What Is Network Latency, Common Causes, and Best Ways to Reduce It
Website speed is one of the most important factors when running an online business. A web page with a fast load time improves your search engine optimization (SEO) performance and user experience. To maintain good website speed, you must pay attention to network latency since it directly affects your website performance.
In this article, we will help website owners learn more about how to optimize their websites by exploring what network latency is.
We will discuss what factors influence network latency as well as how to monitor and reduce it. Furthermore, we will explain what causes high latency and elaborate on the differences between network latency, throughput, and bandwidth. After reading this article, you’ll find it easier to troubleshoot network latency issues and maintain great website performance.
What Is Network Latency?
Network latency is the time it takes for a data packet to travel from the sender to the receiver and back. A low-latency network has shorter delays in data transfer, while a high-latency network has longer ones.
What Factors Affect Network Latency
In this section, we will analyze the factors affecting network latency, from the data transmission distance to hardware and software
One of the most significant elements influencing network latency is distance. The connection speed depends on how far away the device making requests is from the web hosting server responding to those requests. The farther the distance, the longer the server latency will be.
For example, a website whose data is hosted in a data center in Albany, New York, will respond faster to requests from users in Jersey City, New Jersey, compared to those in Houston, Texas. This is because the distance between Albany and Jersey City is around 150 miles, while the distance between Albany and Houston is over 1,700 miles.
Web Page Weight
Also known as page size, web page weight refers to the overall size of a specific page. This consists of all files making up the page, including the elements like images, videos, scripts, text content, code, and style sheets. Web pages that embed content from third-party websites or have feature-heavy content like large images with a high resolution may take a longer time to load.
Transmission Software and Hardware
Hardware and software transferring data from one point to another also affect network latency. These may include transmission media like fiber optic cables, routers, and WiFi access points. Multiple devices like load balancers, firewalls, and Intrusion Prevention Systems (IPS) can also influence latency. Each component making up the network path has its own limitations. For example, optical fiber cables can transmit data over longer distances and at higher bandwidths than metal cables. However, their light and thin nature also make them more prone to damage.
Difference Between Network Latency, Throughput, and Bandwidth
Although the three are interconnected, network latency, throughput, and bandwidth have different meanings. Network latency refers to the speed at which data packets travel from the client to the server and back. Throughput is the amount of data that successfully flows through a network over a specific period. This is calculated while taking network latency into account.
On the other hand, bandwidth refers to the maximum data volume capacity that can flow through a network at any given time. The wider the band, the more data passes through the network. Therefore, the ideal situation for quick and efficient data transmission with high throughput is high bandwidth and low network latency. Low bandwidth and low latency would still be less than ideal, as even though the data is transmitted with little to no delay, the amount of data that flows through the network may be low.
What Causes High Network Latency
The following are some of the most common causes of network latency:
- Domain Name System (DNS) server errors. A web server that is not running properly can increase a network lag or prevent visitors from accessing your site. Examples of web server issues users may encounter include Error 404 and Error 500.
- Network device issues. Network devices like routers and switches experiencing low memory or high CPU usage can delay data transfer.
- Poor selection of transmission media. Companies should choose media for transmission carefully since mixing incompatible hardware and software may increase latency time.
- Multiple routers. Using several routers can create a slower network, as every time a data packet travels from one router to another, the latency increases. In addition to creating delays, this can lead to possible data packet losses.
- Suboptimal routing plan. To facilitate fast data transfers, it is important to implement proper dynamic routing. This refers to a technique that calculates possible routes data traffic could take to travel through the network before choosing the best one.
- Poor formatting of the back-end database. A poorly formatted and optimized website database can introduce latency. Some common causes for slow databases are improper index use and complicated calculations. A database not optimized for different kinds of devices can also slow down site performance.
- Terrible environmental conditions. Hurricanes, storms, or heavy rain can damage the wireless signals of satellites, thereby affecting the internet connection and creating latency issues.
- Problems on the end-user device. Like network devices, insufficient memory or RAM and high CPU usage on the end user’s device may also cause latency. Additionally, the end user’s insufficient bandwidth and outdated internet equipment can cause a slow internet connection.
How to Monitor Network Latency
In this section, we will explain different network monitoring tools you can use to test and measure network latency.
How to Test Network Latency
Here are the three main ways to check network latency and connectivity:
- Ping. Standing for Packet Inter-Network Groper, the ping command lets a network administrator verify if certain IP addresses exist and can handle requests. When you ping an IP, it sends an Internet Control Message Protocol (ICMP) request data packet to the target host over the IP network and waits for an echo reply.
- Traceroute. Using the tracert or traceroute command, network administrators can send data packets over a network and track the path they take. It also shows the number of hops they take to reach the host and the duration between hops. Additionally, this command can even check multiple paths.
- My Traceroute (MTR). MTR is a latency-testing tool that combines ping and traceroute. This network latency testing method is the most detailed one. It tells real-time information about the hops, latency, and packet loss along the network path.
You can perform the network latency testing methods above on various operating systems, including Windows, Linux, and macOS.
How to Measure Network Latency
There are two ways of measuring latency – either as the Round Trip Time or the Time to First Byte.
Round Trip Time (RTT) refers to the time a data packet takes to travel from the client to the server and back. On the other hand, Time to First Byte (TTFB) is how long it takes for the server to get the first byte of data after the client sends a request.
Network latency is measured in milliseconds. In terms of a website speed test, this speed is also often called a ping rate. The lower the ping rate, the lower the latency.
A reliable network will typically have an acceptable ping rate that ranges from 50 to 100 milliseconds. Under 50 is considered a good and low ping rate. Conversely, network latency of over 100 milliseconds falls under the high ping end of the spectrum.
How to Reduce Network Latency
After learning about network monitoring methods, it is time to learn how to fix latency problems. The following are several ways to reduce latency and improve page load time.
Use a CDN
A content delivery network (CDN) is a group of servers spread across various locations worldwide to help speed up the delivery of website content. It is also known as a content distribution network. Without a CDN, the site visitor’s browser will connect to the origin server – a computer hosting the original version of a website’s files – and request the website’s content. As mentioned before, distance affects network latency. Therefore, a visitor who is far away from the server will likely encounter a slow-loading website. Using a CDN helps to solve this problem. CDN servers cache or save the website content from the origin server. When a site visitor wants to access a website again, the browser will connect to the CDN server located closest to the visitor instead of to the origin server. The shorter distance decreases network latency and allows the web page to load faster for the user. In addition to decreasing latency, using a CDN can help distribute network traffic, prevent server overload, and improve website security. It can also reduce bandwidth consumption costs – one of the biggest web hosting expenses.
Have Fewer External HTTP Requests
Implement Pre-Fetching Techniques
One of the techniques to reduce latency is pre-fetching. When coding the site, developers can insert pre-fetching lines of code to tell the browser to load certain site resources ahead of time.
There are three main types of pre-fetching:
- DNS pre-fetching. While a user browses a page, the browser will conduct DNS lookups for links on that page. When the user later clicks on a link with DNS pre-fetching enabled, they don’t have to wait for the DNS lookup because it’s already done.
- Link pre-fetching. This lets the browsers download documents the user might visit in the near future. Say you’ve enabled pre-fetching for an image link. Once the browser finishes loading the page, it will pre-fetch the image from the image URL, thereby downloading it and storing it in the cache.
- Pre-rendering. This process renders entire pages in the background instead of just downloading the required resources for those pages. This is to provide a quick load time if the user clicks on the links to the pre-rendered pages.
Many search engines like Google use pre-fetching techniques to create a great user experience. After delivering a list of results based on the user’s search query, they will pre-fetch the pages users are most likely to visit – typically the first or second result.
Network latency is the time it takes for a data packet to travel from the client device to the server and back. Lower latency means faster data transmission and website speed. Several factors influence latency, such as distance, web page weight, and transmission software and hardware. The three main latency-testing tools are ping, traceroute, and MTR. It is measured in milliseconds, with an acceptable range between 50 to 100 milliseconds.
High latency occurs due to a variety of causes, from DNS server errors to end-user device issues. Some ways to reduce network latency include using a CDN, reducing external HTTP requests, and implementing pre-fetching techniques in the website code.
We hope this article has helped you learn more about network latency and how to reduce it to maintain fast website speed. Good luck.
Frequently Asked Questions About Network Latency
This section will answer some commonly asked questions regarding network latency.
What Is a Good Network Latency?
A good network latency depends on the kind of activity you plan to do on the web. Anything under 100 milliseconds is considered good latency for general web surfing and streaming.
For online gaming, however, you may want to aim for latency below 50 milliseconds. This is because success in gaming often relies on good internet speed and network performance.
Is Ping the Same as Latency?
Although people often use the two terms interchangeably, they are slightly different. Ping refers to the signal a computer sends to another on the same network.
On the other hand, latency is how long it takes for the ping to return to the computer that sent it out in the first place.