Lancom Systems 821 - Manual (Page 49)

LANCOM 821 ADSL/ISDN – LANCOM 1621 ADSL/ISDN – LANCOM 1711 VPN
̈ Chapter 5: Linking two networks
49
EN
̈ The password for the ISDN connection is an alternative to the use of
the ISDN caller ID. It is always used to authenticate callers that do not
send an ISDN caller ID. The exact same password must be entered on both
sides. It is used for calls in both directions.
̈
The Shared Secret is the central password for security within the VPN.
The exact same password has to be entered on both sides
̈ Data compression increases the transfer speed of the connection at no
additional cost. This is completely unlike the bundling of two ISDN- chan-
nels with MLPPP (Multi Link PPP): The transfer rate will be doubled but
there will also be additional telephone costs for two connections.
5.1.2 Settings for the TCP/IP router
In TCP/IP networks, addressing has a special significance. Please note that
two interconnected networks are logically separate from one another. Each
must therefore have its own network number (in our example, '10.0.1.x' and
'10.0.2.x'). These network numbers may not be identical.
Unlike when accessing the Internet, all of the IP addresses in the involved net-
works are visible on the remote side when coupling networks, not just those
of the router. The computer with the IP address 10.0.2.10 in the branch office
LAN sees the server 10.0.1.2 in the headquarters and can access it (assuming
it has the appropriate rights), and vice versa.
LAN of head office.
IP: 10.0.1.0,
Netmask: 255.255.255.0
Domain: 'head.company'
10.0.1.100
(0123) 123456
LAN of branch office.
IP: 10.0.2.0,
Netmask: 255.255.255.0
Domain: 'branch.company'
10.0.1.2
10.0.2.10
10.0.2.100
(0789) 654321
'server.head.company'
'pc1.branch.comany
VPN or ISDN
connection