Siemens 5881 User Manual

Dial Backup provides a backup to the Internet through an asynchronous modem connection when the default 
WAN link service experiences interruption. The modem connection can be provided through either an internal 
V.90 modem or an external V.90 or ISDN modem connected to the MGMT Console port.

Dial Backup is intended for customers with critical applications for which continuous Internet access is vital. If 
the WAN link for those applications goes down, the router automatically switches traffic to the specified 
asynchronous modem. Once the WAN link is up and stable, the router automatically switches the modem 
traffic back to the WAN. 

Use the Dial Backup option to configure a backup connection to the Internet through an external asynchronous 
modem connected to the console port. This backup connection can be activated in the event of WAN service 
interruption. During an interruption to the WAN interface connection, the router will use the dial backup modem 
connection while waiting for WAN service to be restored. Once the WAN link is active again, Dial Backup will 
automatically switch back to the WAN service. (This feature may also be useful for a customer whose WAN 
connection is not yet installed. The router begins providing service through an asynchronous modem and then 
automatically switches to the WAN when it becomes available.)

To configure a dial backup connection:

1. Click Dial Backup on the left navigation pane of the Router Information page. This displays the Dial Backup 

page.

2. Click Enable Dial Backup. 

3. Enter the User name and Password to use for the dial up connection. This information is provided by your 

ISP. 

4. In Phone number, enter the ISP’s dial up phone number. 

5. Optionally, in Alternate Phone number, enter an alternate phone number to use in the event the first 

number is unavailable. 

6. Click Apply.