I am doing a network simulation which contains two part

1) SIP simulation ---I have done this with Socket

2) once the signaling is done, I need to send IP/Ethernet traffic from one end to the other end. But I do know if there are any available CLASS in Java package that can do this? or...?

But I am open to other solutions rather than Java to generate IP/Ethernet traffic..

3) is there any way to monitor the traffic amount or other statistics in Java?

Thanks so much!