Avaya G250 Administration page 160

Configuring WAN interfaces
6. Assign a reset delay for the dialer string list using the dialer persistent delay
command. The reset delay determines the amount of time between cycles of call attempts
once all dialer strings have been attempted.
7. Enter up to five dialer strings using the dialer string command. On activation, the
dialer first attempts to connect to the number associated with dialer string 1. If the
connection attempt fails, the dialer attempts to connect to the number associated with the
next dialer string. These strings represent hunt group phone numbers configured on the
RAS server in the headquarters data center.
8. Associate the Dialer interface with its physical port using the dialer modem-interface
command. The Dialer interface must be configured to use a physical interface on the
device, to which the modem is connected. For the G250, modem dial backup is supported
only from the console port. For the G350, modem dial backup is supported on both the
console port and the USB port.
9. Configure the modem to participate in network routing using the ip unnumbered
command. An unnumbered interface uses the IP address of the interface configured in the
command. In this example, the Loopback interface has been created for the Dialer interface
to use its IP information. This IP information allows the unnumbered interface to forward
and receive IP traffic without actually assigning a static IP address to the Dialer interface.
10. Assign an access control list to the Dialer interface using the ip access-group
command. All traffic passing through the Dialer interface must meet the conditions of the
access control list associated with this access group or be rejected. In this example, the
access-group references access control list 305, which is created to block all outgoing traffic
across the Dialer interface other than the VoIP signalling traffic between the branch office
gateway and the MGC in the headquarters data center.
11. Configure the console port to support the modem using the interface console
command. The physical interface must be configured to use the attached modem. Each
modem type has different initialization requirements. The only modems supporting modem
dial backup are the MultiTech ZBA series modems. For more information on configuring the
console and USB interfaces to support modems, see
G350 for modem use
12. Assign the Dialer interface to the interface you want to back up using the
backup interface dialer command. In this example, interface dialer 1 is selected as
the backup interface to interface serial 2/1:1, the primary WAN connection to the
headquarters network. The dialer activates in the event of a failure of the serial port and all
permitted traffic transverses the Dialer interface. For more information on backing up WAN
interfaces, see
13. Configure the Loopback interface to participate in the OSPF network using the
router ospf command. In this example, a group of branch offices are assigned to OSPF
area 5. This configuration allows filtering to take place at the border points and minimizes
topology updates on the headquarters data center routers. For more information on
configuring OSPF routing, see Configuring OSPF routing in
page 348.
160 Administration for the Avaya G250 and Avaya G350 Media Gateways
on page 125.
Backup interfaces on page 146.
Chapter 9: Configuring the G250 and
Configuring OSPF on