Many users decide to surf the Internet through VPN to make all communications more private, to avoid any regional blocking and even to bypass the censorship of a certain country. Although it is a very good decision to use a VPN, our recommendation is that you only use it when you really need it, and not always, because the use of a VPN affects the speed of the Internet, the latency of the connection and also the jitter. Next, we are going to demonstrate how the use of a VPN affects these three important parameters.
What affects the use of a VPN
When we use a VPN service, all network traffic goes from our computer to the VPN server through our Internet operator, that is, we have an additional “hop” until we reach the destination of the connection. The public IP address with which we will go to the Internet will be that of the VPN server itself, and not the one provided by the Internet operator. In this way, all traffic is forwarded through a point-to-point encrypted tunnel to the server.
That we have a forwarding of all the traffic to the server before going out to the Internet, makes the speed of our connection lower, we will also have a higher latency, especially depending on where the server is installed (geographical location), and finally , the jitter (latency variation) will also be affected. Below is a comparison of speed, latency and jitter using our Internet connection and a Surfshark VPN.
Speed
We have carried out a speed test to check the real speed of our connection, by having a 1Gbps Yoigo connection we have achieved symmetrical 940Mbps, which is expected because we will never achieve 1Gbps due to loss due to the headers of the TCP/IP packets, this speed is completely normal, we are squeezing our Internet connection to the maximum.
By connecting to the Surfshark VPN in Madrid, using the OpenVPN and UDP protocol, we have obtained a speed of symmetrical 140Mbps, far from the 940Mbps achieved if we connect directly to the Internet.
This means that when connecting to a VPN server we are going to lose the real speed of our connection. Therefore, if you are going to install a VPN client on your router to forward all the traffic from home to the VPN to protect all the connected devices, you must take into account the real speed that you are going to achieve, and carry out speed tests, because each operator behaves differently and each VPN service too.
connection latency
In the previous test we have seen that the connection latency against the masmóvil server in Madrid is 4ms when the connection is direct, however, when we go through the VPN server that is also located in Madrid, the latency increases to 7ms . Many factors influence the latency of a VPN:
- User’s Internet operator and its peering and transit.
- Location of the VPN server to which we connect.
- If the VPN server is overwhelmed by many clients, the latency will increase.
- Used VPN protocol, OpenVPN tends to have higher latency, WireGuard tends to have lower latency.
For all these reasons, the results that you obtain by connecting to the Internet directly or with a VPN change radically, but we will always have a higher latency in the connection than if we connect directly to the Internet. We recommend you read our tutorial on tricks to lower internet latency.
Jitter
The jitter is the variation of the latency of the connection of the Internet, it is one of the most important parameters and it is always recommended that it be as close to 0ms as possible. When we use a VPN, we have an additional server where all the traffic goes through, and it is possible that there will be moments of punctual collapse if there are many clients connected simultaneously, so the jitter could suddenly increase, and it is something that we must control.
In the following screenshot you can see the results of the Cloudflare speed test, which shows the ping and jitter of our direct Internet connection.
In the following screenshot you can see the ping and jitter results of our connection through the Surfshark VPN that we have previously commented on. As you can see, both the latency of our connection and the jitter have increased, however, we must bear in mind that the jitter can increase at certain times of maximum use of the VPN.
As you can see, the use of VPN affects our Internet connection, both in terms of real speed, connection latency and also Jitter. Depending on the operator, VPN service used, VPN protocol used and other parameters, we will have results that are more similar or further from our real connection, you will have to try and carry out your own tests to see the differences.
