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Switching Method

tuscanituscani Member Posts: 121
One type of frame switching uses low-latency forwarding and then switches to a
higher-latency error checking mode when an error threshold is exceeded. What is
the name of this frame switching mode?

A. store and forward
B. fragment-free
C. adaptive cut-through
D. fast-forward

Answer: C

Explanation: Adaptive cut-through is a modified form of cut-through switching in
which the switch waits for the collision window (64 bytes) to pass before forwarding.
It means that each frame will be checked into the data field to make sure no
fragmentation has occurred.

I picked... B.. Is it really C?

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    mzinzmzinz Member Posts: 328
    Yeah, it is.

    The key, or the way that they make it clear, is when the question says that the method "switches" and begins scanning a larger portion of the frames. If it receives too many errors, it begins adapting.
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    agustinchernitskyagustinchernitsky Member Posts: 299
    Fragment free waits for the first bytes (can't remember how many) of the frame to see if its fragmented.

    cut-through doesn't care about anything... :D
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    tuscanituscani Member Posts: 121
    THanks... Interesting.. I am this many months into my studies and this is the first I have heard of the adaptive version.. Just when you think you have studied it all! :)
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    agustinchernitskyagustinchernitsky Member Posts: 299
    Waittttttttt!

    I re-checked my book... since as you... I didn't like the adaptive stuff. According to my info, 3 types of switching:

    Cut-through (or FastForward according to Cisco).
    FragmentFree (Modified Cut-Through)
    Store-and-forward.

    So, your answer should be... D icon_confused.gif
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    EdTheLadEdTheLad Member Posts: 2,111 ■■■■□□□□□□
    Waittttttttt!

    I re-checked my book... since as you... I didn't like the adaptive stuff. According to my info, 3 types of switching:

    Cut-through (or FastForward according to Cisco).
    FragmentFree (Modified Cut-Through)
    Store-and-forward.

    So, your answer should be... D icon_confused.gif

    Dont make the assumption that everything you need for the exam is in your book! Multiple sources are a must.
    Networking, sometimes i love it, mostly i hate it.Its all about the $$$$
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    agustinchernitskyagustinchernitsky Member Posts: 299
    I agree... but I surely forgot about the FastForward name :)
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