Can anyone please help me with this question that need urgent attention please?
How the distance between stations and the number of repeaters influence the minimum frame lenght in an ethernet LAN?
Thanks for your help.
The fundemental rule of Ethernet is that when one station is transmitting - all other stations in the same collision domain must be able see the transmission and recognize the medium as busy.
If you have a very short frame size it only takes a short amount of time to transmit that fr ame. If you have a very long distance between stations and a very small frame size, it is possible for the transmitting station to finish transmitting the frame before the far end station starts to receive the frame. The far end station might decide to transmit while the other frame is still on the way down the wire. The two frames would collide somewhere near the middle causing a late collision. Furthermore, since each station finished transmitting their frames before the collision occured, there would be no way for the stations to know for sure that the frames they transmitted where corrupted, and therefore would not attempt to retransmit the frame, resulting in lost data.
The moral of the story is that there is a direct relationship between minimum frame size and distance between stations. The shorter the distance between stations, the shorter the minimum frame size can be. The longer the distance between stations, the larger the minimum frame size should be.
Since the 802.3 IEEE commitee decided that 64 bytes was a desireable minimum frame size, this resulted in a calculation that provides us with the distance and repeater limitations we have today.
Hope this helps. Please rate this post ;)