OSI/MHS Configuration and Management Manual

OSI/MHS Configuration and Management Manual—424827-003
Glossary-34
Transfer. The HP NonStop proprietary messaging system, which supports communications
among people, input/output devices, and processes.
Transfer application. A set of processes that communicate with each other and with the
Transfer subsystem and work together to perform a common task.
Transfer X400 gateway. The application that allows Transfer correspondents to exchange
packages with users on other host systems that support the international X.400
message-system standards.
transport address. See TSAP.
transport layer. Layer 4 in the OSI Reference Model. This layer provides reliable,
transparent transfer of data between end systems and ensures that the data arrives at
the correct destination.
transport selector. See TSEL.
TSAP (transport service access point). A logical location between the Transport and
Session Layers, through which transport services are made available to local users,
and through which session services are made available to remote systems.
TSEL (transport selector). An address between the Transport and Session Layers,
through which connections are established and maintained. A single TSEL can service
one or more connections simultaneously and can refer to one or more TSAPs.
TSP process. The OSI transport services process.
type. See attribute type.
UA (user agent). The functional component that represents the user in an X.400 message
handling system. A UA interacts directly with the user, prepares messages, and
submits messages for routing to their destinations. UAs also reply, retrieve, and
potentially forward messages for the user. See also RUA and LUA.
unconditional token. A token that is always present in a particular event message. See
also conditional token.
unreserved object. In the GPI, an object on the input queue that is not reserved by a client
program. A client program must reserve the object to examine or copy it.
user agent. See UA.
user database. A database in the OSI/MHS database that contains records of APPL objects.
Each APPL object corresponds to a user agent or a gateway.