0

While reading CCENT/CCNA ICND1 Official Exam Certification Guide, I came across steps to how a hub creates an electrical bus:

Step 1 The network interface card (NIC) sends a frame.

Step 2 The NIC loops the sent frame onto its receive pair internally on the card.

Step 3 The hub receives the electrical signal, interpreting the signal as bits so that it can clean up and repeat the signal.

Step 4 The hub’s internal wiring repeats the signal out all other ports, but not back to the port from which the signal was received.

Step 5 The hub repeats the signal to each receive pair on all other devices.

However I fail to understand the logic behind step 2 and I am unable to find resources that explain this step. Can anyone kindly explain to me the purpose of step 2?

MykelXIII
  • 1,085
  • 1
  • 8
  • 16

1 Answers1

0

The NIC doing that loop in Half-Duplex mode (means that cannot TX / RX simultaniously) its normally an old 10baseT / 100baseT implementation. the idea is to check if the received frame received correctly, therefore it assumes that no collision was occured. since today all switches uses Full-Duplex communication, collisions cant occur anyway .

chenchuk
  • 5,324
  • 4
  • 34
  • 41
  • I read that part, but can I ask how exactly it checks if the received frame is received correctly. Is my understanding correct for the phrase "loops the sent frame onto its receive pair internally on the card" means that the data does not travel through the wires and leave the NIC? If that is the case I cannot see how the data would be corrupted due to collision since it never travels outside the NIC. – MykelXIII Sep 17 '15 at 13:35