Consider a simple network that is composed of two computers (A & B) and a router
ID: 3890084 • Letter: C
Question
Consider a simple network that is composed of two computers (A & B) and a router X in the middle. Computer A is connected to router X by a link that is 10 Mbps and has a propagation delay of 10 msec. Computer B is connected to router X by a link that is 1000 KBps and has a propagation delay of 20 msec.
a) What is the maximum rate at which computers A and B can communicate, via router X? (your answer should be in Mbps)
b) What is the physical distance between router X and computer B? Assume that the propagation speed of bits in the medium is 2 3 the speed of light in vacuum. (your answer should be in Km)
Explanation / Answer
computer A and router X bandwidth is 10Mbps and B and X is 1000Kbps(1Mbps)
a)
Average = (10+1)/2 = 5Mbps which is a maximum rate to communicate between A and B via router
b)
distance = propegation delay * velocity
velocity = 2^3 * speed of light in vaccum = 24*10^8m/s
propegation delay = 20ms for computer B = 0.02sec
therefore distance = 0.02*24*10^8
= 24000000mts
= 24000km