ZXUN Supplementary Service Server (SSS), ZTE MMTel server product, is located at SIP AS of IMS network application layer, providing rich voice communication services for subscribers together with IMS network. ZXUN SSS not only provides the basic point-to-point voice and video application services of IMS network, but also offers various supplementary and value-added services such as IP Centrex, supplementary service and automatic attendant console, as well as the functions of system-class online and offline charging, inspection and disaster recovery. Besides, ZXUN SSS supplies the interfaces connecting other application servers. For example, it is integrated with the servers like voice mailbox, CRBT and MMID to provide functions of voice message, CRBT and MMID. ZXUN SSS provides SIP interface of manual attendant console, achieving the function of forwarding to manual attendant console. It also has the inbuilt MRFC function. It provides IP-SM-GW and VoLTE SCC AS function in various scenarios. It adopts the ETCA (Enhanced TCA) based MP (multi-core processor) common hardware platform, compared with server platform, which has the advantages of large capacity, high integration, high reliability and effective cost. The maximum capacity supports 20 million subscribers. Its advanced technology index and stable performance are more appropriate for operator to develop large-scale commercial networking.
It strictly complies with the specifications of 3GPP, 3GPP2 and TISPAN, and is able to interwork smoothly with the products complying with these specifications. The hardware architecture adopts ZTE new generation ETCA platform. The system is designed with multi-shelf and multi-module, achieving good scalability. The building block type expansion mode of board level, shelf level and rack level fully satisfies operator’s requirement for smooth expansion. The key parts all use master-slave hot backup working mode and are able to switch over automatically when fault occurs, ensuring the system working continuously. The system uses good traffic control technology, route policy and network processor technology to guarantee the network security and smooth flow.