LANCOM 1751 UMTS
Chapter 1: Introduction
12
EN
via the DSL interface. The device's UMTS/HSxPA interface can take its place
further along in the backup chain should the the backup router also fail.
Further information on backup solutions using VRRP are available in
the LCOS reference manual.
1.2
Location verification via ISDN or GPS
In large-scale installations with unsupervised routers, there is a risk that the
devices could be stolen and then operated at another location. If the devices
have been configured for RAS access, LAN coupling or VPN connections, a
thief could gain access from a different location to a protected network.
Location verification can prevent the misuse of a router: Each time it is swit-
ched on, the router carries out a check to make sure that it is installed at the
intended location. Only after confirming its location will the router start trans-
ferring payload data over its WAN interfaces.
Two methods of location verification are available:
Via an ISDN telephone call to itself the device can test whether it is con-
nected to the expected ISDN telephone line.
Prerequisites for successful ISDN location verification:
The device must be reachable from the public ISDN telephone net-
work.
The device needs two free B channels for the duration of the check. If
just one channel is free, e.g. one channel at a point-to-multipoint
connection with two B channels is being used for a telephone call,
then the device cannot make a call to itself via ISDN.
UMTS
NETWORK
HEADQUARTER
VPN GATEWAY
SERVER
PC
UMTS ROUTER
INTERNET
BRANCH OFFICE
ADSL
ISDN
NETWORK
VPN ROUTER
110584_LC-1751-UMTS-MANUAL-EN.book Page 12 Tuesday, February 26, 2008 5:16 PM
