Consider the network scenario in the figure below. K sources are connected to th
ID: 3878075 • Letter: C
Question
Consider the network scenario in the figure below. K sources are connected to the Internet via links of capacity RS, and within the network fairly share a common link of capacity R, to K destinations. Each destination is connected to the network by a link of capacity RD. You can assume that there are no other links or source-destination pairs in the network. Suppose that source Si has an infinitely large file it wants to send to destination Di (i.e., each sources sends to a different destination).
1. Suppose that K=10, RS = 100 Mbps, RD= 54 Mbps, and R = 50 Gbps. What is the throughput between each source-destination pair? Where are the bottleneck links?
2. Suppose now that K=10, RS = 100 Mbps, RD= 1 Mbps, and R = 0.75 Gbps. What are the throughputs between each source-destination pair? Where are the bottleneck links?
3. In the scenario above, suppose we increase the capacity of the destination links to 100 Mbps. Will this increase the throughput between sources and destinations? Explain you answer.
4. Now repeat 1 above, but assume that the link connecting S1 to the network has a capacity of 1 Mbps, and that all other values are unchanged.
2 S1 Rs RD Ry RD IKExplanation / Answer
Solution 1:
The throughput will be the speed of the slowest link as that forms a bottleneck. In the given scenario three links RS, R and RD are connected in series. Hence a maximum of 100 Mb +100Mb + 54 Mb data can be travelled from source to destintion in 3 seconds hence 254/3 Mbps is the actual throughput for the given link from source to destination. The bottleneck links are RS and RD.