LANCOM Wireless DSL – LANCOM Wireless ADSL
Chapter 1: Introduction
13
EN
technology. In the second step, we will see how this network can be optimized
by the deployment of VPN.
Conventional network infrastructure
First, let's have a look at a typical network structure that can be found in this
form or similar forms in many companies:
The corporate network is based on the internal network (LAN) in the head-
quarters. This LAN is connected to the outside world in three ways:
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A subsidiary is connected to the LAN, typically using a leased line.
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PCs dial into the central network via modem or ISDN connections (Remote
Access Service – RAS).
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The central LAN has a connection to the Internet so that its users can
access the Web, and send and receive e-mail.
All connections to the outside world are based on dedicated lines, i.e.
switched or leased lines. Dedicated lines are very reliable and secure. On the
other hand, they involve high costs. In general, the costs for dedicated lines
are dependent on the distance. Especially in the case of long-distance con-
nections, keeping an eye out of cost-effective alternatives can be worthwhile.
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Head Office
Workstation in remote
access, e.g. homework
Internet
LAN
LAN
Subsidiary
