Introduction; How Do Adsl And Adsl 2+ Work - Lancom 1811 User Manual

LANCOM 1811 Wireless DSL – LANCOM 1821+ Wireless ADSL
Chapter 1: Introduction

1 Introduction

The models of the LANCOM Router series offer each a DSL or ADSL connector
and also an ISDN connector. The ISDN line can be used as back-up for the DSL
connection, for remote management of the router or as basis for the office
communication via LANCAPI.
In addition to their function as routers between LAN and the Internet, all
models of the LANCOM Router series operate also as base stations for wireless
networks. With the base station you link wireless PCs and notebooks to a net-
work, connect these devices to the existing wired LAN and enable also the
wireless devices to access the Internet.
1.1

How do ADSL and ADSL 2+ work?

ADSL (Asymmetric Digital Subscriber Line) is currently the most common tech-
nology for broadband Internet connections. Standard and almost ubiquitous
telephone lines (analog or DSL) are the basis for DSL data transfer to the nea-
rest telephone exchange. From here, the data is passed directly on to the
Internet over high-speed connections.
The asymmetric DSL variant ADSL was developed for applications where users
receive large amounts of data but transmit only small amounts, such as when
surfing in the WWW. ADSL subscribers can receive data at up to 8 Mbps
("downstream") and transmit at up to 800 kbps ("upstream"). ADSL providers
are able to reduce these maximum rates as they please.
To satisfy the strongly increasing demand for higher bandwidths, the stan-
dards ADSL 2 and ADSL 2+ provider higher data rates as a basis for applica-
tions such as video streaming or high-definition TV (HDTV) over the Internet.
Depending on the Internet provider, ADSL 2 devices support downstream data
rates of up to 12 Mbps, and ADSL 2+ devices support up to 24 Mbps. Hands-
10
Internet
phone line
WLAN
telephone
splitter
DSL modem LANCOM Router
LAN