Web Science/Part1: Foundations of the web/Ethernet/Collision detection

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Collision detection

Learning goals

  1. Understand that Ethernet is a non deterministic program
  2. Be able to reconstruct a collision detection / resolve algorithm
  3. Understand what happens if two computers send data at the same time





1 When an ethernet collision is discovered

The transmission of the current frame starts again from the beginning.
The transmission of the current frame continues at the point where it stopped when the collision was detected.
The network device waits until the other devices ask it to retransmit the data.
The network starts retransmitting data right away.

2 Who can detect a collision?

all devices on the shared medium
the recipients
the senders
the senders and recipients

3 How big is a slot time?

Maximum ethernet frame size
Minimum ethernet frame size
512 Clock cycles
none of the above

Further reading

  1. collision detection in ethernet.
  2. ALOHAnet
  3. Ethernet standard (<-- needs registration)