terms.adoc

Definition of Terms

Table of Contents

• General Terms
• uProtocol Terms

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General Terms

Table 1. General Terms

Term	Definition
MQTT	Lightweight publish/subscribe messaging transport
URI	Uniform Resource Identifier per RFC3986
OAuth 2.0	The industry-standard protocol for authorization.
hostname	A label that is assigned to a device connected to a computer network and that is used to identify the device in various forms of electronic communication
Domain Name	Identification string that defines a realm of administrative autonomy, authority or control within the Internet. Domain names are used in various networking contexts and for application-specific naming and addressing purposes. In general, a domain name identifies a network domain
Domain Name System (DNS)	The is the hierarchical and decentralized naming system used to identify computers, services, and other resources reachable through the Internet or other Internet Protocol (IP) networks
FQDN	Fully qualified domain name
Entity-Control-Boundary Pattern (ECB)	An architectural pattern used in use-case driven object-oriented software design that structures the classes composing a software according to their responsibilities in the use-case realization Object Description Entity Long-lived information relevant for the stakeholders (i.e. mostly derived from domain objects, usually persistent) Boundary Encapsulates interaction with external controllers (users or external systems) Controller Ensures the processing required for the execution of a use-case and its business logic, and coordinates, sequences controls other objects involved in the use-case Actor Represents an object interacting with the system. Objects, or actors, represent various roles, such as users or external systems
Protocol	A set of rules governing the exchange or transmission of data between software components
Routing	Routing is the process of path selection in any network
Packet	A block of data transmitted across a network
Binding	Creating a connection between two software entities for a specified amount of time to allow data to be sent and/or received
Communication Protocol	Is a set of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchronization of communication and possible error recovery methods. Protocols may be implemented by hardware, software, or a combination of both.
Application Protocol	An application layer protocol defines how processes (clients and servers), running on same or different end systems, pass messages to each other. In particular, an application layer protocol defines: The types of messages, e.g., request messages and response messages. The syntax of the various message types, i.e., the fields in the message and how the fields are delineated. The semantics of the fields, i.e., the meaning of the information that the field is supposed to contain; Rules for determining when and how a process sends messages and responds to messages.
Transport Protocol	A specification for providing transparent transfer of data from point-2-point, providing reliable data transfer services to the upper layers.
Network Socket	A software structure within a network node of a computer network that serves as an endpoint for sending and receiving data across the network. The structure and properties of a socket are defined by an application programming interface (API) for the networking architecture. Sockets are created only during the lifetime of a process of an application running in the node. socket is also used for the software endpoint of node-internal inter-process communication (IPC), which often uses the same API as a network socket.
CloudEvent (CE)	A specifications for describing event data in a common way
QoS	Quality of service is the description or measurement of the overall performance of a service, such as a telephony or computer network, or a cloud computing service, particularly the performance seen by the users of the network
Business Logic (Domain Logic)	The part of the program that encodes the real-world business rules that determine how data can be created, stored, and changed. It is contrasted with the remainder of the software that might be concerned with lower-level details of managing a database or displaying the user interface, system infrastructure, or generally connecting various parts of the program.

uProtocol Terms

Table 2. uProtocol Terms

Terms	Definition
C2D	Cloud-2-Device Communication
D2C	Device-2-Cloud Communication
D2D	Device-2-Device Communication
uDevice	Independent software execution environment that will implement uProtocol and contain a collection of uEs along with dispatcher(s)
Device Proxy Router (DPR)	Proxies D2D communication when devices are unable to connect directly with each other
uDomain	Collection of uDevices using DNS nomenclature
Message	Protobuf defined data structure used for communication in the uProtocol
Property	An attribute, quality, or characteristic of a uThing that are stored in the uDiscovery database
Resources	Something that can be manipulated/controlled/exposed by a service. Resources are unique when prepended with device and service. Static Topic: Resource that is declared in the service proto in Resource enum and known at compile time (ex. door, window, etc…​) Dynamic Topic: Created at runtime and not defined in the service proto (ex. geo-fence locations)
uBus	Message bus that dispatches CEs between uEs over a common transport. It provides multicast and forwarding functionality (works like a network switch)
uStreamer	Device-2-Device event dispatcher to enable seamless communication between uEs on different devices whom might talk different transport layer protocols. Performs various additional functionality such as file transfer, event buffering and more. i.e. when events need to move form one transport to the next it flows through the streamer (can be equated to an IP router)
uDiscovery	Provides a means for uEs to discover each other, their location (address), properties, and more.
Topic	What applications subscribe to and services publish to. It is represented as a uProtocol URI containing authority, sw entity, and resource information
uApplication	A uE that performs the role of consumer
uService	A uE that performs the role of producer whos interfaces are defined with a protobuf IDL
uThing	URI addressable stuff that can be accessed by the uProtocol. Examples of uThings are devices, domains, service, and resources.
Cloud Gateway	Component that lives in the cloud that devices connect with to communicate with the Back-office domain/device
uE	Pronounced "You-We" is a piece of software that communicates to another uEs using uProtocol
uP-L1	uProtocol Transport & Session Layer
uP-L2	uProtocol Communication Layer
uP-L3	uProtocol Application Layer