Network Latency – Causes and Best Solutions To Reduce Latency

What is network latency?

Network latency, also called “lag,” is the term for communication delays over a network. In networking, it is best to think of it as the amount of time it takes for a packet of data to travel through multiple devices, arrive at its destination, and be decoded.

A network with short delays in transmission is called a low-latency network, which is what you want. A network with long delays is called a high-latency network (not so desirable).

High-latency networks cause communication bottlenecks because they have long delays. In the worst cases, it’s like four lanes of traffic trying to merge into one. High latency makes it harder for people to talk to each other. This can be a temporary or permanent problem, depending on what’s causing the delays.

Latency is measured in milliseconds, or “ping rate” when it comes to speed tests. The performance is better when the ping rate is low. A ping rate of less than 100ms is fine, but for the best performance, you want latency to be between 30 and 40ms. We all want zero to low latency in communication, so it’s clear that this is what we want. But standard latency for a network is talked about in different ways depending on the situation, and latency problems vary from one network to the next.

How Latency Works

Let’s take a look at how latency really works and how it usually affects you as a user. Imagine you are buying something from an online store and you click “Add to Cart” on a product you like.

The chain of events that occur when you press that button are:

1. You press the “Add to Cart” button.
2. The browser identifies this as an event and initiates a request to the website’s servers. The clock for latency starts now.
3. The request travels to the site’s server with all the relevant information.
4. The site’s server acknowledges the request and the first half of the latency is completed.
5. The request gets accepted or rejected and processed.
6. The site’s server replies to the request with relevant information.
7. The request reaches your browser and the product gets added to your cart. With this, the latency cycle is completed.

The time it takes for all these events to complete is known as latency.

Causes of network latency?

1. Distance

Distance, or how far away the device sending requests is from the servers that answer those requests, is one of the main causes of network latency.

For example, network latency between cities: if a website is hosted in a data center in Trenton, New Jersey, it will respond faster to requests from users in Farmingdale, New York, which is 100 miles away, and most likely within 10-15 milliseconds. Users in Denver, Colorado, which is about 1,800 miles away, will have to wait up to 50 milliseconds longer.

Round Trip Time is the amount of time it takes for a request to reach a client device (RTT). Even though a few milliseconds might not seem like much, there are other things that can add to latency.

• There is the back and forth communication between the client and server that is needed for the connection to be made in the first place.
• The size of the page and how long it takes to load.
• Problems with the network hardware that the data passes through.

When data travels back and forth across the internet, it often has to pass through multiple Internet Exchange Points (IXPs), where routers process and route the data packets, often breaking them up into smaller packets. All of these extra things take a few milliseconds longer than RTT.

2.   Website construction

How websites are built affects how long it takes for them to load. Pages with a lot of text, big images, or content from multiple third-party sites may load more slowly because browsers have to download larger files to show them.

3.   End-user issues

Latency may seem to be caused by network problems, but sometimes RTT latency is caused by the end-user device not having enough memory or CPU cycles to respond in a reasonable amount of time.

4.   Physical issues

In a physical sense, the parts that move data from one place to another are often the cause of network latency. Routers, switches, and WiFi access points are all types of physical wiring. Also, other network devices like application load balancers, security devices, firewalls, and Intrusion Prevention Systems (IPS) can affect latency (IPS).

Latency vs bandwidth vs throughput

Latency, bandwidth, and throughput all have an equal effect on how well communications work. Even though these three things work together, they each mean something different. Imagine that data packets flow through a pipe to help you understand:

Bandwidth means how wide the pipe is. The less data can go back and forth through a pipe, the narrower it is. The more data can move through a communication band at once, the wider it is.

Latency is how fast the data packets inside the pipe travel from client to server and back. Packet latency is dependent on the physical distance that data must travel through cords, networks and the like to reach its destination.

Throughput is the volume of data that can be transferred over a specified time period.

If you have low latency and low bandwidth, you will also have low throughput. This means that, even though data packets should arrive without delay, there can still be a lot of congestion if the bandwidth is low. But if the bandwidth is high and the latency is low, then the throughput will be higher and the connection will work much better.

READ MORE:

• What Is The Difference Between Latency and Bandwidth
• What Is Ping Monitor, How Does It work?

Other types of network latency

Now that we know what global latency is and how it affects how well people can talk to each other, we can talk about two other effects of latency.

Fiber optic latency

In fiber optic networks, latency is the delay in time that light experiences as it moves through the network. Distance makes latency worse, so this must also be taken into account when figuring out latency for a fiber optic route.

Based on the speed of light (299,792,458 meters/second), there is a latency of 3.33 microseconds (0.000001 of a second) for every kilometer covered. Light travels slower in a cable which means the latency of light traveling in a fibre optic cable is around 4.9 microseconds per kilometer.

The quality of fiber optic cable is an important factor in reducing latency in a network.

VoIP latency

The speed of sound is at the heart of audio latency. In VoIP, latency is the time between when a voice packet is sent and when it arrives at its destination. A latency of 20 milliseconds is normal for VoIP calls, and a latency of up to 150 milliseconds is so small that it is fine. But if you go above that, the quality starts to get worse. At 300 ms or more, it can no longer be tolerated.

High latency in VoIP can severely affect call quality, resulting in:

• Slow and interrupted phone conversations
• Overlapping noises, with one speaker interrupting the other
• Echo
• Disturbed synchronization between voice and other data types, especially during video conferencing

Reasons behind VoIP latency and how to fix it:

Insufficient bandwidth – with a slow internet connection, insufficient bandwidth means that data packets take more time reach their destination, and often arrive in the wrong order.

Firewall blocking traffic – to prevent bottlenecks, always allow clearance for your VoIP applications within your firewall software.

Wrong codecs – codecs encode voice signals into digital data ready to be transmitted. This is often an issue that your provider needs to solve, however some VoIP apps allow you to tweak codecs.

Outdated hardware – Sometimes the mix of old hardware and new software can cause latency problems. Changing your telephone adaptor or other VoIP-specific software can help. Even your headset can cause latency.

Signal conversion – If your system is converting your signal to or from analog and digital, this could cause latency.

Best practices for monitoring and improving network latency

In the business world, where time is so valuable, when your network slows down, it can be a big problem. As your network grows, having more connections means more places where things can go wrong or take longer than they should.

As more and more businesses connect to cloud servers, use more apps, and grow to accommodate remote workers and more branch offices, this can cause more problems.

Everyone in business has dealt with latency at some point, and it can be a big problem for deadlines, expected results, and eventually return on investment (ROI). This is where full monitoring and troubleshooting of the network comes in handy. Monitoring and troubleshooting a network can quickly and accurately find the root causes of latency and put in place solutions to fix the problem or make it better.

You need to know how to calculate and measure network latency before you can do anything to fix it. If you know your latency, you’ll be much better able to figure out what’s wrong.

How to Test Network Latency

You can use ping or traceroute to test network latency, but a more accurate way is to use network monitoring and performance managers to test and check latency.

Keeping a network that works well is important for a business to run well. Problems with a network can get worse if they are not managed well.

How to Measure Network Latency

Tools for monitoring and managing a network will automatically get this information, but here’s how to do it by hand. When you type in the tracert command, you’ll see a list of all the routers on the path to that website address, followed by a time measurement in milliseconds (ms). When you add up all the measurements, you get the latency between your computer and the website in question.

Latency can either be measured as the Round Trip Time (RTT) or the Time to First Byte (TTFB):

• RTT –  the amount of time it takes a packet to get from the client to the server and back.
• TTFB  – the amount of time it takes for the server to receive the first byte of data when the client sends a request.

How to Reduce Network Latency

One easy way to fix network latency is to make sure that other people on your network aren’t taking up too much of your bandwidth or making your latency worse by downloading or streaming too much. Then, check the performance of the applications to see if any of them are acting strangely and putting pressure on the network.

By putting together the endpoints that talk to each other most often, subnetting is another way to reduce latency across your network.

You could also use traffic shaping and bandwidth allocation to improve latency in the parts of your network that are most important to your business.

Lastly, you can use a load balancer to help send traffic to parts of the network that can handle more activity.

How to Fix Problems with Network Latency

Fixing problems on a large network by hand can be hard, which shows again how important network monitoring and problem-solving tools are.

To find out if a problem is caused by a specific device on your network, you can disconnect computers or network devices and restart them all. You’ll have to make sure that network monitoring is set up.

If you’ve checked all your local devices and are still having latency problems, the problem could be at the place you’re trying to connect to.

What Tools Help Improve Network Latency?

Network monitoring and troubleshooting tools are the best way to keep an eye on latency as well as packet loss and jitter, which are two of the most annoying network problems. Usually, you can set network standards for latency and set up alerts when the network latency goes above this baseline by a certain amount.

You can compare data from different metrics with the help of network monitoring tools. This can help you find performance problems, such as slow applications or errors that cause network latency.

A network mapping tool can also help you figure out where in the network latency problems are happening. This makes it easier to find and fix problems.

Certain traceroute tools keep track of how packets move across an IP network, including how many “hops” it took, the roundtrip time, the best time (in milliseconds), and the IP addresses and countries it went through.

By making your network faster and cutting down on latency, your business processes will also become more efficient and effective.

Examples of Latency

High latency can hurt the performance of your network and make it much harder for your application to talk to users quickly. A content delivery network makes it easy for customers to get their content to their users as quickly as possible. The network delay between the user and the application is cut down by a lot with these delivery channels.

On a Windows or Mac computer, you can use the command prompt to check the network latency of any website. To do this, type the website’s web address or IP address into the prompt. Here’s an example of the Windows command prompt:

C:Usersusername>ping www.google.com Pinging www.google.com [172.217.19.4] with 32 bytes of data: Reply from 172.217.19.4: bytes=32 time=47ms TTL=52 Reply from 172.217.19.4: bytes=32 time=45ms TTL=52 Reply from 172.217.19.4: bytes=32 time=47ms TTL=52 Reply from 172.217.19.4: bytes=32 time=43ms TTL=52 Ping statistics for 172.217.19.4: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 43ms, Maximum = 47ms, Average = 45ms

Key Takeaways

• Latency is the amount of time it takes for a data packet to travel from the sender to the receiver and back to the sender.
• High latency can slow down a network by causing bottlenecks.
• If you use a Content Delivery Network (CDN) and a private network backbone to move data, you can make your web apps less latent.