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Performance Management (Best Practices) REF:www.cisco.com Document ID 15115 Introduction • Performance Management involves optimization of network response time and management of consistency and quality of individual and overall network services • The most important service is the need to measure the user/application response time. • For most users, response time is the critical performance success factor. Background (1) • Performance problems often correlate with capacity of resources (CPU, RAM, Bandwidth). – In networks, this is typically bandwidth and data that must wait in queues before it can be transmitted through the network. – In voice applications, this wait time almost certainly impacts users because factors such as delay and jitter affect the quality of the voice call. Performance management issues • • • • User performance Application performance Capacity planning Proactive fault management • It is important to note that with newer application like video and voice performance management is the key success Performance management process flow (1) Develop a network management concept of operation Measure Performance Perform a Proactive Fault Analysis Performance management process flow (2) 1 develop a network management concept of operation – Define the required features : Services, Scalability objectives – Define availability and network management objectives – Define performance SLAs and Metrics – Define SLA Performance management process flow (3) 2 Measure Performance – Gather network baseline data – Measure availability – Measure response time – Measure accuracy – Measure utilization – Capacity planning Performance management process flow (4) 3 perform a proactive fault analysis – Use threshold for proactive fault management – Network management implementation – Network operation metrics Performance management process flow (5) Develop a network management concept of operation Measure Performance Perform a Proactive Fault Analysis Develop a network management concept of operation • The purpose of this document is to describe the overall desired system characteristics from an operational standpoint • The focus of this document is to form the long range operational planning activities for network management and operation. • It also provides guidance for the development of all subsequent definition documentation, such as service level agreements. Define the required features: Services, Scalability Objectives • Define services objectives : – To describe what the objectives that networks and services are supposed to be – This step requires that you understand applications, basic traffic flows, user and site counts, and required network services. • Define scalability objectives: – to help network engineers design networks that meet future growth requirement and not experience resource constraint (media capacity, number of routes and etc) Define availability and network management Objectives (1) • Defining availability objectives is to explain the level of services needed (service level requirements) • This helps to ensure the solution meets end availability requirements • It might lead to – categorize different class of service for each availability requirement – Higher availability objective might necessitate increased redundancy and support procedures Define availability and network management objectives (2) • Define manageability objectives to ensure that overall network management does not lack management functionality • It might lead to – Have understand the process and tools used for organization – Uncover all important MIB or network tool information required to support a potential network – Have training required to support the new network service Define performance SLAs and Metrics • Performance SLAs and metrics help define and measure the performance of new network solutions to ensure they meet performance requirements. • The performance SLAs should include the average expected volume of traffic, peak volume of traffic, average response time and maximum response time allowed Define SLAs (1) • SLA (Service Level Agreement) – Customer (Enterprise) , SLM (Service Level Management) Provider • SLA include definitions for problem types and severity and help desk responsibilities – Escalation path, time before escalation at each tier support level – Time to start work on the problem – Time to close target based on priority – Service to provide in the area of capacity planning, hardware replacement Performance management process flow Develop a network management concept of operation Measure Performance Perform a Proactive Fault Analysis Measure Performance • Gather Network Baseline data – Perform a baseline of the network before and after a new solution deployment – A typical router/switch baseline report includes capacity issues related to CPU, memory, buffer, link/media utilization, throughput – Application baseline: bandwidth used by app per time period Measure availability • Availability is the the measure of time for which a network system or application is available to a user – Coordinate the help desk phone calls with the statistics collected from managed devices – Check scheduled outages – Etc Measure Response Time • Network response time is the time required to travel between two points • Simple level – pings from the network management station to key points I the network. (not accuracy) • Server-centric polling : SAA (Service Assurance Agent) on router (Cisco) to measure response time to a destination device • Generate traffic that resembles the particular application or technology of interest Measure accuracy • Accuracy is the measure of interface traffic that does not result in error and can be expressed in term of percentage • Accuracy = 100 – error rate • Error rate = ifInErrors * 100 / (ifInUcastPkts + IfInNUcastPkts) Measure Utilization (1) • Utilization measure the use of a particular resource over time • Percentage in which the usage of a resource is compared with its maximum operational capacity • High utilization is not necessarily bad • Sudden jump in utilization can indicate unnormal condition Measure Utilization (2) • Input utilization = ifInOctets *8*100/(time in second)*ifSpeed • Output Utilization ifOutOctets *8*100/(time in second)*ifSpeed Capacity planning • The following are potential areas for concern: – CPU – Backplane or I/O – Memory – Interface and pip sizes – Queuing, latency and jitter – Speed and distance – Application characteristics Performance management process flow Develop a network management concept of operation Measure Performance Perform a Proactive Fault Analysis Perform a Proactive fault analysis • One method to perform fault management is through the use of RMON alarms and event groups • Distributed management system that enables polling at a local level with aggregation of data at a manager to manager Use threshold for proactive fault management (1/2) • Threshold is the point of interest in specific data stream and generate event when threshold is triggered • 2 classes of threshold for numeric data – Continuous threshold apply to continuous or time series data such as data stored in SNMP counter or gauges – Discrete threshold apply to enumerated objects or discrete numeric data such as Boolean objects Use threshold for proactive fault management (2/2) • 2 different forms of continuous threshold – Absolute :use with gauges – Relative (delta): use with counter • Step to determine threshold – 1 select the objects – 2 select the devices and interfaces – 3 determine the threshold values for each object or interface – 4 determine the severity for the event generated by each threshold Network management implementation • The organization should have an implemented network management system. • SNMP/RMON or other network management system tools Network operation metrics (1/2) • Number of problems that occurs by call priority • Minimum, maximum and average time to close in each priority • Breakdown of problems by problem type (hardware, software crash, configuration, power user error) Network operation metrics (2/2) • Breakdown of time to close for each problem type • Availability by availability or SLA • How often you met or missed SLA requirements Performance Management Indicator Indicators for performance management (1/3) • Performance indicators provide mechanism by which an organization can measure critical success factors. • They are the followings: • Document the network management business objectives • Create detailed and measurable service level objectives Indicators for performance management (2/3) • Provide documentation the service level agreement (SLA) with charts or graphs that show the success or failure of how these agreements are met over the time • Collect a list of the variables for the baseline such as polling interval, network management overhead incurred, possible trigger threshold – whether the variable is used as a trigger for a trap, and trending analysis used against each variable Indicators for performance management (3/3) • Have a periodic meeting that reviews the analysis of the baseline and trends. • Have a what−if analysis methodology documented. – This should include modeling and verification where applicable • When thresholds are exceed, develop documentation on the methodology used to increase network resources. – One item to document is the time line required to put in additional WAN bandwidth and a cost table Document the network management business objectives (1/3) • This document is the organization network management strategy and should coordinate the overall business goals of network operations, engineering, design, other business units and the end users. • It enable the organization to form the long range planning activities for network management and operation. Document the network management business objectives (2/3) • Identify a comprehensive plan with achievable goals • Identify each business service/application that require network support • Identify those performance-based metric needed to measure service Document the network management business objectives (3/3) • Plan the collection and distribution of the performance metric • Identify the support needed for network evaluation and user feedback • Have documented, detailed and measurable SLA objectives Document the Service Level Agreements • Before document the SLA, you must define the service level objectives metrics • This document should be available to users for evaluation to provide feedback for variables needed to maintain the service agreement level • SLAs are living agreement – What works today might become obsolete tomorrow Create a list of variables for the baseline • This list includes items such as – polling interval – Network management overhead incurred – Possible trigger thresholds – Trending analysis used against each variable – Router health – Switch health – Routing information – Utilization – delay Reviews the baseline and trends • Network management personnel should conduct meeting periodically (operational and planning) • Also include the review of SLA Document a what-if analysis methodology • A what-if analysis involves modeling and verification of solutions. • It includes the major questions, the methodology, data sets and configuration file • The main point is that he what-if analysis is an experiment hat someone else should be able to recreate with the information provided in the document Document the methodology used to increase network performance • This document includes additional WAN bandwidth and a cost table that helps increase the bandwidth for a particular type of link • It helps the organization realize how much time and money it costs to increase the bandwidth • Periodic review this document to ensure that it remain up to date