Exchange/SNA Manual

Exchange/SNA Components
Introduction
1–6 104700 Tandem Computers Incorporated
Exchange/SNA
Components
Exchange/SNA has the following components:
Command interpreter
Send/receive server
Line server
Trace server
Each of these components is described below.
The Command Interpreter The Exchange/SNA command interpreter provides a command-driven interface that
enables access to all the communication capabilities of Exchange/SNA. The command
interpreter is the operator interface for Exchange/SNA and corresponds to the IBM
terminal’s console keyboard, control panel, and display. The command interpreter
enables you to send data to and receive data from the host system and to control the
other Exchange/SNA components.
You start the Exchange/SNA command interpreter by using the RJECIS command.
You can then enter commands interactively, or you can execute a sequence of
commands stored in a file, which can automate repetitive tasks.
The Send/Receive Server The Exchange/SNA send/receive server is used by the Exchange/SNA command
interpreter to send and receive files. The command interpreter starts a send/receive
server for each separate send or receive operation and then stops the send/receive
server when the operation has completed. The send/receive server has no user
interface; you do not use it directly.
The Line Server The Exchange/SNA line server provides a record-oriented interface using standard
file-system procedure calls and manages the communications with the host system
over the data communications line. The Exchange/SNA subdevices are implemented
by the line server.
When the line server is started, it establishes communications with the host system
and establishes sessions between its logical units and logical units in the host system.
These sessions are maintained until the line server is stopped.
The line server is started by the Exchange/SNA command interpreter. The line server
records the accessor (user) ID of the command interpreter that started it. All command
interpreters with the same accessor ID are said to be privileged with respect to that
line server. Certain commands, such as stopping the line server, require a privileged
line server. Command interpreters that are not privileged (have a different accessor
ID) cannot perform privileged commands. All commands that require a privileged
command interpreter are noted in the command descriptions in Section 3.