Packgen network packet generator

Introduction

Packgen is a simple network packet generator handling diffserv markers, useful for testing network bandwidth and QoS.

It can generate several flows of data, each having its own properties such as:

name;
destination;
bandwidth;
packet size;
DSCP (Differentiated Services Code Point);
time range.

For more information about DSCP please read RFC 2474, 2475 and 3260.

See the "Installation" section to know how to install it and the "Examples" section to see how to use it. If you encounter some troubles, take a look at the "Troubleshooting" section.

This is just a 0.1 release but it is already pretty stable and can probably be used. If you find some bugs or have any questions or suggestions, don’t hesitate to send me an email to gmary[at]lunacymaze[dot]org.

Installation

To install, it’s very easy. You just have to do the following having the required privileges:

    ruby ./setup.rb

To run the unit tests you just have to do:

    cd tests
    ruby ./ts_all.rb

Examples

How to launch Packgen?

Packgen is to be used like that:

    packgen -i <input_file> [-l log_file]

Listening for flows

Here is the example file listen.yml which shows how to listen for flows on the UDP ports 5000 and 5001 and on the TCP ports 5002 and 5003:

LISTEN:

  udp:
    -
      ports: !ruby/range 5000..5001
  tcp:
    -
      ports: !ruby/range 5002..5003

You can see here that Ruby Ranges are used in order to specify that we want to listen on several consecutive ports. However, you can also simply use an Integer port number.

Sending flows

In the following example taken from the send.yml file, we describe the different flows by giving their names, their destination (host:port), the bandwidth they should use, the packet sizes, the time intervals and the DSCP values.

SEND:

  udp:
    -
      name: Voice
      host: 127.0.0.1:5000
      bandwidth: 700Kb
      packet_size: 252B
      dscp: cs6
      from..to: !ruby/range 0.0..60.0
    -
      name: Video
      host: 127.0.0.1:5001
      bandwidth: 2.8Mb
      packet_size: 750B
      dscp: cs4
      from..to: !ruby/range 10.0..60.0
  tcp:
    -
      name: Best Effort
      host: 127.0.0.1:5002
      bandwidth: 3.2Mb
      packet_size: 1KB
      from..to: !ruby/range 20.0..60.0
    -
      name: Background
      host: 127.0.0.1:5003
      bandwidth: 3.2Mb
      packet_size: 1KB
      dscp: cs1
      from..to: !ruby/range 30.0..60.0

Listening and sending at the same time

Here is the concatenation of the two previous examples (located in the listen_and_send.yml file). We add time intervals in the listening part in order to quit the program automatically when we’re finished. Note that you need to listen before sending anything!