CSMA/CD: Minimum frame size to hear all collisions?

Question

Question from a networking class:

"In a csma/cd lan of 2 km running at 100 megabits per second, what would be the minimum frame size to hear all collisions?"

Looked all over and can't find info anywhere on how to do this. Is there a formula for this problem? Thanks for any help.

Forgery

Not a programming issue. Ask on Network Engineering but check their help centre before you post. – Obtuse

networkengineering.stackexchange.com/questions/43353/… (no answer as of yet) – Despatch

Answer 1

bandwidth delay product is the amount of data on transit. propagation delay is the amount of time it takes for the signal to propagate over network.

propagation delay=(lenght of wire/speed of signal). assuming copper wire i.e speed =2/3* speed of light

propagation delay =(2000/(2*3*10^8/3)) =10us

round trip time is the time taken for message to travel from sender to receiver and back from receiver to sender.

round trip time =2*propagation delay =20us

minimum frame size =bandwidth *delay (rtt)

frame size = bandwidth *rtt =100Mbps*20us=2000bits

Buie

Can you explain those numbers you put: propagation delay =(2000/(2*3*10^8/3)) =10us? – Insular

Propogation delay = length of wire (2000) / speed of signal which is assumed to be 2/3 times the speed of light (3*10^8) – Vitiated