Network users commonly must navigate a complicated maze of connectivity, all hidden from their direct control, to accomplish work on networks. In many cases the tasks of science are physically separated.
Without visibility into what is happening on the network, fixing problems can be a random walk. To better regiment the process of debugging, and to ensure a higher level of success, perfSONAR gives visibility to the nuances of each network. perfSONAR works best when there is coverage on all portions of a long path.
When all portions of the path have instrumentation, it is easier to debug, easier to operate, and easier for the base users of the network.