In networking, a communication link is a physical connection between an end-system and a router or between routers.

There are many different types of links. For example you might be using an IEEE 802.11 (WiFi) wireless link to connect your computers at home to your broadband connection; your broadband connection will be either an Hybrid Fibre Coax (HFC) or Asymmetric Digital Subscriber Line (ADSL) connection to your Internet Service Provider (ISP). Your ISP connects to the wider Internet by one of a number of possible wide area network (WAN) links. In the University, the links used to interconnect the computers in the various PC labs will be either 100 Mbit/s or 1 Gbit/s Ethernet. You can also use WiFi to connect your laptop to the University's campus network.

If you are reading this glossary entry in a web browser running on your laptop at home, the Hypertext Transmission Protocol (HTTP) messages exchanged between your browser and the Blackboard programme running on a web server at the University will have required messages to pass through many different links and will have used several different forms of transmission media. Two important link properties are its bandwidth (which defines its transmission delay) and the end-to-end distance of the host or router connection points (which defines its propagation delay).

Glossary : A | B | C | D | E | F | G | H | I | J | K | L | M | N | P | Q | R | S | T | U | V | W | X | Y | Z