02-08-2016, 12:53 PM
Abstract
Network Border Patrol (NBP) is a congestion avoidance mechanism. whichallows routers on the borders (or edges) of a network to perform flowclassification and maintain per-flow state but does not allow routers at thecore of the network to do so.Depending on which flowit is operating on, an edge router may be viewed as ingress or an egressrouter. An edge router operating on a flow passing into a network is called aningress router, whereas an edge router operating on a flow passing out of anetwork is called an egress router.NBP prevents congestioncollapse through a combination of per-flow rate monitoring at egress routersand per-flow rate control at ingress routers. Rate monitoring allows an egressrouter to determine how rapidly each flow's packets are leaving the network,whereas rate control allows an ingress router to police the rate at which eachflow's packets enter the network.