User`s guide
Vigor2800 Series User’s Guide 
89
Perfect Forward Secret (PFS)-The IKE Phase 1 key will be 
reused to avoid the computation complexity in phase 2. The 
default value is inactive this function. 
Local ID -In Aggressive mode, Local ID is on behalf of the IP 
address while identity authenticating with remote VPN server. 
The length of the ID is limited to 47 characters. 
Callback Function 
(for I models only) 
The callback function provides a callback service as a part of 
PPP suite only for the ISDN dial-in user. The router owner 
will be charged the connection fee by the telecom. 
Require Remote to Callback-Enable this to let the router to 
require the remote peer to callback for the connection 
afterwards. 
Provide ISDN Number to Remote-In the case that the 
remote peer requires the Vigor router to callback, the local 
ISDN number will be provided to the remote peer. Check 
here to allow the Vigor router to send the ISDN number to 
the remote router. This feature is useful for i model only. 
Allowed Dial-In Type  Determine the dial-in connection with different types. 
ISDN  Allow the remote ISDN LAN-to-LAN connection. You 
should set the User Name and Password of remote dial-in user 
below. This feature is useful for i model only. In addition, you 
can further set up Callback function below. 










