Fiber Distributed Data Interface is ...

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<h2>Fiber Distributed Data Interface</h2><div class="wp-caption alignright" style="width: 310px"><a href="http://articles.techrepublic.com.com/i/tr/cms/contentPics/t01820010424eje20_01.gif" target="_blank"><img title="Fiber Distributed Data Interface" alt="Fiber Distributed Data Interface" src="http://articles.techrepublic.com.com/i/tr/cms/contentPics/t01820010424eje20_01.gif" width="300" height="270" /></a> </div><div class="wp-caption alignright" style="width: 310px"><a href="http://support.novell.com/techcenter/articles/img/dnd1998060301.gif" target="_blank"><img title="Fiber Distributed Data Interface" alt="Fiber Distributed Data Interface" src="http://support.novell.com/techcenter/articles/img/dnd1998060301.gif" width="150" height="135" /></a> </div><div class="wp-caption alignright" style="width: 310px"><a href="http://www.coffeycountyks.org/Terms/2461HTML-22.gif" target="_blank"><img title="Fiber Distributed Data Interface" alt="Fiber Distributed Data Interface" src="http://www.coffeycountyks.org/Terms/2461HTML-22.gif" width="150" height="135" /></a> </div>
<p><b>Fiber Distributed Data Interface</b> is a standard for data transmission in a local area network. It uses optical fiber as its standard underlying physical medium, although it was also later specified to use copper cable, in which case it may be called CDDI (Copper Distributed Data Interface), standardized as TP-PMD (Twisted-Pair Physical Medium-Dependent), also referred to as TP-DDI (Twisted-Pair Distributed Data Interface).</p>
<p>FDDI, as a product of American National Standards Institute X3T9.5, conforms to the Open Systems Interconnection (OSI) model of functional layering using other protocols. The standards process started in the mid 1980s. FDDI-II, a version of FDDI described in 1989, added circuit-switched service capability to the network so that it could also handle voice and video signals. Work started to connect FDDI networks to synchronous optical networking (SONET) technology.</p>
<p>Designers normally constructed FDDI rings in a network topology such as a "dual ring of trees". A small number of devices, typically infrastructure devices such as routers and concentrators rather than host computers, were "dual-attached" to both rings. Host computers then connect as single-attached devices to the routers or concentrators. The dual ring in its most degenerate form simply collapses into a single device. Typically, a computer-room contained the whole dual ring, although some implementations deployed FDDI as a metropolitan area network.</p>
<p>FDDI requires this network topology because the dual ring actually passes through each connected device and requires each such device to remain continuously operational. The standard actually allows for optical bypasses, but network engineers consider these unreliable and error-prone. Devices such as workstations and minicomputers that might not come under the control of the network managers aren't suitable for connection to the dual ring.</p>
<p>As an alternative to using a dual-attached connection, a workstation can obtain the same degree of resilience through a dual-homed connection made simultaneously to two separate devices in the same FDDI ring. One of the connections becomes active while the other one is automatically blocked. If the 1st connection fails, the backup link takes over with no perceptible delay.</p>
<p>Where PA is the preamble, SD is a start delimiter, FC is frame control, DA is the destination address, SA is the source address, PDU is the protocol data unit, FCS is the frame check Sequence (or checksum), and ED/FS are the end delimiter and frame status. The Internet Engineering Task Force defined a standard for transmission of the Internet Protocol (which would be the protocol data unit in this case) over FDDI. It was 1st proposed in June 1989 and revised in 1990. Some aspects of the protocol were compatible with the IEEE 802.2 standard for logical link control. For example, the 48-bit MAC addresses that became popular with the Ethernet family. Thus other protocols such as the Address Resolution Protocol (ARP) could be common as well.</p>


















<h3>Related Sites for Fiber Distributed Data Interface</h3>
<ul><li>Maxis <strong>Data</strong> Roaming <a href="http://2560468.r.msn.com/?ld=4v2Lc-dmzSm67EYu5UUGDNHJcbWVgFY12Ye6fRQ0Xw6B2vv2ink5ej7lk7XXb0wB3auQCMV346YzMhwNuzh7QRRlUAVBPoVASRrWJ--0kyULSJ-E-HVIet5sr0uBoSFWskp498XBolXkK3gok5urvRcKJFyNEm7rVECDscdCTOOVqMAmoXqSYu_zY6h0eEf2UffkVZY6RG6bKT_SHVyOqF9Ju70Vuv8l7L0x3PDYZWj_9-qh1nXyPFRrvJ6JzX5oGlE1yq7gGKfdy59ErJ7iqMZnXJYcRmlImT_f8n5ln_dw1qYTZvgBpEDr7dXg9_QDB5oeEOZAUJd7lslPRLwasJ2J9R5-owgq4XWcKPY5Mfx2WWhJtOoxa85IX00h5eeaiRg8RCTk9DG1luye7hEAaHEcdW_DgQJmNzPSNAFPuaABeaTWW4AY7Q--yJ04maDvnnS7YZ1xlGy7iU" target="_blank">read Fiber Distributed Data Interface</a></li>
<li><strong>Fiber Distributed Data Interface</strong> - DocWiki - Cisco Systems, Inc <a href="http://docwiki.cisco.com/wiki/Fiber_Distributed_Data_Interface" target="_blank">read Fiber Distributed Data Interface</a></li>
<li>What is FDDI (<strong>Fiber Distributed Data Interface</strong>)? - Definition from ... <a href="http://searchnetworking.techtarget.com/definition/FDDI" target="_blank">read Fiber Distributed Data Interface</a></li>
<li><strong>Fiber Distributed Data Interface</strong> â€"… <a href="http://de.wikipedia.org/wiki/Fiber_Distributed_Data_Interface" target="_blank">read Fiber Distributed Data Interface</a></li></ul>




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tags: Fiber, Distributed, Data, Interface, Fiber Distributed Data Interface, data, fddi, network, protocol

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