Introduction To Tcp/Ip - DETEWE OpenCom 100 Mounting And Commissioning

Introduction to TCP/IP

In a single LAN it is possible to use
various protocols for the transmis-
sion of data.
The connection between a worksta-
tion computer and the OpenCom
100 runs via the TCP/IP protocol,
which is used in the Internet. TCP/IP
can be used together with other pro-
tocols (e.g. NetBEUI, AppleTalk or
IPX/SPX) on the same network.
Every device participating in data
transmission using TCP/IP requires
an unambiguous IP address. An IP
address consists of four groups of
digits from 0 to 255, separated by a
full stop. The supplementary proto-
cols DHCP and PPP automatically as-
sign IP addresses to devices. Class C
networks normally use IP addresses
in which the first three numbers are
the same, and the last number is
uniquely assigned to a specific de-
vice in the LAN. In the Internet,
unique addresses assigned by a spe-
cial organisation created for this pur-
pose are used. Within a LAN, you can
use addresses which are not unique
worldwide.
TCP/IP enables the establishment of
connections via one or more inter-
mediate stations. The decision
whether to connect directly or indi-
rectly to the partner device depends
on the network mask. The network
mask for a Class C network is
255.255.255.0. If the IP address of
Configuration Examples
the partner device does not fit the
network mask, the connection is es-
tablished via the default gateway. If
a device knows several data routes
to different intermediate stations,
one speaks of a router.
The Domain Name System (DNS) re-
solves a normal language DNS name
to an IP address. The DNS is a hierar-
chically structured database, distrib-
uted worldwide. A DNS server can
supply information on the names
and IP addresses for which it is re-
sponsible. For all other information,
a DNS server contacts other DNS
servers. For the establishment of
every connection from the worksta-
tion, it is possible to give either an IP
address, or a name, which a DNS
server resolves to an IP address.
Note: For further explanations of
technical terms, please refer to the
Glossary on hte CD-ROM supplied.
Introduction to TCP/IP
41