Method: DELETE /data/attribute Description: Clear the value from an attribute of a device Parameters: an Object as defined in and an attribute definition in a protocol extension from . The protocol extension for BLE is defined in . The protocol extension for Zigbee is defined in . Response: A successful response will contain success attributes from with the optionally the value as null as shown in . Failure Response is the standard response as defined in

Subscription /data/subscription The subscription element allows an application to ask a device to start streaming data attached to a certain attribute. Operations:

• Start a subscription data stream: POST
• Update a subscription data stream value: PUT
• Get status of a subscription data stream: GET
• Stop a subscription data stream: DELETE

Starting a subscription data stream Method: POST /data/subscription Description: Start a subcription data stream pertaining to a specific attribute Parameters: None Request Body: an Object as defined in and an attribute definition in a protocol extension from . The protocol extension for BLE is defined in . The protocol extension for Zigbee is defined in . Optionally a pub/sub topic can be included in the request as defined in below. Including a topic allows the app to skip the topic registration process. Topic attributes: Topic

Attribute	Req	Type	Example
topic	F	string	"enterprise/hospital/pulse"
dataFormat	F	enum	"default"
replay	F	boolean	no
forced_ack	F	boolean	no

where-

• topic is the pub/sub topic the subscription can be consumed on
• dataFormat is the data format in which the pub/sub topic is delivered
• replay is a boolean which defines whether data should be replayed in case of application disconnection
• forced ack ignores the attribute definition and forces packet ack behavior to the device

Response: See for success, and for failed responses.

Updating a subscription data stream Method: PUT /data/subscription Description: Update parameters of a subscription data stream pertaining to a specific attribute Parameters: None Request Body: an Object as defined in and an attribute definition in a protocol extension from . The protocol extension for BLE is defined in . The protocol extension for Zigbee is defined in . Optionally a pub/sub topic can be included in the request as defined in . Response: See for success, and for failed responses.

Get status of a subscription data stream Method: GET /data/subscription Description: Gets the status of a subscription data stream, success if active, failure if not active Parameters: an Object as defined in and an attribute definition in a protocol extension from . The protocol extension for BLE is defined in . The protocol extension for Zigbee is defined in . Optionally a pub/sub topic can be included in the request as defined in . Response: See for success, and for failed responses.

stop a subscription data stream Method: DELETE /data/subscription Description: stops a subscription data stream Parameters: an Object as defined in and an attribute definition in a protocol extension from . The protocol extension for BLE is defined in . The protocol extension for Zigbee is defined in . Optionally a pub/sub topic can be included in the request as defined in . Response: See for success, and for failed responses.

Subscriptions by id /data/subscription/id/{id} The subscription by id element allows an application to operate on all subscriptions of a specific id. Operations:

• Return active subscriptions by id: GET
• Terminate all subscriptions of an id: DELETE

Return active subscriptions by id Method: GET /data/subscription/id/{id} Description: Returns connection state by id Parameters: id Response: Success response as defines in and an object called "subscriptions" which contains an Array of active subscriptions. Each of these include an object as defined in and a subscription attribute definition in a protocolextension from . The protocol extension for BLE is defined in . The protocol extension for Zigbee is defined in . Failure Response is the standard response as defined in

Stop active subscriptions by id Method: DELETE /data/subscription/id/{id} Description: Delete active subscriptions for an id Parameters: id Response: Success response as defines in and an object called "subscriptions" which contains an Array of active subscriptions. Each of these include an object as defined in and a subscription attribute definition in a protocolextension from . The protocol extension for BLE is defined in . The protocol extension for Zigbee is defined in . Failure Response is the standard response as defined in

Subscriptions by topic /data/subscription/topic/{topic} The subscription by topic element allows an application to operate on all subscriptions of a specific topic. Operations: - Return active subscriptions by topic: GET - Terminate all subscriptions active on a topic: DELETE

Return active subscriptions by topic Method: GET /data/subscription/topic/{topic} Description: Returns connection state by topic Parameters: topic Response: Success response as defines in and an object called "subscriptions" which contains an Array of active subscriptions. Each of these include an object as defined in and a subscription attribute definition in a protocolextension from . The protocol extension for BLE is defined in . The protocol extension for Zigbee is defined in . Failure Response is the standard response as defined in

Stop active subscriptions by topic Method: DELETE /data/subscription/topic/{topic} Description: Delete all active subscriptions for a topic Parameters: topic Response: Success response as defines in and an object called "subscriptions" which contains an Array of active subscriptions. Each of these include an object as defined in and a subscription attribute definition in a protocolextension from . The protocol extension for BLE is defined in . The protocol extension for Zigbee is defined in . Failure Response is the standard response as defined in

Broadcast /data/broadcast The broadcast element allows an application to broadcast a message to a specific device. Note that broadcasts can be heard by other devices on the same L2 network. Operations:

• Broadcast message: POST

Broadcasting a message Method: POST /data/broadcast Description: Broadcasts a message to a device Parameters: None Request Body: an Object as defined in along with broadcast parameters, defined below in . Defining broadcast attributes is mandatory and is done by adding an array of broadcast attributes in a protocol extension from . The protocol extension for BLE broadcasts is defined in below. Broadcast parameters: Broadcast parameters

Attribute	Req	Type	Example
cycle	T	enum	single
broadcastTime	F	int	30
broadcastInterval	F	int	5

where-

• cycle determines the repetitiveness of the broadcast, and is either single or repeat
• broadcastTime is the maximum time in seconds the broadcast should run
• broadcastInterval is the time between broadcasts in seconds

Protocol-specific extensions are supplied to identify the attributes to be broadcasted. BLE Broadcast Attribute

Attribute	Req	Type	Example
adType	T	byte	ff
adData	T	byte	4c00

where-

• adType is the BLE advertisement attribute type
• adData is the BLE advertisement attribute data

Response: See for success, and for failed responses.

Registrations /registation Registration elements are elements that do not directly execute operations on devices but register attributes on the gateway that support operations, such attributes are topics for data streaming and files to write files.

Topic registration /registration/topic The topic registration element allows an application to register a pub/ sub topic for the data interface. By activating a subscription on one or more device(s), the application can then publish streaming data to that topic. Operations:

• Register a topic: POST
• Update a topic: PUT
• Get configuration of one or more topics: GET
• Delete a topic: DELETE

Registering a topic Method: POST /registration/topic Description: Register a pub/sub topic Parameters: None Request Body: A topic, including data apps that can subscribe to the topic as defined in and protocol-specific extensions as per that describe the attributes that will be reported on the topic. In the case of BLE, these are either BLE subscription attributes as in , device connection status, or Broadcast (advertisement) data as in . For Zigbee, these are Zigbee attributes as described in . Response: See with a topic name as in below for success, and for failed responses. Topic name that was registered: Topic Name

Attribute	Req	Type	Example
topic	T	string	"enterprise/hospital/pulse"

Updating a topic Method: PUT /registration/topic Description: Update a pub/sub topic Parameters: None Request Body: A topic, including data apps that can subscribe to the topic as defined in and protocol-specific extensions as per that describe the attributes that will be reported on the topic. In the case of BLE, these are either BLE subscription attributes as in , device connection status, or Broadcast (advertisement) data as in . For Zigbee, these are Zigbee attributes as described in . Response: See with a topic name as in below for success, and for failed responses.

Get configuration of one or more topics Method: GET /registration/topic Description: Gets the configuration of one or more topics Parameters: A topic name. Multiple topics can be added by comma-separated attributes. Response: A success response as in with a "topics" object containing an array of returned topics names with attribute defined in . For failed responses see .

Delete one or more topics Method: DELETE /registration/topic Description: Delete one or more topics Parameters: A topic name. Multiple topics can be added by comma-separated attributes. Response: A success response as in with a "topics" object containing an array of returned topics names with attribute defined in . For failed responses see .

Topic registrations by id /registration/topic/id/{id} The topic registration by id element allows an application to get or delete topic registrations for a specific id. Operations:

• Return active topics by id: GET
• Delete all topics for an id: DELETE

Return active topics by id Method: GET /registration/topic/id/{id} Description: Returns active topics by id Parameters: id Response: A success response as in with a "topics" object containing an array of returned topics names with attribute defined in . For failed responses see .

Delete active topics by id Method: DELETE /registration/topic/id/{id} Description: Deletes active topics by id, will delete all topics that are associated with a specific object id. Parameters: id Response: A success response as in with a "topics" object containing an array of returned topics names with attribute defined in . For failed responses see .

Topic registrations by data app /registration/topic/data-app/{data-app} The topic registration by data-app element allows an application to get or delete topic registrations for which a specific data-application is registered. Operations:

• Return active topics by data-app: GET
• Delete all topics for an data-app: DELETE

Return active topics by data-app Method: GET /registration/topic/data-app/{data-app} Description: Returns active topics by data-app Parameters: data-app Response: A success response as in with a "topics" object containing an array of returned topics names with attribute defined in . For failed responses see .

Delete active topics by data-app Method: DELETE /registration/topic/data-app/{data-app} Description: Deletes active topics by data-app, will delete all topics the specified data app is registered for. Parameters: data-app Response: A success response as in with a "topics" object containing an array of returned topics names with attribute defined in . For failed responses see .

Topic registrations by topic name /registration/topic/{topic} The topic registration by topic element allows an application to get or delete a topic registration by topic name. Operations:

• Return active topics by topic name: GET
• Delete all topics for a topic name: DELETE

Return active topics by topic name Method: GET /registration/topic/{topic} Description: Returns active topics by topic name Parameters: topic Response: A success response as in with a topic name as defined in . For failed responses see .

Delete active topics by topic name Method: DELETE /registration/topic/{topic} Description: Deletes active topics by topic name Parameters: topic Response: A success response as in with a topic name as defined in . For failed responses see .

File registration /registration/file The file registration element allows an application to register a file. a file can be used in operations to devices (such as an attribute) Operations:

• Register a file: POST
• Update a file: PUT
• Check if a file exists: GET
• Delete a file: DELETE

Registering a file Method: POST /registration/file Description: Register a file Parameters: None Request Body: a file or URL point to a file, as described in below. File definition: File

Attribute	Req	Type	Example
filename	T	string	"firmware.dat"
file	F	binary	file
bindings	F	string	"https://domain.com/firmware.dat"

Response: See for success, and for failed responses.

Updating a file Method: PUT /registration/file Description: Update a file Parameters: None Request Body: a file or URL point to a file, as described in below. Response: See for success, and for failed responses.

check presence of a registered file Method: GET /registration/file Description: Check the presence of a specific file or get all files if no file name os present in parameters Parameters: filename Response: Success as in including a "filesnames" object with an array of file names as shown in or a Failure Response as described in . A filenames object with an Array of file names: File name

Attribute	Req	Type	Example
filename	T	string	"firmware.dat"

delete a registered file Method: DELETE /registration/file Description: Delete a registered file Parameters: filename Response: See for success, and for failed responses.

file registrations by file name /registration/file/{filename} The file registration by file name element allows an application to get or delete file registrations by file name. Operations:

• Return file registrations by file name: GET
• Delete file registrations by file name: DELETE

Return file registrations by file name Method: GET /registration/file/{filename} Description: Checks the presence of a file and returns its name Parameters: filename Response: Success as in including a file name as shown in or a Failure Response as described in .

Delete file registrations by file name Method: DELETE /registration/file/{filename} Description: Delete file registrations by file name Parameters: filename Response: See for success, and for failed responses.

NIPC Extensibility NIPC is extensible in two ways:

• Protocol extensions: Protocol extensions can extend NIPC with support for new non-IP protocols
• interface extensions: Interface extensions allow extensions that leverage compound statements of basic elements to simplify common operations for applications.

Protocol extensions As described in the NIPC interface supports protocol specific extensions that allow bi-directional communication of attributes that are specific to the protocol supported by the device. This allows for extensions to the schema to integrate new non-ip communications protocols, without the need to update the base schema.

Extended Schema BLE | - BLE attributes | |> Zigbee | - Zigbee attributes | |> Protocol extension | - Protocol extension attributes ]]>

As shown in , a protocol extension can be added by adding a new technology specific extension to the schema. This is performed by adding the new protocol to the technology enum in the base objext definition Furthermore, the protocol objects need to be extended with the new protocol as well. Protocol objects will be extended as follows: Adding Protocol extensions

Attribute	Req	Type	Example
ble	T	object	an object with BLE-specific attributes
zigbee	T	object	an object with Zigbee-specific attributes
newProtocol	T	object	an object with newProtocol-specific attr

In the new protocol object, protocol specific attributes can be added.

Interface extensions /extensions The interface extension elements are freely extendible interfaces. These elements leverage the basic NIPC defined elements and combine them in compound statements in order to streamline application operation against devices, make operations more expediant and convenient in one API call. In principle they do not add any basic functionality. In the OpenAPI model below, we have defined a few example extensions, and we will describe them here at a high level to provide some context on other possible extensions.

Write file /extension/write/file This extension make use of multiple write operations (attribute post) to write an entire file to an attribute. The interface allows the application to define the chunk size. Operations:

• Write file: POST

Read conditional file /extension/read/conditional This extension performs a read operation sequentially for a defined amount of time until a specified value is read. Operations:

• Read Conditional: POST

Bulk /extension/bulk This extension allows you to create a compound operation made out of multiple connection and data operations that are to be executed sequentially until they all succeed or there is a failure. Supported operations are:

• /extension/connection/create
• /extension/connection/delete
• /extension/attribute/read
• /extension/attribute/write
• /extension/attribute/write/file
• /extension/attribute/write/blob
• /extension/attribute/read/conditional

Operations:

• Bulk: POST

Publish/Subscribe Interface The publish/subscribe interface, or data streaming interface, is an MQTT publishing interface. Pub/sub topics can be created and managed by means of the /register/topic NIPC element. In this memo we propose the data format to be protocol buffers, as fully described in the protobuf definition.

Examples This section contains a few examples on how applications can leverage NIPC operations to communicate with BLE and Zigbee devices.

BLE Advertisement In this example, we will onboard a device, and setup an advertisement subscription topic for that device. The sequence of operations for this are:

• Onboard a device using the SCIM Interface (out of scope of this memo)
• Register a topic with the device id to subscribe to advertisements POST /register/topic
• Subscribe to the topic from the data receiver app MQTT subscribe topic

BLE Attribute Read/Write In this example, we will connect to a BLE device (BLE device does not require binding) and read and write from an attribute The sequence of operations for this are:

• Onboard a device using the SCIM Interface (out of scope of this memo)
• Connect to the BLE device POST /connectivity/connection
• Read an attribute from the BLE device GET /data/attribute
• Write to an attribute on the BLE device POST /data/attribute
• Disconnect from the BLE device DELETE /connectivity/connection

Zigbee Attribute Read/Write In this example, we will bind a zigbee device to a Zigbee mesh and read and write from an attribute The sequence of operations for this are:

• Onboard a device using the SCIM Interface (out of scope of this memo)
• Bind the Zigbee device POST /connectivity/binding
• Read an attribute from the Zigbee device GET /data/attribute
• Write to an attribute on the Zigbee device POST /data/attribute
• Disconnect from the Zigbee device DELETE /connectivity/connection

Security Considerations TBD.

IANA Considerations TBD.

References Normative References North Carolina State University North Carolina State University Cisco Systems The initial core schema for SCIM (System for Cross Identity Management) was designed for provisioning users. This memo specifies schema extensions that enables provisioning of devices, using various underlying bootstrapping systems, such as Wifi EasyConnect, RFC 8366 vouchers, and BLE passcodes. In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. The QUIC transport protocol has several features that are desirable in a transport for HTTP, such as stream multiplexing, per-stream flow control, and low-latency connection establishment. This document describes a mapping of HTTP semantics over QUIC. This document also identifies HTTP/2 features that are subsumed by QUIC and describes how HTTP/2 extensions can be ported to HTTP/3. Informative References Bluetooth SIG Connectivity Standards Alliance

OpenAPI definition The following non-normative model is provide for convenience of the implementor.

Protobuf definition The following non-normative protocol buffer definition is provide for convenience of the implementor.