The congestion control aims to reduce and avoid congestion in network elements. If more traffic is on the network than its capacity then network element is congested. Monitoring of network traffic is the solution to detect such situations and to resolve it. In this paper, we propose generation of NetFlow packets using Cisco’s NetFlow technology, for the collection of statistics about traffic in the network. Special nodes can get the NetFlow packets generated by the Cisco’s routers, so that we can have the analysis of the contents of such packets and can detect network congestion. Juniper, 3COM, Alcatel and some other vendors provide similar features for their routers .We consider a simple system, Cisco’s feature as example which collects statistical information about network elements, determines overloaded elements and identifies flows, which congest them.