Stress Testing Websense Gateway Deployments

Hello all,

I have deployed a new websense system in my network. However before placing users onto the new gateways/brokers; I would like to perform a stress test to mimic 1000 users accessing the internet through those gateways. Is there any application that I can use that can stress/load testing which is either free or does websense have an application that can be downloaded?

Thanks.

Jit