The Transport layer
exchanging of data between interconnected devices
USB (Universal Serial Bus) itself is a data transfer bus that is only responsible for exchanging data and not doing anything else with it. It is just an interface or infrastructure. However, it connects to input devices, output devices, and bidirectional devices.
backbone
Physical layer devices would be a hub or a repeater to connect multiple Ethernet segments together.
They are designed to interconnect local network segments.
On a standard Ethernet network, between any two devices that communicate (such as computers), you can't have more than 4 repeaters (this includes hubs). "5-4-3" refers to a maximum of 5 segments; 4 repeaters; 3 segments with hosts on them.
Major industry product segments include aircraft engine instruments; nuclear radiation detection and monitoring instruments; commercial, geophysical, meteorological,
A guideline for 10-Mbps Ethernet networks stating that between two communicating nodes, the network cannot contain more than five network segments connected by four repeating devices, and no more than three of the segments may be populated.
the device is responsible of transfering the data from peripherial devices to its local buffer storage
Hub
The other two segments must be link segments - connecting through network connectivity devices. Adding any clients on those two links would cause additional attenuation, which is not good for the network.
the FDA