RTSE establishes an association with a peer system on receiving RT-OPEN.request. This is accomplished by using the A-ASSOCIATE service of ACSE. Turn management is provided by invoking the token control services offered by the Presentation Layer on behalf of the Session Layer.
RTSE provides for the reliable transfer of bulk data by transforming the data into a string of octets, then breaking the string into segments and handing each segment to the Presentation Layer for delivery. Checkpoints are established between segments. Through the services of the Presentation Layer, RTSE uses the activity management services of the Session Layer to manage the transfer of the collection of segments that makes up the bulk data. Activity and minor synchronization facilities of the Session Layer support interruption and possible resumption of data transfer if the underlying network connection is lost. We will examine these services in Chapter .
RTSE is used in the X.400 Message Handling Service (MHS) and is available for use by ROSE when remote operations require reliable transfer. Because of its use in X.400, RTSE is widely available.