Consider the packet-switching network depicted in Figure 20.14. C is the capacity of a link in frames per second. Node A presents a constant load of 0.8 frames per second destined for A’. Node B presents a load λ destined for B’. Node S has a common pool of buffers that it uses for traffic both to A’ and B’. When the buffer is full, frames are discarded, and are later retransmitted by the source user. S has a throughput capacity of 2. Plot the total throughput (i.e., the sum of A-A’ and B-B’ delivered traffic) as a function of λ. What fraction of the throughput is A-A’ traffic for λ 7 1?