Lancom Systems 821 - Manual (Page 56)

LANCOM 821 ADSL/ISDN – LANCOM 1621 ADSL/ISDN – LANCOM 1711 VPN
̈ Chapter 6: Providing dial- up access
56
EN
6.1.2 Settings for TCP/IP
Each active RAS user must be assigned an IP address when using the TCP/IP
protocol.
This IP address can be permanently assigned when setting up a user. However,
it is simpler to let the LANCOM automatically assign free IP addresses to users
when they dial in. In this case you only need to specify the IP address range
that the LANCOM should use for RAS users.
During both manual and automatic IP address assignment, please ensure that
only free addresses from the address range of your local network are used. In
our example, the IP address '10.0.1.101' will be assigned to the PC when con-
necting.
This IP address makes the computer a fully-fledged member of the LAN: with
the appropriate rights, it can access all of the other devices in the LAN. The
same applies in the other direction as well: computers in the LAN will also be
able to access the remote machine.
The ISDN calling line identity (CLI)
The ISDN caller ID—also known as CLI (Calling Line Identity)—this is the telephone number
of the caller which is transmitted to the participant receiving the call. As a rule, it consists of
the country and area codes and an MSN.
The CLI is well-suited for authentication purposes for two reasons: it is very difficult to manip-
ulate, and the number is transferred free of charge via the ISDN control channel (D-channel).
10.0.1.100
(0123) 123456
User: 'SAMPLE'
(0123) 777888
ISDN adapter
Remote
workstation
IP:
10.0.1.101
LAN of the head office.
IP: 10.0.1.0
VPN or ISDN
connection