Network directories, such as eDirectory, create server-to-server traffic. If this traffic crosses wide area network (WAN) links unmanaged, it can needlessly increase costs and overload slow WAN links during high-usage periods. WAN Traffic Manager lets you control server-to-server traffic (over WAN links) generated by eDirectory and control eDirectory traffic between any servers in an eDirectory tree. WTM can restrict traffic based on cost of traffic, time of day, type of eDirectory operations, or any combination of these. For example, you might restrict eDirectory traffic over a WAN link during high-usage times. This shifts high-bandwidth activities to off-hours. You might also limit replica synchronization traffic to times when rates are low to reduce costs. WAN Traffic Manager controls only periodic events initiated by eDirectory, such as replica synchronization. It does not control events initiated by administrators or users, nor does it control non-eDirectory server-to-server traffic such as time synchronization.