You might want to clarify a little bit your question.
What do you want to do?
Do you want / need a traffic generator? (if this is the case, i can suggest you <a href=”http://wiki.wireshark.org/Tools#Traffic_generators”>this page</a>)
As for traffic capture, there are various ways to do so.
I tend to tell you about one of the most used, that is <a href=”http://www.wireshark.org/”>Wireshark</a>.
What is your purpose?