Networking

FDDI

The American National Standards Institute (ANSI) developed the Fiber Distributed Data Interface (FDDI) standard in the mid-1980s to meet the growing need for a reliable and fast networking system to accommodate distributed applications. FDDI uses a ring network design, but, unlike the traditional 802.5 standard, FDDI uses a dual ring technology for fault tolerance. Because of the dual ring design, FDDI is not susceptible to a single cable failure like the regular 802.5 IEEE standard. Figure 1.8 shows an FDDI network with a dual ring configuration.

Figure 1.8. FDDI network.


As with any of the other standards, FDDI has specific characteristics:

  • Speed FDDI transmits data at 100Mbps and higher.

  • Topology FDDI uses a dual ring topology for fault-tolerant reasons.

  • Media FDDI uses fiber-optic cable that enables data transmissions that exceed two kilometers. Additionally, it is possible to use FDDI protocols over copper wire known as the Copper Distributed Data Interface (CDDI).

  • Access method Similar to 802.5, FDDI uses a token-passing access method.

Table 1.7 summarizes each of the wired standards discussed in the previous sections.

Table 1.7. IEEE 802 Network Standards

Standard

Speed

Physical Topology

Logical Topology

Media

Access Method

802.3

10Mbps

Bus and Star

Coaxial and twisted pair

CSMA/CD

802.3u

100Mbps (Fast Ethernet)

Star

Bus

Twisted pair

CSMA/CD

802.3z

1000Mbps

Star

Bus

Twisted pair

CSMA/CD

802.3ae

10-Gigabit

Backbone connections

N/A

Fiber/Not Required

802.5

4Mbps and 16Mbps

Star

Ring

Twisted pair

Token passing

FDDI

100Mbps

Dual ring

Ring

Fiber-optic Twisted pair (CDDI).

Token passing



by BrainBellupdated
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