page_title: Fast automatic restoration
section_title: FASTAR network management
hierarchical_section_title: Fast automatic restoration / FASTAR network management
caption_attribution_description: this is a diagram showing the architecture of the RNC element management system
context_page_description: Fast automatic restoration is an automated fast response system developed and deployed by American Telephone & Telegraph in 1992 for the centralized restoration of its digital transport network. FASTAR automatically reroutes circuits over a spare protection capacity when a fiber-optic cable failure is detected, hence increasing service availability and reducing the impact of the outages in the network. Similar in operation is real-time restoration, developed and deployed by MCI and used in the MCI network to minimize the effects of a fiber cut.
context_section_description: FASTAR network management is used to integrate and analyze the different data and alarms supplied by the various system elements that make up the FASTAR architecture for centralized display, and to troubleshoot and isolate problems through fault management analysis so that corrective action can be taken. The FASTAR network management cuts across three tiers.
  The first (lowest) tier consists of all the elements that constitute the FASTAR architecture, and all the interconnecting links between them.
  The second tier consists of Element Management Systems (EMSs) which are computerized operations systems (OSs) used to manage the elements that are in the first tier. The different EMSs are collectively called FASTAR Element Management Systems (FASTEMS). The two major FASTEMS are the DACS Element Management Systems (DEMS) and the RNC Element Management Systems (RNC-EMS). DEMS is designed to assist NOC with management of DACSs. In the event of a change in the status of the network due to a fiber failure, RAPID forwards this status change to DEMS, which triggers DEMS to isolate the problem. The RNC-EMS monitors the RNCs directly via the data communication network and indirectly monitors the RTE, LTE, and DASC III, and their links to the RNC, via agents residing in the RNC. It consists two components: the manager and the agent. The manager software daemon (NMd) runs on the RNC-EMS machine and is responsible for polling the RNCs. Every RNC is polled twice, once over each of the data communication networks. The agent software daemon (NAd) runs on every RNC as part of the application software. It accesses the RNC application log to respond to manager queries, and has the ability to send autonomous alarms to the manager.
  The third (highest) tier comprises only the CADS workstation and provides centralized access to the network manager via the lower two tiers.
caption: Overview of the RNC-EMS process and communications
exif: {}