A method and system is provided for replacing a first set of line cards with new line cards. A call-processing unit (CPU) is provided that includes a primary memory unit and a secondary memory unit. A line-card holder is populated with a second set of line cards that are interfaced with the call-processing unit. Provision is made for the data that was being processed by the original set of line cards to be processed by the second set of line cards. Connectors that were originally connected to the one or more line cards are removed and coupled to the connectors to the set of temporary line cards, which facilitate data processing while the original line cards are replaced, at which point the process is reversed.