The effectiveness of the Internet depends on the ability of the Network Administrators to implement measures that are capable of preventing congestion in the Internet. At the course of the research, it was discovered that the current Internet suffers congestion as a result of many users contending for connections and communicating. It is therefore, on the basis to address this malady that a congestion-avoidance mechanism called Network Border Patrol (NBP) is proposed and investigated. Network Border Patrol (NBP) is an Internet traffic control protocol that controls the transmission of packets at the borders of a network by patrolling the network’s borders and exchanging feedback between routers at the borders of a network, thereby ensuring that each flow’s packets do not enter the network at a rate greater than they are able to leave the network. Network Border Patrol (NBP) is to ensure that the transmitting channels or paths are not congested; packets are not delay or lost in the course of transfer. Thus, the implementation of Network Border Patrol (NBP) at the edge routers will guarantee successful packet delivery and mutual access to network shared resource. Therefore, this paper reveals the possible causes of congestion, as well as its effect on the Internet and how it can be prevented using a congestion avoidance mechanism called Network Border Patrol (NBP).