Considerations for calculating bandwidth
What is Data Flow Diagram?
Data Flow Diagram is a type of diagram chart that shows the movement ofinformation from one place to another as part of a particular processor ingeneral. In other cases — DFD can show how different departments of theorganization cooperate – it makes things clear and coherent. The entire method was devised back in the 1970s as a mean to streamlinedocumenting and subsequent presentation of the workflow processes. * Dataflow diagram was first described in a book by Ed Yourdon and Larry Constantine, “Structured Design.” * They took “data flow graph” models of computation of David Martin and Gerald Estrin as the foundation. * Other significant sources of inspiration were Object-Oriented Analysis and Design and Structured Systems Analysis and Design Methods. * The method was further perfected by Tom DeMarco, Chris Gane, and Trish Sarson, who devised a practical alphabet of symbols and notations for Data Flow Diagrams.At this point, DFD is more or less replaced by Business Process Model andNotation aka BPMN and is rarely beyond showing the big picture. However, Dataflow diagrams is a good entry point for those who starts studyingBusiness Analysis and business process visualization. DFD shows what goes where and how and explains how exactly something operatesand what happens in the process.> Diagrams depict relationships between elements of the system in detail and> an easy-to-follow manner.There is an easy way of explaining what DFD is. It makes things much moreexplicit and coherent. * In Business Analysis – DFD is used for the assessment of existing and projected systems and its elements. Diagramming provides a useful toolset for exposing possible weaknesses and structural flaws. * In Software Development – DFD is used to explain and visualize the requirements of the projects — from the business perspective and a technical point of view. This feature allows hatching through and through step by step plan for the development of each element.Data Flow Diagram can be a helpful and easy way for project owners toconceptualize their projects and think through every important detail. It allows modeling of the processes on a different level and puts them intothe perspective of the overall architecture of the project. DFD is especially helpful in the initial stages of the project when elementsof the processes are in the process of validation and settling down into thesystems.
How bandwidth works
The more bandwidth a data connection has, the more data it can send andreceive at one time. Bandwidth can be compared to the amount of water that canflow through a water pipe. The bigger the pipe, the more water can flowthrough it at one time.Bandwidth works on the same principle. So, the higher the capacity of thecommunication link, or pipe, the more data can flow through it per second.End users pay for the capacity of their network connections. Therefore, thegreater the capacity of the link, the more expensive it is.
Bandwidth vs. speed
The terms bandwidth and speed are often used interchangeably – but notcorrectly. The cause of the confusion may be due, in part, to their use inadvertisements by internet service providers (ISPs) that refer to greaterspeeds when they actually mean bandwidth. Essentially, speed refers to therate at which data can be sent, while the definition of bandwidth is thecapacity for that speed. To use the common water metaphor, speed refers to howquickly water is flowing through a pipe; bandwidth refers to the diameter ofthe pipe. In order to avoid confusion, it makes more sense to use the termsbandwidth (or bandwidth capacity) and network speed, rather than bandwidthspeed.
Why bandwidth is important
In any given deployment location, such as a house or business, there arebandwidth limits. That is, there is only so much space in the pipe for thedata to flow. Because of this reason, multiple devices in a single locationmust share the bandwidth. Some devices, such as a television, are bandwidthhogs, while tablets typically use far less in comparison. Although speed andbandwidth are not interchangeable, greater bandwidth is essential if tolerablespeed is to be maintained on multiple devices.
How to measure bandwidth
While bandwidth is traditionally expressed in bits per second (bps), modernnetwork links have greater capacity, which is typically measured in millionsof bits per second (megabits per second, or Mbps) or billions of bits persecond (gigabits per second, or Gbps).Bandwidth connections can be symmetrical, which means the data capacity is thesame in both directions to upload or download data, or asymmetrical, whichmeans download and upload capacity are not equal. In asymmetrical connections,upload capacity is typically smaller than download capacity.
Considerations for calculating bandwidth
Technology advances have made some bandwidth calculations more complex, andthey can depend on the type of network link being used. For example, opticalfiber using different types of light waves and time-division multiplexing cantransmit more data through a connection at one time, which effectivelyincreases its bandwidth. In wireless networks, bandwidth is defined as thespectrum of frequencies that operators license from the Federal CommunicationsCommission (FCC) and the National Telecommunications and InformationAdministration (NTIA) for use in mobile services in the U.S.Effective bandwidth, which is the highest reliable transmission rate a linkcan provide, can be measured using a bandwidth test in which the link’scapacity is determined by repeatedly measuring the time required for aspecific file to leave its point of origin and successfully download at itsdestination.In addition to testing, organizations need to calculate how much bandwidththey need to run all the applications on their networks. To find out how muchcapacity they need, organizations must calculate the maximum number of userswho might be using the network connection at one time and then multiply thatnumber times the bandwidth capacity required by each application.To calculate needed bandwidth for the cloud, it’s important to know thecapacity needed to send and receive traffic from public clouds. Capacity canbe affected by any congestion on the connections used to reach public cloudproviders, particularly if that data is traveling over the internet.When looking into how much bandwidth a specific application will need, thereare two basic steps to calculating bandwidth requirements: 1. Determine the amount of available network bandwidth, expressed in bytes per second (Bps). 2. Determine the average utilization required by the specific application, expressed in bytes per second.After determining the network’s bandwidth, it is necessary to see how muchbandwidth each application is using. Bandwidth testing can be used to detectthe number of bytes per second the application sends across the network.
Bandwidth on demand
The maximum available bandwidth for dedicated communication links is typicallysold at a set price by the month. However, bandwidth on demand — also calleddynamic bandwidth allocation, or burstable bandwidth — is an option thatenables subscribers to increase the amount of available bandwidth at specifictimes or for specific purposes. Bandwidth on demand is a technique that canprovide additional capacity on a communications link to accommodate bursts indata traffic that temporarily require more bandwidth.Rather than overprovisioning the network with expensive dedicated links,bandwidth on demand provided by service providers is frequently used in widearea networks (WANs) to increase capacity as needed for a particular event orat a particular time of day. Using this technique, bandwidth on a sharedtelecommunications network can be increased, and users pay for only theadditional bandwidth they consume.Bandwidth on demand is available through many service providers because thenetwork links they provide to customers have additional bandwidth availablethrough them, but customers pay only for the capacity they need. For example,a 100 Mbps link might be able to burst up to a gigabit because the serviceprovider’s connection has available capacity. If a user needed more than theabsolute maximum bandwidth available on that link, another physical connectionwould be required.Occasionally, a service provider will enable customers to burst above theirsubscribed bandwidth cap without charging additional bandwidth usage fees.
ISPs or network administrators sometimes intentionally adjust the speed — upor down — of data traveling over the network, a measure known as bandwidththrottling. There are different reasons for bandwidth throttling, includinglimiting network congestion, particularly on public access networks. ISPs mayuse bandwidth throttling to reduce usage of a particular user or class ofusers. For example, with tiered pricing, a service provider can offer a menuof upload and download bandwidth. ISPs can also throttle bandwidth to even outusage across all users on the network.The use of bandwidth throttling has been criticized by net neutralityadvocates, who say that political or economic motivations are behind thepractice of bandwidth throttling and that they unfairly target segments of thepopulation.To see if an ISP is throttling bandwidth, a speed test can be run. Speed testsmeasure the speed between a device and a test server, using a device’sinternet connection. ISPs offer speed tests from their internet sites, andindependent tests are also available from services such as Speedtest. Becausemany factors can affect the results of a speed test, it is generallyrecommended to perform multiple tests at different times of the day and engagedifferent servers available through the speed test site.Some people also suggest installing a virtual private network (VPN) if you’relooking for more accurate results of your speed test.There are also network bandwidth monitoring tools available to help identifyperformance issues, such as a faulty router or a virus-infected computer onthe network. As noted above, bandwidth monitoring can also help networkadministrators better plan for future network growth, seeing where in thenetwork the bandwidth capacity is most needed. Monitoring tools can also helpadministrators see if their ISP is living up to the service-level agreement(SLA) in their contract.
Data transfer throttling
Data transfer throttling – the intentional restriction of the amount ofdigital data, particularly for the purposes of preventing spam or bulk emailtransmission through a network server – can be considered another form ofbandwidth throttling. If it is implemented on a large enough scale, datatransfer throttling can control the spread of computer viruses, worms or othermalware through the internet.Monitoring Bandwidth in Wi-Fi Networks: A Guide
Monitoring Bandwidth in Wi-Fi Networks: A Guide
I’m a SEO Specialist, Web developer and Data Analyst since 6 years.When building a WLAN infrastructure, you need to make a precise analysis ofthe bandwidth requirements to balance performance and cost correctly.Bandwidth plays a fundamental role in the design and maintenance of afunctional network.In this article, we will present why it is important to consider andappropriately monitor the bandwidth requirements of the WiFi network you aregoing to deploy, to perform the most reliable network experience.
What is the bandwidth? And, the network bandwidth?
Bandwidth is the capacity of a channel to transmit data. During thetransmission, the information is sent in a binary system, a language thatencodes data using only two symbols (often defined as “1” and “0”, or “on” and“off”), each of which is called a bit.The basic unit of this language, the byte, is composed of 8 bits. Thebandwidth determines, therefore, the number of bytes that can be transmittedon the connection. The unit of measurement is the bits per second (bps). Forexample, a low definition video lasting 15 seconds, weighing 1 Megabyte, canbe downloaded from an Internet site on your computer in 3-5 minutes if theconnection is made via modem (56 kbps) or ISDN line (from 64 to 128 kbps). Thesame action takes a few seconds instead if the connection is broadband, likethe one with the optical fibers (over 1000 Gbps).Network bandwidth is the capacity of a network communications link to transmitthe maximum volume of data from one point to another over a computer networkor Internet connection in a given amount of time, usually one second.Bandwidth has the same meaning of capacity and defines the data transfer rate.> Bandwidth, though, is not a measure of network speed.As a matter of fact, the words “bandwidth” and “speed” are often misused assynonymous. The explanation of this misunderstanding can be, in part, due totheir use in advertisements by ISPs that refer to speeds when they meanbandwidth. Indeed, speed refers to the rate at which data can be sent, whilethe definition of bandwidth is the capacity for that speed.
Why is it so important to check network bandwidth requirements before
deploying a network?Bandwidth can be compared to the volume of water that can flow through a waterpipe. If the pipe is bigger, the water can flow in a massive quantity throughit at one time. Bandwidth functions in the same way. So, the more bandwidth adata connection has, the more data it can send and receive at one time.Consider that in any kind of deployment location, there are bandwidth limits.This means that there is a constraint to space for the data to flow.Therefore, multiple devices in a single area must share the bandwidth. Somedevices request much more bandwidth than others. Greater bandwidth isabsolutely necessary if proper speed must be maintained on different devices.