The devices are set top boxes, modems and more. Those devices only have a single plug that plugs them into the network, technically it is all inband. It's only

The devices are set top boxes, modems and more. Those devices only have a single plug that plugs them into the network, technically it is all inband. It's only separated in that your cable modem gets a non-routable IPv6 address. It's non-routable within the internet but is a stock standard globally unique IP address. This is used for management purposes.