Tài liệu Module 1 introduction to networking management 2s

9/7/2014 Module 1: Introduction to Networking Management Overview • What is network management? • Why manage network? • Challenges in managing enterprise networks • Network management areas • Implications for management 1 9/7/2014 What is Network Management ? • In general, network management is a service that employs a variety of tools tools, applications, applications and devices to assist human network managers in monitoring and maintaining the performance of networks. • Network management means different things to different people. In some cases, it involves a solitary network consultant monitoring network activity with an outdated protocol analyser. In other cases, network management involves a distributed database, auto-polling of network devices, and high-end workstations generating real-time graphical views of network topology changes and traffic traffic. *Ref CISCO Systems Website http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/nmbasics.htm#xtocid4 What is Network Management – 2 • Network management refers to the activities, methods, procedures, d and d ttools l th thatt pertain t i tto th the operation, ti administration, maintenance and provisioning of networked systems. • Functions performed as part of network management include: – controlling, planning, allocating, deploying, coordinating and monitoring the resources of a network, – network planning, frequency allocation and predetermined traffic routing to support load balancing, – cryptographic t hi kkey di distribution, t ib ti authorisation th i ti and d security it management – configuration management, fault management, performance management, bandwidth management; and accounting management 2 9/7/2014 Why bother with Network Performance Management ? Typical Performance Metrics • • • • • • • • • • Mean Time Between Failures (MTBF) Mean Time to Repair (MTTR) Response Time Speed Percentage Availability Reliability Errored Seconds Bit E Error R Rate t (BER) Voice Quality Others ? 3 9/7/2014 When things Fail This is an example of the case where if any one device or process fails the whole device or process has failed. When things Fail This is an example of the case where if any one device or process fails the whole device or process has failed. 4 9/7/2014 When things Fail This is an example of the case where all devices must fail for the whole device or process to fail. However ! Network Performance Management Costs Money – – – – – – Administrative Overheads Equipment Links and bearers Protocol Overheads Processing and Software Overheads Etc. 5 9/7/2014 The Process for Business Grade Networking (Cisco Systems, 2010) Why Manage your Network? • Managing the network overall: – Investments in faster servers servers, better protocols protocols, high high-speed speed backbones and virtualised services have turned yesterday’s low-speed, data-only networks into information technology platforms supporting a multitude of business services. – The redundancy and rerouting designed into these networks has mostly hidden actual hardware or circuit outages from end users. • Managing network performance: – The bigger challenge is how to address the often-persistent intermittent application li i d degradations d i that h represent a threat h to revenue, customer service and reputation. – The packets transporting business applications throughout a global network can be leveraged for analysis to achieve the highest level of a network operations maturity process. – The reward for using these packets as evidence and implementing a mature management process for troubleshooting will be dramatic reductions in mean time to restore (MTTR) application services. (Haggerty, 2008) 6 9/7/2014 High Cost of NonResponsiveness • Corporations Can Lose Millions of Dollars in Just One Hour If a Mission-Critical Application Becomes Unavailable or Does Not Run Correctly, Quickly or Completely Business Brokerage Operations Credit Card Authorisation Average US$ Cost per Hour $6.45 Million $2.6 Million Home Shopping TV $113,000 Pay-per-View TV $150,000 Catalog Sales $90,000 Airline Reservations $89,500 Tele-Ticket Sales $69,000 Package Shipping $28,000 ATM Fees $14,000 Source: Contingency Planning Research How Much Management? • Today’s computer and communications software ft and d hardware h d h have very llarge amounts of management capability built in. • It is also possible to install additional software and hardware and other tools for the express purpose of more detailed management. 7 9/7/2014 5 Challenges in Managing Enterprise Networks • Lack of high-definition visibility – A minute is an eternity for applications like automated market trading trading, and waiting for medical images to appear can impact treatment options • A unified network can no longer be managed as multiple traffic silos – In the modern, fully converged IP network, voice, video and data compete for common resources and can affect one another’s –even if individual applications seem to be working properly • You cannot manage what you cannot see – In dealing with service-oriented architecture-based applications, trouble-shooting must start at the virtual service network level –not the physical network level • Monitoring health of infrastructure elements is helpful – But also depends on the interaction and communications between network elements • Must be able to identify business use vs. recreational use vs. security threats – Recreational use often presents itself as legitimate traffic from users to a legacy management tool The Impact of Unmanaged Services Network Outages • Cost money directly – E.g. banks, airlines, transaction services • Cost money or Customers Indirectly – E.g. ISP’s, Telco’s etc. Outages may ultimately cause an organisation to go out of business 8 9/7/2014 Views of Network Management • CEO view – financial management g of corporate p comms network • management of orders, inventory, accounting information • CIO view – corporate budget – end-user perspective – providing more service with less money • End User view – require data comms infrastructure to be working at all times Outsourcing • Work does not stop when outsourcing to S i P Service Providers id • No Service Providers will sign Unlimited Liability Liquidated Damages contracts • Network outages can kill companies 9 9/7/2014 Network Management Requirements • • • • • Fault Management Accounting Management Configuration and Name Management Performance Management Security Management Fault Management • A fault is an abnormal condition that requires management attention (or action) to repair. How do you define abnormal ? 10 9/7/2014 Setting the Threshold • It is important to set the threshold for alarm indications to an appropriate level level, so that significant faults and quality of service issues can be dealt with without the network manager becoming overloaded with the relevant messages. • Excessive network management, g , and excessive network management messages can actually degrade overall network performance. Accounting Management • Reasons for accounting management: – Internal charge backs on net network ork use se – 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 – The network manager is in a better position to plan for network growth if user activity is known in sufficient detail. 11 9/7/2014 Configuration Management • Concerned with: – initialising a network and gracefully shutting down part or all of the network – maintaining, adding, and updating the relationships among components and the status of components themselves during network t k operation ti Adds, Moves and Changes Security Management • Concerned with: – monitoring and controlling access to networks – generating, distributing, and storing encryption keys – access to all or part of the network management information – collection, storage, and examination of audit records and security logs 12 9/7/2014 Performance Management • Some typical issues of concern to the network manager include: – – – – – – What is the level of capacity utilisation? Is there excessive traffic? Has throughput been reduced to unacceptable levels? Are there bottlenecks? Is response time increasing ? Are customers getting what they paid for ? • Network managers need performance statistics to help them plan, manage and maintain large networks Web-based Network Management • User interface using web technology – HTML pages delivered via HTTP over TCP – platform independence – network management information stored on web servers 13 9/7/2014 Key challenges • Shift to LANs and the Internet – Large scale move from using mainframes and terminals to PCs, LANs and the Internet. • • Focus on integration of organisational networks and applications. Main problems: – – • Future of network management lies in the successful management of multiple clients and servers over LANs, BN’s, and Internet Not all LANs use the same architecture More types of network technology used, the more complex network management becomes Integrating LANs LANs, WANs and Internet – – – Both LAN/Web and WAN managers to recognise that they no longer have total power Must adopt a written charter to define its purpose, operational philosophy, and long range goals Must develop individual procedures to implement policies (Copyright 2010 John Wiley & Sons, Inc) Key Challenges… • Integrating Voice & Data –Traditionally, traditional voice and data networks (e.g., POTS and LANs) were handled by separate managers – Voice Communication Manager in Facilities Department: • Supervised telephone switchboard, coordinated installation and maintenance of the voice network – Data Communication Manager (IT department): • Installed own data circuit, installed and maintained computers • Now, organisations realise benefits of integrating voice and data management function – Simplifies the network, and can lower network costs – Eliminates one department – Is now more typically found in network management (Copyright 2010 John Wiley & Sons, Inc) 14 9/7/2014 Improving performance • General activities to improve performance that cut across the different types of networks: – P Policy-based li b d management-Setting t S tti priority i it policies li i ffor network t k traffic in software and configures devices using QoS capabilities in TCP/IP and/or ATM • Example-Manager: Sets videoconferencing traffic as the highest priority since delays will have the highest impact on the performance of that application – Server load balancing-Used to allocate incoming requests for network servers and uses a separate load balancing server (or a router/switch) with a special software – Service-level Service level agreements-Signed agreements Signed between the organization and its service providers (ISP or common carriers) • Specify the exact type of performance and fault conditions that the organization will accept • Examples-Availability must be 99% or higher • Maximum allocable response time must be lower than 2 minutes (Copyright 2010 John Wiley & Sons, Inc) Cost Management • One of the most challenging g g areas over the past few years – Traffic growing more rapidly than the budget – Managers are forced to provide greater capacity at an ever lower cost per megabyte (Copyright 2010 John Wiley & Sons, Inc) 15 9/7/2014 Sources of Cost • Total Cost of Ownership (TCO) – A measure off how h much h it costs per year to keep one computer operating – Includes cost of • Repairs and software/hardware upgrades • Support staff (maintain, install administer, install, administer etc) • Training and technical support • Time “wasted” by the user when problems occur (Copyright 2010 John Wiley & Sons, Inc) Implications for Management • Network management requires – – – – A good understanding of networking technologies A ability An bili to work k with i h end d users and d management An understanding of key elements driving network costs Requires special skill to explain the business value of the networks to senior management – Needed to justify increased cost of management • Recommendations – Develop strong relationships with only few vendors – Purchase technologies that will provide strong network management capabilities – Use powerful design and management tools-Saves money in the long run (Copyright 2010 John Wiley & Sons, Inc) 16 9/7/2014 References • CA (2008) Strategic Planning for Network and Systems M Management, t TechTargetWhite T hT tWhit Paper, P Available A il bl online: li : http://go.techtarget.com/r/4340222/3758610/1 • Cisco (2008) Network Management Basics, InInternetworking Technology Handbook, Available online: http://www.cisco.com/en/US/docs/internetworking/technology/ handbook/NM-Basics.html • Haggerty, E. (2008) Overcoming Today’s IP Network Challenges, Newsfactor.com White Paper, Available online: htt // http://www.newsfactor.com/story.xhtml?story_id=013000FA05 f t / t ht l? t id 013000FA05 2E&page=1 • Wikipedia (2008) Network Management, Available online: http://en.wikipedia.org/wiki/Network_management References • • • • • • • Stallings, W, 2005, Section 19.1 –‘Business Data Communications’, 5th edn, Pearson Education Inc., New Jersey. Cisco Systems Inc, 2006, ‘Simple Network Management Protocol’, Internetworking Technologies Handbook, Chapter 56, Cisco Systems Inc. www.Cisco.com. FitzGerald, J and Dennis, A, 2005, Chapter 13 –‘Business Data Communications and Networking’, 8th edn, John Wiley & Sons, Inc., New Jersey. FitzGerald, J and Dennis, A, 2010, Chapter 12 –‘Business Data Communications and Networking’, 10th edn, John Wiley & Sons, Inc., New Jersey. T Tang, E, E Eddie, Eddi B and dM Matt, tt B 2006, 2006 ‘Comparison ‘C i off SNMP V Versions i 1 1,2 2 and 3’; WindowsNetworkig.com n.d,‘Understanding the SNMP Protocol’ www.windowsnetworking.com CP3340 Communication Systems-‘SNMP Environment’, www.scit.wlv.ac.uk 17