Point-to-point communication is the direct communication between
trading partners using either
a direct leased line,
dial-up access via Public Switched Telephone Network (PSTN),
the international Packet Switched Public Data Networks (PDN/PSS/X.25
services),
the Integrated Services Data Network (ISDN),
or the European automobile extranet ENX (European Network eXchange).
The direct leased line is suitable for dedicated trading partner application
only. The line is available 24 hours a day,
but by nature is quite costly.
The dial-up Public Switched Telephone Network can be accessed by using
a modem and PC.
The modern transmissions are based on the advanced
networks of
transmission susch as:
X.25 provides a common international standard for the lowest
three layers of the OSI model. However the annual fee in some
countries is quite substantial and additional charges are made based
on the destination of data and the volume of data sent.
.
An alternative for smaller trading partners is to access the
X.25 network via a PAD (Package Assembler and Disassembler)
using an analogue public telephone line and a modem. The disadvantage
in this method is that, unlike a direct X.25 link where remote systems
are permanently available, the user will only be able to send and receive
calls whilst dialled to the network. The dial-up partner cannot receive
incoming calls and is therefore unsuitable for the application of JIT
techniques.
.
the European automobile extranet ENX (European Network eXchange)
and its counterpart américan ANX, to
know some more...
