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Network Traffic Measurement
In computer networks, network traffic measurement is the process of measuring the amount and type of traffic on a particular network. This is especially important with regard to effective bandwidth management. Techniques Network performance could be measured using either active or passive techniques. Active techniques (e.g. Iperf) are more intrusive but are arguably more accurate. Passive techniques have less network overhead and hence can run in the background to be used to trigger network management actions. Measurement studies A range of studies have been performed from various points on the Internet. The AMS-IX (Amsterdam Internet Exchange) is one of the world's largest Internet exchanges. It produces a constant supply of simple Internet statistics. There are also numerous academic studies that have produced a range of measurement studies on frame size distributions, TCP/UDP ratios and TCP/IP options. Tools Various software tools are available to measure network traffic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Networks
A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must be connected by wired media like copper cables, optical fibers, or by wireless communication. The devices may be connected in a variety of network topologies. In order to communicate over the network, computers use agreed-on rules, called communication protocols, over whatever medium is used. The computer network can include personal computers, servers, networking hardware, or other specialized or general-purpose hosts. They are identified by network addresses and may have hostnames. Hostnames serve as memorable labels for the nodes and are rarely changed after initial assignment. Network addresses serve for locating and identifying the nodes by communication protocols such as the Internet Protocol. Computer networks may be classified by many criteria, including the transmission medium used to carr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Traffic Control
In computer networking, network traffic control is the process of managing, controlling or reducing the network traffic, particularly Internet bandwidth, e.g. by the network scheduler.M. Noormohammadpour, C. S. Raghavendra"Datacenter Traffic Control: Understanding Techniques and Trade-offs,"IEEE Communications Surveys & Tutorials, vol. PP, no. 99, pp. 1-1. It is used by network administrators, to reduce congestion, latency and packet loss. This is part of bandwidth management Bandwidth management is the process of measuring and controlling the communications (traffic, packets) on a network link, to avoid filling the link to capacity or overfilling the link,https://www.internetsociety.org/wp-content/uploads/2017/08/BWro .... In order to use these tools effectively, it is necessary to measure the network traffic to determine the causes of network congestion and attack those problems specifically. Network traffic control is an important subject in datacenters as it is neces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Performance Management
Business performance management (BPM) (also known as corporate performance management (CPM) enterprise performance management (EPM),) is a management approach which encompasses a set of processes and analytical tools to ensure that a business organization's activities and output are aligned with its goals. BPM is associated with business process management, a larger framework managing organizational processes. It aims to measure and optimize the overall performance of an organization, specific departments, individual employees, or processes to manage particular tasks. Performance standards are set by senior leadership and task owners which may include expectations for job duties, timely feedback and coaching, evaluating employee performance and behavior against desired outcomes, and implementing reward systems. BPM can involve outlining the role of each individual in an organization in terms of functions and responsibilities. History By 2017, Gartner had reclassified CPM as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Packet Sniffer
A packet analyzer (also packet sniffer or network analyzer) is a computer program or computer hardware such as a packet capture appliance that can Traffic analysis, analyze and Logging (computing), log traffic that passes over a computer network or part of a network. Packet capture is the process of intercepting and logging traffic. As data streams flow across the network, the analyzer captures each Network packet, packet and, if needed, decodes the packet's raw data, showing the values of various fields in the packet, and analyzes its content according to the appropriate Request for Comments, RFC or other specifications. A packet analyzer used for intercepting traffic on wireless networks is known as a wireless analyzer - those designed specifically for Wi-Fi networks are Wi-Fi analyzers. While a packet analyzer can also be referred to as a Network analyzer (other), network analyzer or protocol analyzer these terms can also have other meanings. Protocol analyzer can t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Simulation
In computer network research, network simulation is a technique whereby a software program replicates the behavior of a real network. This is achieved by calculating the interactions between the different network entities such as routers, switches, nodes, access points, links, etc. Most simulators use discrete event simulation in which the modeling of systems in which state variables change at discrete points in time. The behavior of the network and the various applications and services it supports can then be observed in a test lab; various attributes of the environment can also be modified in a controlled manner to assess how the network/protocols would behave under different conditions. Network simulator A network simulator is a software program that can predict the performance of a computer network or a wireless communication network. Since communication networks have become tool complex for traditional analytical methods to provide an accurate understanding of system behav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Scheduler
A network scheduler, also called packet scheduler, queueing discipline (qdisc) or queueing algorithm, is an arbiter on a node in a packet switching communication network. It manages the sequence of network packets in the transmit and receive queues of the protocol stack and network interface controller. There are several network schedulers available for the different operating systems, that implement many of the existing network scheduling algorithms. The network scheduler logic decides which network packet to forward next. The network scheduler is associated with a queuing system, storing the network packets temporarily until they are transmitted. Systems may have a single or multiple queues in which case each may hold the packets of one flow, classification, or priority. In some cases it may not be possible to schedule all transmissions within the constraints of the system. In these cases the network scheduler is responsible for deciding which traffic to forward and what ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Monitoring
Network monitoring is the use of a system that constantly monitors a computer network for slow or failing components and that notifies the network administrator (via email, SMS or other alarms) in case of outages or other trouble. Network monitoring is part of network management. Details While an intrusion detection system monitors a network threats from the outside, a network monitoring system monitors the network for problems caused by overloaded or crashed servers, network connections or other devices. For example, to determine the status of a web server, monitoring software may periodically send an HTTP request to fetch a page. For email servers, a test message might be sent through SMTP and retrieved by IMAP or POP3. Commonly measured metrics are response time, availability and uptime, although both consistency and reliability metrics are starting to gain popularity. The widespread addition of WAN optimization devices is having an adverse effect on most network monitorin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Management
Network management is the process of administering and managing computer networks. Services provided by this discipline include fault analysis, performance management, provisioning of networks and maintaining quality of service. Network management software is used by network administrators to help perform these functions. Technologies A small number of accessory methods exist to support network and network device management. Network management allows IT professionals to monitor network components within large network area. Access methods include the SNMP, command-line interface (CLI), custom XML, CMIP, Windows Management Instrumentation (WMI), Transaction Language 1 (TL1), CORBA, NETCONF, RESTCONF and the Java Management Extensions (JMX). Schemas include the Structure of Management Information (SMI), YANG, WBEM, the Common Information Model ( CIM Schema), and MTOSI amongst others. Value Effective network management can provide positive strategic impacts. For ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Measuring Network Throughput
Throughput of a network can be measured using various tools available on different platforms. This page explains the theory behind what these tools set out to measure and the issues regarding these measurements. Reasons for measuring throughput in networks. People are often concerned about measuring the maximum data throughput in bits per second of a communications link or network access. A typical method of performing a measurement is to transfer a 'large' file from one system to another system and measure the time required to complete the transfer or copy of the file. The throughput is then calculated by dividing the file size by the time to get the throughput in megabits, kilobits, or bits per second. Unfortunately, the results of such an exercise will often result in the goodput which is less than the maximum theoretical data throughput, leading to people believing that their communications link is not operating correctly. In fact, there are many overheads accounted for in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NetFlow
NetFlow is a feature that was introduced on Cisco routers around 1996 that provides the ability to collect IP network traffic as it enters or exits an interface. By analyzing the data provided by NetFlow, a network administrator can determine things such as the source and destination traffic, class of service, and the causes of congestion. A typical flow monitoring setup (using NetFlow) consists of three main components: * Flow exporter: aggregates packets into flows and exports flow records towards one or more flow collectors. * Flow collector: responsible for reception, storage and pre-processing of flow data received from a flow exporter. * Analysis application: analyzes received flow data in the context of intrusion detection or traffic profiling, for example. Protocol description Routers and switches that support NetFlow can collect IP traffic statistics on all interfaces where NetFlow is enabled, and later export those statistics as NetFlow records toward at least one Ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IP Flow Information Export
Internet Protocol Flow Information Export (IPFIX) is an IETF protocol, as well as the name of the IETF working group defining the protocol. It was created based on the need for a common, universal standard of export for Internet Protocol flow information from routers, probes and other devices that are used by mediation systems, accounting/billing systems and network management systems to facilitate services such as measurement, accounting and billing. The IPFIX standard defines how IP flow information is to be formatted and transferred from an exporter to a collector. Previously many data network operators were relying on Cisco Systems' proprietary NetFlow technology for traffic flow information export. The IPFIX standards requirements were outlined in the original RFC 3917. Cisco NetFlow Version 9 was the basis for IPFIX. The basic specifications for IPFIX are documented in RFC 7011 through RFC 7015, and RFC 5103. Architecture The following figure shows a typical architecture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Content Filtering
An Internet filter is software that restricts or controls the content an Internet user is capable to access, especially when utilized to restrict material delivered over the Internet via the Web, Email, or other means. Such restrictions can be applied at various levels: a government can attempt to apply them nationwide (see Internet censorship), or they can, for example, be applied by an Internet service provider to its clients, by an employer to its personnel, by a school to its students, by a library to its visitors, by a parent to a child's computer, or by an individual user to their own computers. The motive is often to prevent access to content which the computer's owner(s) or other authorities may consider objectionable. When imposed without the consent of the user, content control can be characterised as a form of internet censorship. Some filter software includes time control functions that empowers parents to set the amount of time that child may spend accessing the Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
