The term “uplink” is a borrowed term from the telecommunications domain, referring to a wireless connection from the ground to the orbiting satellite. In networking, this terminology refers to a LAN or Local Area Connection as it connects to the WAN or Wide Area Network, through wired or wireless connectivity.
Uplinks and Downlinks in Internet Connectivity and Telecommunications
Closely related to uplinks are “downlinks” which establish connectivity either from the satellite to the earth or from a WAN to a LAN.
To understand this scenario better, consider the way in which simple Internet downloads and uploads work. When we transfer files from the local system to the Internet server via an upload, we might be using an “uplink.” On the converse side, all downloads happen over a “downlink.”
In telecommunications, “satellite uplinks” are used to transmit signals from the ground stations to satellites in orbit. This form of transmission has its practical use in broadcasting satellite television and radio.
Sometimes, “uplinks” are also used to refer to communications paths for Internet file and data uploads in cellular and broadband services.
Uplink Port Basics for Typical Computer Networks
Uplink ports are available on appropriate networking hardware to enable plugging of network cables which allow communication with other networks. Examples of networking hardware that feature uplink ports include home routers which connect to broadband modems, which in turn enable Inter net connectivity.
Uplink connections can also be established through Ethernet ports on switches, routers, and hubs, which have a labeling system tagged by the word “WAN” or “the Internet.” Uplink ports on these devices can also be employed to increase network size by connecting the uplink port of the first device into the standard port of the second device.
However, you can neither connect two uplink ports nor connect a computer directly to an uplink port. Even the Ethernet crossover cable is not useful when attempting to connect using either of these scenarios.
Uplink Ports in Context to Modern Networking Scenarios
Over the years, networking hardware and communication protocols have evolved considerably. The latest networking system supports bi-directional connections between devices. This means that data transfer for either uploads or downloads can happen through the same network cable or wireless link. In this case, “uplink” is the term which reflects the end of the connection which initiated the data transfer.
Individual broadband routers are equipped with a dual-purpose port which is configured to serve the functions of either a standard port or an uplink port, based on which device is used to connect to it. The dual purpose port solves many issues related to the traditional method of linking and pairing a standard port and an uplink port, which would allow connections to only one of the configured ports.