$1\mathrm{.}4-09$a$.$ Performance: Maximum Throughput and Capacity. Consider the network shown below. The $7$ links have transmission capacities as shownThe transmission capacities of R$\_\{1\}$ and R$\_\{6\}$ are not given. There are also three sessions $($abc$)$ from a source $($S$)$ to a destination $($D$)$ traversing these links. The R$\_\{7\}$ link is fairly shared among sessions that are bottlenecked at R$\_\{7\}$