The use of Local Distributors is optional. When used they become a proxy that temporarily acts as the Master Server to optimizes the distribution and management of applications, files, and directories.
Data centers can use Local Distributors to:
Minimize network traffic during deployments. The Master Server can send one copy of a component to a Local Distributor, which then replicates the component for installation on a collection of servers through the use of the Remote Agent.
Minimize firewall reconfigurations. If a firewall stands between the Master Server and a collection of servers, administrators can open the firewall just for the servers running Local Distributors, rather than for every server involved in a deployment.
Minimize the load to the Master Server during large scale deployments.