Usually two types of configuration are used for used Cisco products at the time of putting them to work. The first one is the traditional configuration for the equipments to work in the given environment. The other one is the back up configuration so that in extreme cases of power failure, overloading and such other problem, it can take the place of original configuration preventing disruption of works.

Configuration of the dial back up through the serial interface you have to specify the conditions under which the back up configuration shall be triggered. Thereafter the dial back up can be configured to the interface of the DDR. It specifies the conditions as well as the destinations for all your dial calls. Serial or the primary interface as it is called may be configured either for the DDR or for the frame relay system. It could even be configured for the X 25 over a lease line. However the task performed in each case by the back up are identical.

Steps to be taken for such configuration are –

· You have to specify the interface. Then it has to be configured accordingly to DDR, Frame Relay, or the X25, as the case may be.

· Get the required knowledge about the configuring and synchronizing serial port.

· Specify the condition of activation of the back up system.

· Configure the primary interface and also the back up interface for the DDR.

Once the configuration is over, most part of your task is accomplished and only left out item would be the Cisco repair if any.