Softswitch Core Technology

As a core device in the NGN, softswitch should be reliable and has so large capacity as to replace the PSTN. SS and SG are two important devices in the NGN network, which are in charge of processing the signals. If they broke down, it will have the terrible impact on the whole network. So device duel-homing in different place is the effective way to maintain the reliability of the network.This thesis focuses on the principles of device duel-homing and some important issues such as: how to realize the data synchronization between master SS and slave SS. How to change the work state of duel-homing SS. What is the function of duplication ownership and chain circuit between SS and TG/SG? Which kind of duel-homing ways can be applied to all the devices in NGN individually?Aimed at each problem, the author put forward several solutions. In addition, the author has made the device duel-homing test based on Alcatel NGN network. Through the comparison, the thesis gets the whole understanding of reliability and timeliness of device duel-homing solution in order to find a best method. Based on the analysis, the author brings forward a whole technical solution and provides the effective safety guarantee for NGN implementation.