Analog connections – using conventional telephone lines; Digital connections – using digital-grade telephone lines; switched connections – using multiple sets of links between sender and receiver to move data.
Routers can connect two or more network segments. These are intelligent network devices that store information in its routing table such as paths, hops and bottlenecks. With this info, they are able to determine the best path for data transfer. Routers operate at the OSI Network Layer.
Cables that are too long would result in signal loss. This means that data transmission and reception would be affected, because the signal degrades over length.