Tap agents are able to send and receive packets to/from an associated Network object. Assuming a network object $netobj refers to a network object, a tap agent is configured using the network method:
        set a0 [new Agent/Tap]
        $a0 network $netobj
        $a0 set fid_ 26
        $a0 set prio_ 2
        $ns connect $a0 $a1
Note that the configuration of the flow ID and priority are handled through the Agent base class. The purpose of setting the flow id field in the common header is to label packets belonging to particular flows of live data. Such packets can be differentially treated with respect to drops, reorderings, etc. The connect method instructs agent $a0 to send its live traffic to the $a1 agent via the current route through the simulated topology.

Tom Henderson 2011-11-05