Lancom Systems 821 - Manual (Page 11)

LANCOM 821 ADSL/ISDN – LANCOM 1621 ADSL/ISDN – LANCOM 1711 VPN
̈ Chapter 1: Introduction
11
EN
ISDN). Other models like LANCOM 1711 VPN are connected to the splitter
using a separate ADSL modem.
The model LANCOM 1711 VPN can also utilize other broadband con-
nections (e.g. cable modem) that offer a 10/100Base-Tx-Ethernet
connector over PPPoE, PPTP or plain Ethernet (with or without DHCP).
The models LANCOM 821 ADSL/ISDN and LANCOM 1621 ADSL/ISDN
can use this option, if the first LAN port is configured as WAN inter-
face.
ADSL- over-ISDN or ADSL-over- POTS?
ADSL can operate over modern ISDN telephone service as well as conven-
tional analog service (POTS – Plain Old Telephone Service).
There are, however, different technical specifications for the two telephone
systems. For this reason, devices in the LANCOM series are offered in two dif-
ferent versions: A version for ADSL-over-POTS and a version for ADSL-over-
ISDN.
You can determine which telephone system a device supports by looking at
the model description on the bottom of the device. The label containing the
device name also contains an additional code which stands for the telephone
system the device supports:
Code Supported telephone system
'Annex A' ADSL-over-POTS
'Annex B' ADSL-over-ISDN
Router
ADSL
modem
Internet
Splitter
Telephone
Telephone
network
Splitter
ADSL provider
Switching node
DSL access
multiplexer
Subscriber