In tech speak, Round-Trip Time (RTT) refers to the exact length of time, to the closest millisecond, that it takes for a browser to send a request to a server and receive an answer in response.
Frequently tested using a technique called a “ping,” RTT is a measure of latency that’s a key performance indicator for web applications which arguably matters a lot more (even if it’s discussed a lot less) than bandwidth speeds.
A good RTT score means faster page load times and lower network latency. It means faster complete request loops when it comes to receiving all the objects that need to be downloaded — whether that’s HTML, images, on-page scripts, and more — in order for a web page to be populated. Because objects have to be requested in different request loops, rather than altogether in one go, RTT is a measure that matters a whole lot when it comes to how quickly a particular page will load.
The factors that affect RTT
Several factors affect RTT. Two of the main ones are the distance between the user and the web server they are accessing, and the number of intermediate points the request has to travel through as a connection is made.
When it comes to bandwidth (or the majority of other benchmarks people use to score technologies), the higher number is the best number. 25 Mbps is a better bandwidth speed than 10 Mbps, for example.
Because RTT is, in essence, a relay race, the lower score is the better one. It means that each trip to the server and back again was concluded in the shortest amount of time possible.
Introducing Content Delivery Networks
To aid with this process, you can use Content Delivery Networks (CDNs.) A CDN is a group of highly distributed servers or Points of Presence (PoP) that work together in order to ensure the rapid delivery of content online.
If there is no CDN in play, servers have to respond to every single request from end users. This can mean heavy traffic, which can cause slowdowns. Using a CDN, the load is shared across multiple servers, enabling the fast loading of online assets ranging from images to video. It reduces the physical distance that exists between the web server and the end user, with users accessing a copy of the data that’s near to them, rather than everyone having to scramble to access one server. As mentioned, this physical distance is one of the key factors that causes poor RTT speeds.
CDNs can also employ other smart tricks to improve RTT. For instance, they can use methods like file compression to reduce the size of files that have to be transferred, meaning faster loading times. During times of high traffic, CDNs may also route requests via backup servers that have lower network congestion. This, again, can speed up server response time in a way that benefits RTT.
CDNs are a game changer
CDNs are exceptionally valuable tools for a number of reasons. In an age of high bandwidth speeds and 5G technology, users are increasingly accustomed to high speed internet usage. A web page or entire website that loads slowly is off-putting to users. This may mean a higher bounce rate (a higher bounce rate means that visitors come to your site to view one page and then leave again, rather than checking out the rest of the site) and shorter term visitors.
On the flipside, a page that loads rapidly results in a better user experience for visitors. A CDN can cut an RTT in half, decreasing it by 50% or more. This improvement will result in a more positive visiting experience for users.
Search engines also factor in website speed as part of the calculus they engaged in when it comes to ranking. Google, the most widely used search engine in the western world, has incorporated speed as a ranking factor for desktop searches since 2010, and for mobile searches since 2018.
Having a sluggish website could therefore not only mean that visitors leave more rapidly without checking out the other links on your page; they may never even visit in the first place at all.
Don’t waste time, act now
Here in 2021, you simply can’t afford to have a website that loads sluggishly. This might have been non-ideal, but not a killer, in previous years. However, in today’s competitive internet market, a slow RTT just isn’t going to cut it.
Fortunately, there are plenty of CDN providers who can help out in this capacity. Choose the right one for CDN onboarding and you can start to reap the rewards of this technology. It is one of the smartest moves you can make when it comes to improving website performance for the benefit of your users — and, ultimately, yourself.