Introduction to FDDI Network

Optical Fiber Distributed Data Interface (FDDI) is one of the highest transmission rates in the current mature LAN technology. This transmission rate up to 100MB/S network technology is based on the standard is ansix3t9.5. The network has the characteristics of timing token protocol, supports a variety of topologies, and transmits media as optical fiber. Using fiber as a transport medium has several advantages:

1, a longer transmission distance, the maximum length between adjacent stations up to 2KM, the maximum distance between stations for 200KM.

2, with large bandwidth, FDDI design bandwidth is 100mb/s.

3, with the electromagnetic and radio frequency interference suppression capability, in the transmission process is not affected by electromagnetic and radio frequency noise, also does not affect its equipment.

4, optical fiber can prevent transmission during the interception of eavesdropping, but also to eliminate the radiation wave of eavesdropping, so is the most secure transmission media. FDDI, which is composed of optical fibers, has a basic structure of reverse double loops, as shown in Figure 1. One Ring is the main ring and the other ring is the standby ring. When the device fails on the main ring or the cable fails, the normal operation of FDDI can be maintained by switching from the main ring to the standby loop. This fault-tolerant capability is not in other networks. This issue will be about the basic components of FDDI, topology and operating principles, and so on.

Figure 1