Testing the broadband of an ad hoc network

I'm trying to mesure the broadband between two computers linked through PLC (and ethernet). They're not connected to the internet (I'm doing this for school and if i want the experiment to have a sense i must do it in a certain place where i can't get internet). I managed (painfully) to set up the connection between them but since they don't share data i'm stuck with an almost empty result. Can you tell me if WireShark has something like a simulator of data trafic ? And how to do this. (I've searched across the net but all i find is scams and shady little programs) (Sorry for the mistackes i'm not english)