Lancom Systems 821 - Manual (Page 46)

LANCOM 821 ADSL/ISDN – LANCOM 1621 ADSL/ISDN – LANCOM 1711 VPN
̈ Chapter 5: Linking two networks
46
EN
5 Linking two networks
With the network interconnection (also known as LAN to LAN coupling) of the
LANCOM, two local networks are linked. The LAN to LAN coupling can be
realized in principle in two different ways:
Only LANCOM
1621 ADSL/ISDN
and LANCOM 1711
VPN
̈
VPN: For coupling via VPN, the connection between both LANs is estab-
lished over a specially secured connection through the public Internet. A
router with VPN support is required in both LANs.
̈
ISDN: For coupling via ISDN, a direct connection between both LANs is
established over an ISDN connection. A router with ISDN interface is
required in both LANs.
Always configure both sides
Both routers involved in the network interconnection must be configured.
Care must be taken to ensure that the configuration information provided
matches.
The following instructions will assume that LANCOM routers are being
used on both sides. A network interconnection may also be realized
with routers from other manufacturers. A mixed setup usually requires
more extensive configuration measures for both devices, however.
Please refer to the reference manual for more information in this
regard.
A setup wizard handles the configuration of the connection in the usual con-
venient manner.
Security aspects
You must, of course, protect your LAN against unauthorized access. A
LANCOM therefore offers a whole range of security mechanisms that can pro-
vide an outstanding level of protection:
̈ VPN: Network couplings via VPN transmit data by IPSec. The data are
encrypted by AES, 3-DES, Blowfish or CAST encryption algorithms.
̈
ISDN: For network couplings via ISDN, the connection password, the
checking of the ISDN number and the callback function ensure the secu-
rity of the connection.