In Section 
, we noted the difference between
connection-oriented and connectionless modes of communication between
processes. Connection-oriented communication requires establishment of
an association between the processes prior to exchange of information.
All OSI Application Service Elements (ASEs), whether the common type described
in this chapter or the more specialized ones of Chapters
through ,
are connection-oriented. All require that an association be established
between a process that is the initiator (client) and another that is the
responder (server).