Basically, NIFMAN is the Symbian OS component that establishes and manages network interfaces.
NifMan allows an application to monitor network connections.NifMan uses a client/server architecture. The server defines a plug-in architecture for agents that establish such interfaces.The client interface passes application requests to monitor a connection to the NifMan server for processing. It is provided by RNif. Progress information is returned in TNifProgress(which contains progress information on a dial-up connection) objects.
When a network protocol has no route available to some destination machine or network, the system uses NifMan to start up an appropriate network interface.