I just added an XL4 to my network so I can now stream between my XL and XL4. While setting up the XL4, I had an interesting discussion with the Brighthouse reps helping with the Tuning Adapter/Cable Card install. When they heard I'd be streaming between the two, they insisted that I needed a filter on the coax leading to my house so that the streaming wouldn't go out to the neighborhood. I explained that my understanding was that the streaming was done via my ethernet network, but they insisted it was done through the coax.
Given that I see increased network traffic when I'm streaming, I'm pretty certain they're wrong, but thought I'd check here.