A hub is a networking device that enables all data packets received on one of its ports to be instantly directed to all other ports, thus distributing the total bandwidth to all of the computers connected to it in the process (Erdman, 2005). A hub does not discriminate among data packets in order to direct traffic to the recipient device only so that all computers must first receive data before they can send data.

This greatly decreases bandwidth known as a half-duplex access (Erdman, 2005). On the other hand, a switch is a more efficient networking device that is gaining rapid popularity over hubs because of the way it allows a lot more control over bandwidth management and also works for both small and large networks (Spearmon, 2008). Networks are divided into Virtual LANs which does not require that all PC’s be in the same location because a switch groups PC’s according to user type.

By noting the MAC address of each PC, it sends data packets only to the corresponding PC which removes unnecessary traffic to other PC’s (Erdman, 2005). It also permits each PC to have a direct port connection which guarantees a constant amount of bandwidth supply. Further, a switch provides for the simultaneous sending and receiving of data packets which double the bandwidth of a PC also called a full duplex access (Spearmon, 2008).

A router is a gadget connected to two or more LANs, WANs or LANs and ISPs and enables the constant flow of data packets within networks and between networks and the Internet (Beal, 2005). Located at the junction between networks, also called the gateway, routers determine the quickest or the optimum path to relay data packets and do so to so to the appropriate location. Routers also communicate with one another via protocols in order to establish the best path between hosts (Beal, 2005).

Meanwhile, a channel service unit/data service unit (CSU/DSU) functions to connect a computer terminal to a digital line and is necessary at both ends of a T-1 or T-3 connection where it converts electronic computer protocol into digital telephone protocol (NationalIPResourceCenter, 2008). Specifically, the DSU provides a way of diagnosing a telephone line and protects it from electronic interference (NationalIPResourceCenter, 2008). A CSU/DSU functions in the same way as a modem only that it is digital rather than analog.