The following commands are used to setup UDP agents in simulation scripts:
$ns_ attach-agent node agent
This is a common command used to attach any <agent> to a given <node>.
$traffic-gen attach-agent agent
This a class Application/Traffic/<traffictype> method which connects the traffic generator to the given <agent>. For example, if we want to setup a CBR traffic flow for the udp agent, udp1, we given the following commands
set cbr1 [new Application/Traffic/CBR] $cbr1 attach-agent $udp1
$ns_ connect src-agent dst-agent
This command sets up an end-to-end connection between two agents (at the transport layer).
$udp set packetSize_ \
$udp set dst_addr_ \ $udp set dst_port_ \ $udp set class_ \ $udp set ttl_ \ ..... etc
The above are different parameter values that may be set as shown above for udp agents. The default values can be found in /tcl/lib/ns-default.tcl.
For a typical example of setting up an UDP agent used in a simulation, see the above section 27.1.