The Design And Implementation Of A Management System Of Internal Substation Network Based On SNMP

Since1990s, the informatization has brought a revolution to the substation.Especially, as the carrier of information, the internal network system in the substationplays an important part of the change.With the increase in the type and amount of the substation network devices, moreand more interfaces and transmission cables need to be monitored at the same time.Consequently, developing management software for this system is coming to an end.Based on SNMP (Simple Network Management Protocol), the thesis implementsthe management system of the internal network in the substation.As for the functions, this system mainly implements the multi-subnet topologydiscovery algorithm, and develops the real-time module of Host-State-Detection, andenriches the query of interfaces’ traffic.As for the technology, all subsystems make use of the synchronization mechanismto operate the data orderly, and take advantage of the shared memory and dynamiclibrary to improve the real-time performance, and utilize the stress testing to assure thestability.The system is consisted with6subsystems. The functions include networktopology discovery, traffic monitoring, trap alarm, log management, configuration,reboot and UI (User Interface) management.As the basis of the entire system, the network topology discovery subsystem iscomposed of the algorithm of topology discovery and Host-State-Detection module.Both of the algorithms in topology searching deal with the on-line devices. The list ofon-line routers is gotten by the algorithm of network topology discovery; The list ofon-line hosts and the list of on-line switches are gotten by the algorithm of link layertopology discovery. After the lists are built, the Host-State-Detection will update thedevices’ state peroidcally.The traffic monitoring subsystem can monitor the traffic in latest20minutes.Especially the pre-scan module collects all the interfaces’ traffic flow every13seconds,and the formal scan module can give the queried interface’s network flow. The cooperation of both modules can satisfy the need of the administrators, and helpadministrators to find the sources of the network congestion.The configuration and management subsystem can control the network devicesremotely. Individually, the Telnet technology helps to reboot the devices and configurethe IP address, and the Set PDU in SNMP helps to configure the system information.The trap subsystem can detect the changes of the interfaces. As the abnormalinterfaces are detected, the trap subsystem can report to the administrator timely. Thelog subsystem can record all the vital operations and equipment failures. All the dataaccumulated by log subsystem can contribute to the analysis. The UI(User Interface)subsystem is responsible for the initiation of entire system and User Interfaces’organization.The whole system has kept working well for more than one year. The properties ofreal-time and stability are evidenced by the practices. The response time to thetopology’s changes is in100milliseconds, and the memory utilization is no more than18M and averagely15M.