Introduction to Tandem X.25 Capabilities

X25AM Connectivity
Tandem X.25 Features and Capabilities
065307 Tandem Computers Incorporated 2–13
Figure 2-4. User Application and X25AM Connectivity
022
Your Applications
Bit-synchronous Controller or
General-purpose Controller
Other
Tandem
Processes
Controllers
Expand OSI/AS
OSI/TS
SNAX/
XF
TCP/IP
I/O Process
X.25 Packet Switching Data Network
Legend
Functions you provide
Functions Tandem products provide
Pathway/
TCP
TACL X3PAD
X25AM
SysWay
Connecting Local
Asynchronous Terminals
through X3PAD
An asynchronous terminal can transmit and receive only character data; whereas, a
packet-switching network can transmit and receive only packets. As mentioned in
Section One, a hardware or software PAD places the asynchronous data from the
terminal into X.25 packets for transmission to the PSDN. The PAD also processes the
packets received from the PSDN for the terminal, removing the surrounding packet
information and transmitting the asynchronous data in a form that is compatible with
the particular terminal.
X25AM comes with its own software PAD application for your convenience. The X.3
Packet Assembler/Disassembler program (X3PAD) enables a user at an interactive
(conversation-mode) terminal connected to a Tandem NonStop system to access other
systems through a PSDN. X3PAD does not support block-mode terminals. Some
input sources that can be used to communicate through X3PAD are:
Tandem 65xx terminals
Tandem emulator terminals
Multilan terminals
X3PAD passes data between the user terminal and the network. Functions performed
by X3PAD can be controlled by commands issued from the terminal or by PAD