Remote Authentication Dial-In User Service (RADIUS) is a widely deployed system operating on port 1812, to provide authentication, authorization and accounting for network access.

RS-232 is an interface for the interchange of serial binary data between two devices.

The Subscriber Identity Module (SIM) is a smart card necessary to make use of a mobile phone for communication.

The Transmission Control Protocol (TCP) is a protocol that is used for reliable data communications between computers in a packet-switched computer communication network.

The uplink is a term used in radio communications and satellite communications to denote the link from the end-user to the network or from the earth to the satellite.

The downlink is a term used in radio communications and satellite communications to denote the link from the network to the end user or from the satellite to the earth.

User Datagram Protocol (UDP) a connectionless transport-layer protocol. It provides an unreliable datagram connection between applications.

The Universal Mobile Telecommunications System (UMTS) is one of the third generation (3G) mobile telecommunications systems.

The Visited Public Mobile Network (VPMN) is the network used by a mobile subscriber while roaming outside of their Home Public Mobile Network (HPMN).

The Home Public Mobile Network (HPMN) is the network of an operator in which a mobile subscriber has a subscription.

Wide Area Network (WAN) is a telecommunications network that covers a large geographic area.

A Local Area Network (LAN) is a network that interconnects devices – like computers and printers – within a relatively small area such as schools, laboratories, university campuses or office buildings.

A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions on the Internet.

Out-of-band management (OOBM) involves the use of management interfaces for managing networked equipment.

A switch is a device in a computer network that connects other devices together.

An application program interface (API) is a set of routines, protocols, and tools for building software applications.

A digital twin is a computer program that takes real-world data about a physical object or system as inputs and produces predications or simulations of how that physical object or system will be affected by those inputs.

An embedded system is a computer system that has a dedicated purpose within a larger mechanical or electrical system.

The Unstructured Supplementary Service Data, or USSD Code service that banks and other financial service providers use to service the banking community from their platforms.