Applications objects
An application object may be of two types, a traffic generator or a simulated application. Traffic generator objects generate traffic and can be of four types, namely, exponential, pareto, CBR and traffic trace.- Application/Traffic/Exponential objects
- Exponential traffic objects generate On/Off traffic. During "on" periods, packets are generated at a constant burst rate. During "off" periods, no traffic is generated. Burst times and idle times are taken from exponential distributions. Configuration parameters are:
- PacketSize_
- constant size of packets generated.
- burst_time_
- average on time for generator.
- idle_time_
- average off time for generator.
- rate_
- sending rate during on time.
- Application/Traffic/Pareto
- Application/Traffic/Pareto objects generate On/Off traffic with burst times and idle times taken from pareto distributions. Configuration parameters are:
- PacketSize_
- constant size of packets generated.
- burst_time_
- average on time for generator.
- idle_time_
- average off time for generator.
- rate_
- sending rate during on time.
- shape_
- the shape parameter used by pareto distribution.
- Application/Traffic/CBR
- CBR objects generate packets at a constant bit rate.$cbr start
Causes the source to start generating packets.
$cbr stop
Causes the source to stop generating packets.
Configuration parameters are:
- PacketSize_
- constant size of packets generated.
- rate_
- sending rate.
- interval_
- (optional) interval between packets.
- random_
- whether or not to introduce random noise in the scheduled departure times. defualt is off.
- maxpkts_
- maximum number of packets to send.
- Application/Traffic/Trace
- Application/Traffic/Trace objects are used to generate traffic from a trace file. $trace attach-tracefile tfile
Attach the Tracefile object tfile to this trace. The Tracefile object specifies the trace file from which the traffic data is to be read. Multiple Application/Traffic/Trace objects can be attached to the same Tracefile object. A random starting place within the Tracefile is chosen for each Application/Traffic/Trace object.
There are no configuration parameters for this object.
$tracefile filename trace-input
Set the filename from which the traffic trace data is to be read to trace-input.
There are no configuration parameters for this object. A trace file consists of any number of fixed length records. Each record consists of 2 32 bit fields. The first indicates the interval until the next packet is generated in microseconds. The second indicates the length of the next packet in bytes.
A simple tcl file (tg.tcl) to demonstrate different traffic sources is provided.
Some trace files:
Star Wars
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