The Ethernet Data Link

"Ethernet" is the term that is casually applied to a number of very different data link implementations. You will hear people refer to "Ethernet" and they might be referring to the original DEC, Intel, and Xerox implementation of Version 1 or Version 2 Ethernet. This, in a sense, is the "true" definition of "Ethernet". When the IEEE built the 802.3 standards in 1984 the term "Ethernet" was broadly applied to them as well. Today we talk about "Fast Ethernet" and, although this technology bears many similarities to its predecessors, the engineering technology has changed dramatically.

Whatever you call it, this is a Data Link technology - responsible for delivering a frame of bits from one network interface to another - perhaps through a repeater, switch, or bridge.

Topics In This Discussion

  • Frame Formats
    The four ways that frames may be structured
  • Media Access
    Taking turns accessing the cable using the rules of Carrier Sense Multiple Access with Collision Detection (CSMA/CD)
  • Collisions
    The results of simultaneous transmissions on the media: Fragments, Runts, CRC errors
  • Propagation Delay
    The relationship between maximum cable length and minimum frame size is based on the propagation delay of the signal
  • Frame Corruption
    Troubleshooting coaxial Ethernet networks by examining the types of corruption patterns that result from specific events
  • Interframe Gap
    The 9.6 microsecond interframe gap and an understanding of its purpose
  • Signal Encoding
    Manchester Encoding for the electrical Ethernet signal

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