FDDI stands for Fiber Distributed Data Interface. It is a set of ANSI and ISO standards for data transmission on fiber optic lines in a local area network (LAN) that can extend in range up to 200 km (124 miles). The FDDI protocol is based on the token ring protocol. In an FDDI network, data is transmitted over fiber optics in a dual ring of trees structure, which provides redundancy and improves reliability. Each ring can carry data at a speed of 100 Mbps, and the dual ring structure allows for data to be sent in one direction on one ring and in the opposite direction on the other ring, enhancing the fault tolerance of the network.

FDDI was designed to support high-speed networking applications such as digital video and real-time data processing. It was widely used in the late 1980s and 1990s for backbone network systems and as a standard for connecting major computers, especially in complex installations such as universities and large corporations. However, with the advent of faster and more cost-effective technologies such as Gigabit Ethernet, the use of FDDI has significantly declined.

Network congestion occurs when a network or a part of it is overloaded, meaning there are too many packets (units of data) being transmitted simultaneously, exceeding its handling capacity. This situation is similar to traffic congestion on roads, where the number of vehicles surpasses the road’s capacity to efficiently manage the traffic flow. In the context of data networks, this can lead to delays (increased latency), packet loss, and the degradation of network service quality. It happens in various scenarios such as when numerous users access a service simultaneously, an unexpected surge in network traffic, or when bandwidth is limited. Network congestion can be managed and mitigated through techniques like traffic shaping, congestion control algorithms, upgrading network infrastructure, and using quality of service (QoS) mechanisms to prioritize traffic.

Internet-like networks within an enterprise are commonly referred to as Intranets. An intranet is a private network that is contained within an enterprise. It is used to securely share company information and computing resources among employees. Intranets are also used to facilitate working in groups and to improve the overall internal communications efforts. They are typically built using the same technologies as the Internet, such as TCP/IP (Transmission Control Protocol/Internet Protocol) and web browsers, making them easy to use and maintain. Additionally, intranets often have connections to the public Internet, protected by firewall software to prevent unauthorized access.