Fixed or Burstable Bandwidth? Which Is Right for You?

Control your company's bandwidth usage to maximize network efficiency and stakeholder satisfaction by leveraging the advantages of fixed or burstable bandwidth.

fireworks bursting
Rob Rodier

Nov 17, 2021


Now that your business has completed its digital transformation, you may have turned your attention to its usable bandwidth. As you know, more bandwidth means faster network data speeds, a higher QoE, and a better user experience (UX). Luckily, you can control (more or less) your company's bandwidth usage to maximize network efficiency and stakeholder satisfaction.

Data-intensive applications such as video conferencing and VoIP tax network capacity. While network admins can prioritize network traffic with traffic shaping, increased network usage and today's deluge of generated data will eventually overwhelm legacy network configurations based on outdated usage patterns.

If your business is currently evaluating its bandwidth usage, consider a "burstable" bandwidth billing plan from your ISP instead of fixed bandwidth billing. Burstable bandwidth measures bandwidth according to peak use. This billing model permits a user to briefly exceed a specified usage level without incurring a higher committed information rate (CIR) from an ISP. With burstable billing, your business doesn't have to subscribe to a continuous, higher-priced level of service. In the wild, what you see is that instead of a company purchasing a 1 gbps connection to the internet, they might purchase a 100 mbps and request to burst on a 1 Gig circuit. Alternatively, they may purchase a 10,000 mbps circuit, with a 1000 mbps commitment. In short, you can gain access to a faster connection and pay a lower cost than you otherwise would for fixed port. If you exceed your (lower) committed utilization rate, you “burst”. The gotcha is that the burst rate (in mbps or gbps) is often exponentially higher, so if understanding your companies actual utilization is important when deciding whether or not to burst.

Burstable circuits are available both in and outside of the datacenter, although they are more commonly found in the DC. Additionally, burstable billing is applicable to both access to the internet, as well as private line (point to point) services.

Typically, ISPs calculate usage based on a five-minute sampling and 95% usage. In other words, the top 5% of your network samples are cast aside before the ISP calculates usage cost. See the image below:

aggregate bandwidth

Image: Vixxo25/Wikipedia CC BY-SA4.0

Another advantage of burstable meaning: you won't need to scale your company's networks to support usage surges that only manifest during "busy hour" intervals. Burstable billing simplifies Poisson distribution analysis so you can engineer your networks' capacity to address typical and customary usage.

Fixed Bandwidth Billing Advantages and Disadvantages

For some businesses, fixed or flat bandwidth billing makes sense. This billing model allots a specific level of capacity to a customer each month. The customer receives dedicated bandwidth from the ISP with no extra payments for usage. A company thus can pay for what it needs and budget for a predictable monthly cost.

The downside? Should demand overwhelm capacity, packets will drop and network performance (e.g., throttling) and UX suffer. However, if most of your company's data traffic is a lower priority (viz., off-hours data backup, etc.), bandwidth management and traffic shaping can be more or less predictable. Additionally, cost has to be considered because with burstable billing, if you utilize more bandwidth than you subscribe to than you are going to pay a significantly more to burst than you otherwise would with a fixed port. Also, telco’s often deploy services on either 1 gbps infrastructure or 10 gbps infrastructure. If you are buying a gbps or less, they will often default to 1 gbps. You can ask to deploy on 10 gbps, but it will often come at a higher cost and the implementation interval can be extended. Bursting in these situations often makes less sense.

Using Burstable Bandwidth to Mitigate Against DDoS

If you're unfamiliar with distributed denial-of-service (DDoS) attacks, they occur when cybercriminals inundate servers, networks, and/or servers with a deluge of data, sabotaging customary traffic patterns. The Cisco VNI Global IP Traffic Forecast for 2016-2021 found that "the number of DDoS attacks greater than 1 GB—enough to take most organizations offline—grew 172% in 2016 and will increase 2.5-fold to 3.1 million by 2021."

"Botnets" or networks of hijacked computer devices flood a targeted server(s) in a massive automated attack. The purpose is to steal data, distribute malware, or crash company servers. In laity terms, a DDoS attack resembles an unforeseen traffic jam snarling a freeway, hindering usual data traffic from reaching its destination. DDoS "volumetric" attacks are now a leading cybersecurity worry for enterprises and SMEs alike.

Given that most DDoS attacks attempt to crash a server by inundating its bandwidth with access requests, burstable bandwidth offers a degree of flexibility when these onslaughts occur. True, no amount of bandwidth can satisfy a widespread DDoS attack such as the one that struck GitHub in 2018 when 1.35 Tbps of traffic swamped the developer platform's servers all at once. But a burstable bandwidth arrangement can mitigate DDoS attacks by having more available bandwidth.

Can Your Business Benefit from Burstable Bandwidth Billing?

Below are examples of businesses that avail from burstable bandwidth:

  • Etailers serving a sizable customer base or market promotions leading to traffic spikes

  • Streamers webcasting live streams or who have a large viewing audience

  • Hosting resellers delivering cutting-edge services to users

  • Businesses that capture or manage massive unstructured data files

  • Sites providing live data or large amounts of information

  • Entrenched blogs and news sites with customary readers and well-delineated traffic surges or "busy hour" usage

  • Online gaming sites needing fast data speeds and low latency

  • VPNs serving a large customer base

Do Providers Want You to Know About Burstable Bandwidth?

In truth, many don't. As we noted previously, "telecom providers have made the process of buying business services so time-consuming and complicated that we forget that what they sell is a simple commodity: the ability to transmit bits across a wire."

In previous decades, legacy companies such as AT&T and Verizon were regulated rate-of-return monopolies, their services, and products strictly governed by tariffs. Moreover, providers have long offered the same product to various customers at different price points—even for customers colocated in the same building.

ISPs also use "sleight of hand" marketing ploys when offering burstable bandwidth. For example, providers may claim to offer "burstable" bandwidth but charge users "by the minute" overflow fees when providing access to higher bandwidth on occasion. If your company does opt for a fixed bandwidth billing model, make sure you know how much the “overflow fees” are to ensure your company won't be gouged for the occasional overage.Also, use online speed test tools found on BroadbandNow and other websites to measure the data speeds your ISP promises versus speeds you truly receive. Note that many ISPs will initially offer bursts of high data speed when connections are made before the circuit slows to a lower, consistent speed.

No wonder organizations, even ones with dedicated IT departments, have trouble wading through billing details. A telecom proposal from a provider may include one-time fees for construction and activation along with monthly usage charges. Customers may also be subject to right-of-way access or franchise fees.

Need Help Wading Through ISP Billing Practices?

That's what we do at Lightyear. We find ISP providers—for free—and show you transparent pricing despite the complexity of your networks. We also help you cut costs on any telecom construction and negotiate your contract with your provider(s). It's a win-win for both parties; customers find their optimal solutions more quickly, allowing providers to close deals faster and improve UX.

If you want to find out more, we're always happy to help. Schedule an appointment to find out how to make telecom work better for your business!

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