Based on Problem P$3$:

Consider an application that transmits data at a steady rate $($for example, the sender generates an N$-$bit unit of data every k time units, where k is small and fixed$).$ Also, when such an application starts, it will continue running for a relatively long period of time.

Suppose that a packet$-$switched network is used and the only traffic in this network comes from such applications as described above. Furthermore, assume that the sum of the application data rates is less than the capacities of each and every link. Is some form of congestion control needed?