42.444 Telecommunications: A Management Perspective

1. 42.444 Telecommunications: A Management Perspective Network Management Lecture 15 (Chapters 19) Dr Gerald Grant

2. Network Management Requirements • Fault Management • Accounting Management • Configuration and Name Management • Performance Management • Security Management Dr Gerald Grant

3. Fault Management • A fault is an abnormal condition that requires management attention (or action) to repair • Fault is usually indicated by failure to operate correctly or by excessive errors • Users expect quick and reliable resolution • Users expect to be kept informed of the network status Dr Gerald Grant

4. Responding to Faults • When faults occur, it is critical to quickly: • Determine exactly where the fault is • Isolate the rest of the network from the failure so that it can continue to function without interference • Reconfigure or modify the network to minimize the effect of removing the failed component(s) • Repair or replace the failed components to restore the network to its initial state Dr Gerald Grant

5. Accounting Management • Reasons for accounting management: • Internal charge backs on network use • User(s) may be abusing access privileges and burdening the network at the expense of other users • Users may be making inefficient use of the network, and the network manager can assist in changing procedures to improve performance • The network manager is in a better position to plan for network growth if user activity is known in sufficient detail. Dr Gerald Grant

6. Configuration and Name Management • Concerned with: • initializing a network and grace-fully shutting down part or all of the network • maintaining, adding, and updating the relationships among components and the status of components themselves during network operation Dr Gerald Grant

7. Performance Management • Two functional categories: • Monitoring: tracks activities on the network • Controlling: make adjustments to improve network performance • Issues of concern to the network manager include: • What is the level of capacity utilization? • Is there excessive traffic? • Has throughput been reduced to unacceptable levels? • Are there bottlenecks? • Is response time increasing? • Network managers need performance statistics to help them plan, manage, and maintain large networks Dr Gerald Grant

8. Security Management • Concerned with • generating, distributing, and storing encryption keys • monitoring and controlling access to networks • access to all or part of the network management information • collection, storage, and examination of audit records and security logs Dr Gerald Grant

9. Network Management Systems • Collection of tools for network monitoring and control, integrated in these ways: • A single user-friendly operator interface for performing most or all network management tasks • A minimal amount of separate equipment • consists of incremental hardware and software additions implemented among existing network components Dr Gerald Grant

10. Network Management System Architecture Dr Gerald Grant

11. All nodes run the Network Management Entity (NME) software Network control host or manager runs the Network Management Application (NMA) Other nodes are considered agents Components of the NMS Dr Gerald Grant

12. Network Management Entity • Collection of software contained in each network node, devoted to the network management task • Performs the following tasks: • Collect statistics on communications and network-related activities. • Store statistics locally • Respond to commands from the network control center • Send messages to NCC when local conditions undergo a significant change Dr Gerald Grant

13. IBM Network Management Architecture and NetView • Associated with IBM’s Systems Network Architecture (SNA) • IBM wants to provide the single, unifying framework into which all other network management products feed and from which all the equipment in a user’s network can be controlled Dr Gerald Grant

14. Network Management Categories • SNA network management is composed of: • Problem management • Change management • Configuration management • Performance and accounting management Dr Gerald Grant

15. Problem Management • Problem determination • Problem diagnosis • Problem bypass and recovery • Problem resolution • Problem tracking and control Dr Gerald Grant

16. Change Management • Software change control • Microcode change control • Hardware change control Dr Gerald Grant

17. Configuration Management • Physical/logical resource identification • Resource relationship identification Dr Gerald Grant

18. Performance & Accounting Management • Response-time monitoring • Availability monitoring • Utilization monitoring • Component delay monitoring • Performance tuning • Performance tracking and control • Accounting Dr Gerald Grant

19. Control facility Provides the capability to operate the network. Hardware monitor collects notifications of failures or significant events Session monitor Collects session-related information on logical components of the network; includes measurements of data on response time, session failure Status monitor Displays status information; reactivates network resources following failures Help facilities Descriptions of fields on displays, and a systematic problem-solving facility Customization facilities: Permits a user to tailor NetView NetView Software Dr Gerald Grant

20. Technical Control • Automatic and remote testing and monitoring of the system, to reduce downtime due to the need to locate service personnel • Restoring and/or reconfiguring the system upon failure in real time • Providing network performance and functioning statistics to facilitate planning and management for high availability Dr Gerald Grant

21. Component-Level Technical Control • Line Monitors • Captures the signal between a host system and the network • Generally employed only on the network end • Large variety of equipment: digital, analog, or a combination • Protocol Analyzers • Can also simulate various network components • Can test communication protocols and codes • Typically handles up to layer 3 of the OSI architecture Dr Gerald Grant

22. Network Technical Control Systems • Integrate control devices and centralize the control of the network Dr Gerald Grant

23. Performance Monitoring • After availability, the second most important characteristic of a network is performance • Performance data must be available in sufficient detail to be able to assess the bottleneck that is causing the problem and to plan appropriate remedial action Dr Gerald Grant

24. Component-Level Monitoring • Response-time monitors • Measures, displays, and records response time of each transaction and the average response time • Hardware monitors • Events: Number of occurrences of specific events • Timing: Timing the duration of a specific signal • Software monitors • Gathers and reports statistics on hardware and systems and applications software activity Dr Gerald Grant

25. Network Monitoring Systems Dr Gerald Grant

26. Indicators Reported by Network Monitors • Service Parameters • Availability • Response Time • Accuracy and Integrity • Efficiency Parameters • Throughput • Polling • Utilization Dr Gerald Grant

27. Simple Network ManagementProtocol (SNMP) • Network Management Model • Management station • Management agent • Management information base • Network management protocol Dr Gerald Grant

28. Management Station • A set of management applications for data analysis, fault recovery, and so on • An interface by which the network manager may monitor and control the network • The capability of translating the network manager’s requirements into the actual monitoring and control of remote elements in the network • A database of information extracted from the management information bases of all the managed entities in the network Dr Gerald Grant

29. Management Agent • The management agent responds to requests for information and actions from a management station, and may asynchronously provide the management station with important but unsolicited information Dr Gerald Grant

30. Management Information Base (MIB) • A collection of access points at the agent for the management station Dr Gerald Grant

31. Role of SNMP Dr Gerald Grant

32. Protocol Specification • Transmission of a message • Receipt of a message • Variable bindings Dr Gerald Grant

33. SNMPv2 • Issued in 1993, revised in 1996 • Addressed functional deficiencies in SNMP • Accommodates decentralized network management • Improves efficiency of data transfer Dr Gerald Grant

34. SNMPv3 • Released in 1998, addressed security deficiencies in SNMP and SNMPv2 • Does not provide a complete SNMP capability; defines an overall SNMP architecture and a set of security capabilities for use with SNMPv2 • Provides three important services: authentication, privacy, and access control Dr Gerald Grant