A host is accessing a Web server on a remote network. Which three functions are performed by intermediary network devices during this conversation? (Choose three.)

A host is accessing a Web server on a remote network. Which three functions are performed by intermediary network devices during this conversation? (Choose three.)
applying security settings to control the flow of data
notifying other devices when errors occur
regenerating data signals
acting as a client or a server
serving as the source or destination of the messages
providing a channel over which messages travel