Directory replication conflicts can occur when an object is modified on two servers in the same site before the change has a chance to be replicated. Microsoft Exchange Server uses the following method for handling conflicts during directory replication. When a change is received by the directory, it checks the Object-Version of the object. Usually the Object-Version is higher than the existing Object-Version of the object in the local directory, and the change is committed to the directory. If the Object-Version is lower, the change is ignored. If the Object-Version is the same, the directory compares the existing DSA-Signature of the object to the incoming DSA-Signature of the object. If the DSA-Signatures match, the change is committed to the directory again. If the DSA-Signatures are different, the directory uses the more recent change based on the When-Changed attribute of the object and applies that version of the object to the directory.