Network gateways are devices or nodes that link disparate networks by translating communications from one protocol to another. They are used to connect the corporate LAN to the public Internet, connect different internal networks, such as IT and OT networks, and provide an Internet connection. Gateways are located at the edge of the network and are responsible for translating between different protocols and data formats. They also provide an interface between two applications or networks that use different protocols.
Additionally, they can be used to monitor and measure network activity, as well as provide a secure and isolated environment for communication. A gateway node can be linked to different routers or have a router that connects it to other networks or to the Internet. It is also responsible for converting information from one protocol to another and then transferring it across the web. This requires two network adapters, one connected to the local network and the other to the Internet.
The gateway is also used to provide access to devices on one network to communicate with devices on another network. This is done by assigning a default gateway, which is a hardware point that allows private IP addresses to be routed to the Internet. The gateway is usually implemented at the network layer of the Open Systems Interconnection (OSI) architecture, but it can be placed at any OSI layer. IoT devices with their own protocols, such as Bluetooth, Zigbee, and LTE-M, may require certain gateway capabilities to connect to IT networks and servers.
The gateway node can also be used in conjunction with security protocols such as firewalls, authentication functions, and network traffic filtering.