Introduction to Tandem X.25 Capabilities

Glossary
065307 Tandem Computers Incorporated Glossary–7
NET/MASTER. One of the DSM products for network management. NET/MASTER
provides a common interface for managing both Tandem NonStop systems and IBM
systems.
network. Group of nodes connected by communications lines.
node. Point of connection in a network. Usually consists of a computer or other
peripheral device that provides a switching or terminating point in the network.
nonswitched line. Line configuration that provides a permanent path between two
stations. This path can be a privately owned cable or a dedicated path leased from a
common carrier. It is generally a leased line.
OSI. (Open Systems Interconnection).. Set of standards used for the interconnection of
heterogeneous computer systems, providing universal connectivity.
OSI/AS. OSI Application Services. Works with OSI/TS to allow applications on
Tandem systems to communicate with other systems that support OSI protocols.
OSI/MHS. OSI Mail Handling Services. Allows Tandem systems to support X.400
electronic mail messaging.
OSI/TS. OSI Transport Services. Works with OSI/AS to allow applications on Tandem
systems to communicate with other systems that support OSI protocols.
packet. Group of bits arranged in a specific format within a frame, transmitted as a
whole on a packet-switching network. The message contains both control information
(for routing) and data.
packet level. X.25 protocol description for packet formats and transmission of data
across the link between the network and the computers, terminals, or other devices.
packet size. Number of octets of user data in a data packet.
packetizing. Procedure by which a message is broken up into packets for transmission
in a packet-switching network.
packet switching. Method for transmitting information in packets in a network.
packet-switching data network (PSDN). A network providing packet-switching data
communications services. A PSDN can be either a public data network (PDN) or a
private packet-switching data network.
PAD. Packet assembler disassembler. Device that enables an asynchronous terminal
or personal computer to access a PSDN. It assembles or disassembles communications
packets. The device serves as an interface between a terminal or computer and a
packetizing network. It can be hardware or software.
PAD profile. Group of PAD parameter settings.
PDN. See public data network.
permanent virtual call (PVC). Association between two entities for packet exchange. A
call consists of data transfer and does not require call set-up and call clearing.