Smart DNS Proxy l December 14, 2017

What is DNS Latency and Why Should You Care?

Latency is an integral part of today's interconnected world. It's the one that determines the efficiency of the real-time exchange of information. In simpler terms, DNS latency is the amount of time data can reach a particular destination and come back. The lower the latency, the better it is for you.

And it's up to the packet of information on how fast it will go from one point to another point.  The primary cause of why latency happens is physics. Everything travels below or at the speed of light. This includes the tiny bits of information that travel from the source to the receiver. Physical teleportation is still the stuff of science fiction. If not, then there would be no latency as everything will happen instantaneously.

Put it this way. When you drive to a particular destination, you take up time. Let's say you're going to fetch your child from school. You pass through a series of roads before you reach your destination. That's the same process that happens when you click on something on the internet. You send a request, and that request is the car in our analogy.

The request travels through a tunnel, like how a car travels through the road. Take note that DNS and VPNs go through a tunnel. This tunnel then lets a person to gain access to something that isn't available in their region. Therefore, the tunnel acts as the passageway or the means for the request to happen.

Reaching the destination and picking up your child from school is synonymous as to how data is accessed. After that, the user still needs to receive the data. In this case, the user is the house. The moment you and your child reach your house is the moment the request process is finished.

Latency vs. Bandwidth

Bandwidth is the range of frequencies used to transmit data. It is measured in megabits per second (Mbps). Most internet service providers only advertise their plan's bandwidth. They also misleadingly refer to it as your connection's speed.

When in fact, having high bandwidth won't always result in fast internet speeds. It’s because there are a lot of things that affect it. The cables, routers, and amplifiers present in the network link are some of these things.

Meanwhile, latency is the delay that you experience when you click something, and you wait for it to show up. You send a request when you click a certain webpage or do something else online. The request then travels to the server and then comes back again to you. Your latency is measured in milliseconds (ms). Some people also refer to latency as "ping." The usual latency in standard internet plans is 150 to 200 ms, which is not that good. The higher this number is, the more delayed your requests come to you. This is a big hassle to gamers and businesses that rely on real-time communication.

If you're a gamer, it would be more important for you to prioritize having low latency instead of high bandwidth. It doesn't matter much if your bandwidth is not that good. As long as your latency is low, you're less likely to experience lags.

The bandwidth merely acts like the one that enables the exchange of data. Meanwhile, latency deals with the real-time exchange of information. It also happens that this is the most important thing when playing an online game.

Having a good bandwidth and bad latency results to longer loading times. But once the initial connection pushes through, the entire page would load instantly. If it’s the other way around and you have a not-so-good bandwidth but good latency, loading times would still be fast. However, the web page loads slowly.

How does DNS Latency happen?

DNS Latency happens because of four components. These components are the ones that constitute the delay you experience. It might be that you’re playing a game, communicating with someone else, or browsing the net. Whichever the case is, those activities go through the same process.

1. Processing

This is the amount of time it takes your device to process information. In simpler terms, this is when the data from the destination is accessed and analyzed. And it’s up to your network devices on how they’re going to handle this data. It’s like saying how the data will get to the next stop, for it to reach you.

2. Queuing

You deal with a lot of packets when using the internet. It might either be files that are currently downloaded, emails sending, or websites loading. These activities have their packets. And each needs to be dealt with, one packet at a time. For your request to be processed, it first needs to wait in line. Queuing algorithms are the ones that handle which packet goes first and which one waits.

3. Transmission

Transmission delay is the amount of time it takes to gain access to the data and put it in the network link. It’s another way of saying how long it takes for the already accessed data to be sent on your way. To ensure you receive data as soon as possible, it’s important that you have a high bandwidth capacity.

4. Propagation

Then there's the element of distance. The distance between the two points where data is accessed and is originally located is another one which makes up the latency. But what makes this different from the other components, is that it cannot be reduced. You can't improve the propagation speed of data because it needs to travel.

Unlike the other contributors, you cannot reduce the latency with better technology. If a DNS user from Hambantota, Sri Lanka accesses a server from Los Angeles, U.S.A., latency would still be evident. This is because of the disparity in the distance. It doesn't matter if the technology is better at one point as distance still separates them apart.

Usual Causes of High Latency

1. DNS Server Location

The location of the DNS server you're accessing plays a huge role in your latency. The farther the server is to your place, the higher the latency gets. But this is not always the case as centralized DNS servers' latency isn't affected by the distance from the user. Transit links also vary from one server to another. Latency will be lower if the transit links are equipped with up-to-date technology

2. Wireless networks

Wireless networks have higher latency compared to wired networks. This happens because the transfer of data doesn't go through fixed lines. Instead, it goes through Wi-Fi routers or satellite dishes. These devices' efficiency also depends on the location where they're placed.

3. Malicious DNS Traffic

Malicious DNS traffic can also cause high latency. It's because the DNS server will work double time in processing it. PRSD attacks are the most common type of malicious traffic. When this happens, it causes a lot of malware and botnet queries which cause high recursion rates. These consume and waste a lot of CPU cycles on the server.

4. Under-scaling of DNS Server

Proper scaling of the DNS infrastructure is important. Because if it’s not scaled correctly, chances are is that it will use too much CPU power. When this happens, it will impact the latency and cause it to increase. The more the CPU is utilized, the higher your latency gets.

Monitoring Your DNS Latency

You can monitor your DNS Latency by deploying probes in your network. The probes are the ones that enable you to keep track of the queries. And it’s in knowing the queries that you’re able to measure the response time of your online activities.


There are also many network management systems (NMS) that provide you with visual presentations. Take note that when using an NMS, make sure you set the threshold at 20ms. This is the recommended threshold as it wouldn’t negatively impact your latency.

So Why Should You Care?

1. Real-time Communication

Latency causes the delay in your online activities. And one of the most common things you do on the internet is communicating with other people. Live video chats have become a staple form of communication today. But if you have high latency, you'll experience overlaps with the transmitted audio and video.

2. Gaming Responsiveness

The internet is also a haven for leisure time, as people use it to play online games. Unfortunately, you can’t play properly if you’ve got high latency. The delay in your character’s movements would be too much to take in — you better quit playing. But that won’t be a problem if you have low latency because your commands would be followed by your character instantly.

3. Latency’s Relation with Internet Speed

Your internet speed doesn’t just rely on your bandwidth. A 30 Mbps satellite connection wouldn't guarantee you a fast internet connection. This is because wireless networks such as satellite connections have higher latency.


With all of these said, you can see that DNS latency revolves around the whole concept of user experience (UX). The lower the latency is, the better. Just be sure to pair it up with a high-speed internet. This way, you'll have the best online browsing/gaming/communicating experience.