Tech Doodles #1: Bandwidth vs. Latency & More
Illustrating Technology Concepts
Technology terms and concepts far too often seem to be unnecessarily confusing and complicated. Today we’re going to visualize bandwidth and latency and explain how they fit into other industry concepts such as SLAs, CIRs, and more!
Bandwidth vs. Latency
Bandwidth and latency are often confused with each other as they both effect the transfer of data.
Bandwidth is the level of traffic and amount of data that can be transferred between sites, users, and the internet. If a pipe doesn’t work for you, imagine moving sand with a spoon, a shovel, and a dump truck. No matter how quickly they are moving, you can only move so much sand at once. Bandwidth decides if you’re using a spoon or a dump truck to move your data.
Lower bandwidth = Less data
With latency, you can think of the news and how when they switch to a remote broadcast, the person on the other end takes 10 seconds to start talking. Slightly annoying and kind of hilarious, that is caused by high latency!
Latency is how long it takes your data to make a round trip and is effected by distance. If I am trying to access data in Milwaukee from Chicago, it’s going to be pretty fast. If I am trying to access data in Taipei it will take long because you have to make more “hops” on networks.
Going back to the sand analogy, latency is how quickly your dump truck is moving.
High latency = Longer time for data to make a roundtrip
Then, there’s Quality of Service (QoS) which refers to how a network prioritizes requests. Requests that are prioritized go faster.
For example, this can be seen with how Time Warner Cable’s network prioritizes their speed tests so it looks like your internet is faster. In reality, when you check with other speed test sites, you can see how fast your internet is when the request isn’t prioritized.
SLA vs. Non SLA Circuit
Based on that information, it’s pretty obvious you would want your network provider to have high bandwidth and low latency so you can transfer plenty of data fairly fast. However, as obvious with Time Warner Cable’s speed test trick, sometimes that isn’t always delivered on.
That’s where Service Level Agreements (or SLAs) come in. Service level agreements define the level of service you should always have and is a sort of contract to guarantee you are always getting the service you’re paying for.
Time Warner Cable, AT&T, and other typical consumer providers don’t have SLAs for their lower consumer-grade level of service, which means you might get the service you’re paying for, or you might not. Then, when your service is down, you have to call to have a technician dispatched in order for it to be fixed. You usually don’t have SLAs for typical consumer-grade WiFi, cable, or phone services.
Providers with SLAs (which include Time Warner Cable, AT&T, and Verizon at higher levels of service) guarantee a certain amount of up time and will credit you for downtime. If they are a good provider, they will already be working on fixing an issue by the time you notice it — if you even notice it before they fix it.
Committed Information Rate & Maximum Information Rate
Committed Information Rate (or CIR) is the guarantee that even though you are sharing the “pipe” with a bunch of other users, you will definitely get your share of it. At any given time, the available bandwidth should never fall below this rate.
Maximum Information Rate (or MIR) is the theoretical maximum bandwidth you can use — it is the size of the entire “pipe” you are sharing with others. This is often the rate advertised by providers, but is rarely ever achieved — even if no one else is using the service — because of bottlenecks and overheads.
TL;DR
- Bandwidth and latency are different
- High bandwidth means more data can be transferred
- Low latency means it doesn’t take long for your data to make a round trip
- Quality of service defines how a network prioritizes requests
- Service level agreements guarantee service and make the provider responsible for downtime
- Committed information rate is the guaranteed bandwidth you will get at all times
- Maximum information rate is the largest amount of bandwidth you could possibly (but likely will never) have
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About Leeward Business Advisors
Leeward Business Advisors is a Wisconsin-based corporation that provides business strategy planning, business improvement implementation, and full IT operational support. They offer world class Cloud Computing services, Cloud brokerage, Managed IT services, and a full US based Support Service Desk (called Quick Answers). Michael Polzin, CEO has 20+ years of enterprise business and technology experience gained while working at Allstate Insurance and Microsoft Corporation. Jason Klein, CTO has 15+ years delivering effective and efficient technology to Midwest companies.
