Introduction; How Does Dsl Work - Lancom 800+ User Manual

LANCOM 800+ – LANCOM DSL/I- 10+ – LANCOM DSL/I- 1611 Office
Chapter 1: Introduction

1 Introduction

The models LANCOM 800+, LANCOM DSL/I-10+ and LANCOM DSL/I-1611
Office are fully-featured routers that therefore also can be used in combina-
tion with the integrated firewall for providing secure Internet access to a com-
plete local network (LAN).
The VPN option, which is either integrated already or can be activated subse-
quently, enables the LANCOM DSL/I-1611 Office to act as powerful dynamic
VPN gateway for external offices or mobile users.
The LANCOM router models offer each an ISDN connector and partially an DSL
connector (LANCOM DSL/I-10+ and LANCOM DSL/I-1611 Office). The ISDN
line can be used as back-up for the DSL connection (LANCOM DSL/I-10+ and
LANCOM DSL/I-1611 Office), for remote management of the router, as basis
for the office communication via LANCAPI or for establishing dynamic VPN
connections to remote sites with dynamic IP addresses (LANCOM DSL/I-1611
Office only).
1.1

How does DSL work?

Since the late 1980s, scientists have been working on the idea of using con-
ventional telephone lines for video and multimedia applications.
High speed via standard telephone lines
Their approach was based on the use of telephone lines only for the distance
between the subscriber and the next local exchange. From the switching
center, the data is then transferred via high-speed connections to the desired
destination or target network (i.e. the Internet). This minimization of the tel-
ephone line distance used permits considerably higher transfer rates than
would be possible when relying solely on the telephone network.
ADSL connection via
LAN
telephone line
Internet
LANCOM router
Local exchange (central office)
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