A time stamp is the value of an object that indicates the system time at some critical point in the history of the object.
A time stamp is included in a message to reduce the vulnerability of an application to replay attacks. In Web services, a replay attack occurs when an HTTP request is intercepted and the content is resent to the provider in its original form.
For the JAX-RPC run time, 5 minutes is the default message expiration time that is used for the receiver if a value is not specified in the message. If a different expiration is required for a specific client or you are unsure of the target service default value, configure a message expiration time value for the outbound time stamp.