Here’s an example of a good question that may be confusing due to the term “collision” having two separate meanings/contexts from Domain 3 and 4. See if you can solve it before reading the answer. This question is included in one of our free practice exams:
What is the difference between collision detection and collision avoidance?
a) Detection waits a randomly generated interval before re-transmitting, avoidance senses if the media is clear before transmitting
b) Avoidance prevents collisions by utilizing more complex math functions, whereas detection discovers the collisions as they occur
c) Detection waits a randomly generated interval before creating the digest, avoidance senses if the digest is clear before hashing
d) Avoidance prevents collisions by utilizing randomly complex signal strengths, whereas detection discovers the possible collision of frames and waits to transmit
Scroll further for the correct answer…
Remember that the question itself is focused on Domain 4, Communication and Network Security. The options are what try to confuse you by bringing in the term “collision” from Domain 3 (related to hashing). If you don’t understand the difference, you can still answer the question by focusing on what’s being asked. The bottom line is: what is the difference between CSMA/CD and CSM/CA?
Normally you might think it’s just a matter of Ethernet versus wireless, but remember the goal is to test your understanding of the Common Body of Knowledge (CBK), so it’s imperative that you grasp how things function and the various sets of terms that go along with it. Fortunately this question pulls straight from the CBK, so you should know right away that the answer is A.
If you don’t quite know the difference, but are familiar with some of the other items, you can still navigate through this question. If you recall that the phrase “collision resistant” is more often used for hashing algorithms, then you’ll know right away that options B and C are most likely not the right answer. If you know that CSMA is presented as part of the layer 1 lesson, you can eliminate option D as well, realizing that the answer must be option A through the process of elimination.
We hope this post helps. Please browse our free original practice exams to help with your preparation.