Is there any way that a Windows Active Directory/LDAP/Domain Controller (separate from a router) could share QoS information with Windows machines that would cause the machines to throttle themselves under network load - without any specific configuration done on the Windows machines?

I am on a network where there is a Windows Domain controller that handles DNS and a Cisco router (CISCO ASA 5506) that does routing. On this network their are all types of clients: Windows, Mac, Linux, phones, tablets, etc.

A claim has been made that the Domain Controller is communicating with all the Windows machines on the network to handle QoS when the network is under load (people taking up a lot of bandwidth). No special configuration has been done to these Windows machines, as far as I know they aren't getting any Group Policy configuration from anywhere and don't have any special networking configuration.

Is it possible that the Domain Controller or any other LDAP protocol would be sharing QoS information with just the Windows machines that would cause the Windows machines to throttle themselves when the network is under load.