Patent ID: 8230254

Claim:
A redundant VoIP (Voice over IP) system using an object-oriented program, wherein the system has a plurality of devices, one device is in the active state and the other devices are in the standby state, each of the devices comprising: a synchronization memory which stores one or more instances of objects which correspond to a plurality of classes, according to the order of the processing, and is not erased when a process to be carried out by the object is reproduced, wherein each instance includes: a virtual function discrimination information which is used for discriminating a function memory area located in a memory area, wherein in the function memory area a function memory corresponding to the class of the object which stores plural kinds of virtual functions generated for each process is stored; a class information which is used for discriminating a class corresponding to the object; and an object data which is used for processing the object; the function memory which is stored in a new function memory area differing from the previous reproduction of the process in the memory area, when a failure occurs in the device in the active state; an application program which reads the instance from the synchronization memory in the device in the active state and writes it to the synchronization memory of the device in the standby state; and an instance management class which, when a device newly put in the active state reproduces a process of an object by using the instance stored in the synchronization memory of this device, discriminates the class corresponding to the object by using the class information included in this instance, and sets again the virtual function discrimination information which discriminates the new function memory area to this instance.