The network is a system that provides multiple entities with a product they need. Biological networks provide life giving essentials to a body, ecological networks keep the world running, human networks allow for physical and informative movement. The fibers of these networks are the carriers, the providers for the network to work. Do these fibers exist in a condition that is satisfactory for the network. The network fibers relate to one another by function and relative need.
Some fibers do more than others, but all are needed or become obsolete and cut off.
Many argue that once a system exists, it should be recognized for its existence even following its demise. I see the validity of this argument but one doesn't keep a t.v. that doesn't work. This is a network provider. Usage become the key factor. A network should do its job correctly without having to spend excess energy on old network providers.