[ghostly_s]

from what I've heard it's actually quite complex, using different "streaming" strategies (often not streaming from the source device at all, but instead loading the desired content directly on the chromecast device) depending on the nature of the content.

[monocasa]

IIRC there's also a per sink device signature verification scheme inherent in the protocol as the devices check in to Google's backend that makes it nearly impossible to just spin up arbitrary sink devices. Google has to have known about the device's public key before they'll talk to it, and it requires their backend fundamentally to work. That key association is probably a manufacturing step that we're not privy to.