Nortel Networks 620 User Manual

Page of 222
Chapter 3
Configuration via Local Pages
E-DOC-CTC-20051017-0169 v0.1
37
Miscellaneous
Comprises the following settings:
Primary Untrusted Physical Interface:
This field shows a list of your SpeedTouch™ interfaces. You select the 
preferred Primary Untrusted Physical Interface. This interface is used as the 
primary carrier for your VPN connection. In general, the primary untrusted 
interface is your DSL connection to the public Internet.
In the SpeedTouch™ the routing engine determines which interface is used for 
the VPN connection (your DSL connection to the Internet in most cases). So, 
what is the relevance to select a physical interface? 
First of all, for incoming VPN connections where your SpeedTouch™ is the 
responder in the IKE negotiations, the interface is part of the matching process 
for accepting the connection. Selecting any has the effect of removing this 
matching criterion. If you select a specific interface as Primary Untrusted 
Physical Interface
, then a 
new
 incoming VPN connection on a 
backup
 
interface
 
is not accepted.
Secondly, if your SpeedTouch™ is equipped with a backup physical interface, 
for example an ISDN backup interface, then this field determines the 
preferred
 
interface for your VPN connection. This interface is used whenever it is 
available. When this interface fails, the active VPN connections are re-routed 
via the backup interface. When the primary interface becomes available again, 
the VPN connections are re-routed to the primary interface. On the other hand, 
when you select any as the Primary Untrusted Physical Interface and this 
interface fails, the active VPN connections are also re-routed to the backup 
interface. But when the DSL connection becomes available again, the VPN 
connections are not re-routed as long as the backup connection is available.
Inactivity Timeout:
When no traffic is detected at the peer for a certain period, it is decided that the 
tunnel is not used any more, and the IKE session is terminated. All IPSec 
connections supported by the IKE session are terminated as well.
This option sets the value of the inactivity timer.
Inactivity Timeout
default value
seconds
3600