A large-capacity service control node architecture using multicasting access to decentralized databases in the Advanced Intelligent Network

Focusing on a distributed control service-control-node (SCP) that houses a database (DB) distributed across multiple modules, this paper proposes an a utonomous distributed SCP architecture using multicasting access to the dis tributed DB, and highlights its application areas. We assume as a basic con dition that neither the network nor the other modules in the system are awa re of the DB configuration. Based on this condition, we propose two basic m ethods: a unicast approach in which the DB management module that is select ed at random by the network routes the DB access request to the module wher e the target data resides (Method A), and a multicast method in which DB ac cess requests are broadcast to all modules (Method B). A quantitative evalu ation is made of the number of required modules and required communications performance between modules which is determined by the capacity of the mai n memory and processing capacity of the processors. Based on the results, w e conclude that Method B better exploits the advantages of module autonomou s distribution technology within the limits that the economy of inter-modul e communication overhead is not impaired. Furthermore, in the event a modul e fails in Method B, a scheme is proposed in which the defective module is cut out of the multicast group, and multicasting continues. This could be i mplemented most effectively using a separate route under hardware control t hat is independent of the on-line communications route between modules.