VPN Frequently Asked Questions
- What is a VPN?
- How does a VPN work?
- Why is my VPN slow?
- How can I get better speeds for my remote uses?
A Virtual Private Network, or VPN, is a connection between two or more end points on the internet.
We call it virtual because it is not the actual physical wire connecting two locations.
Instead, special equipment at a location establishes a logical connection between itself and similar equipment at other locations. There is no physical wire connecting each of the locations.
A VPN is not limited by the type of internet connection you may have in your office. In theory, it works over any type of connection.
Everything from a simple dial-up internet connection to the fastest fiber connections.
Needless to say however, a VPN connection over a dial-up service will be very slow compared to a VPN connection over a 100Mbps fiber service.
The VPN service is created and managed by the router equipment you install on your internet service. Not all equipment is capable of these advanced features. SwitchWorks can help you select the correct equipment for your needs. Once in place, every site that has this equipment installed can establish a virtual connection between all other locations configured to accept connections, in so doing extending all, or portions of your internal office network to those remote locations.
As we mentioned above, a VPN is a virtual connection which can exist over any type of internet connection. Typically, many people use a basic Internet service like aDSL High Speed internet. This is a great choice generally as it provides good performance at a fair price. Many factors can affect the best choice for your company and application.
Let’s start with how aDSL is designed. aDSL is an acronym for Asymmetrical Digital Subscriber Loop. As the name suggests, the service is "Asymmetrical" meaning it has different speeds in each direction. It was designed to provide high speed for downloading information but only allow for minimal speed uploading. There are technical reasons but we wont go into it here. It’s not important to VPN’s.
What is important to know is that aDSL provides high speed one way, and low speed the other. Most importantly, low speed out to the internet.
Here’s where the hardship begins. When well intentioned, but lesser experienced people build VPNs, they order DSL. For example, our typical business aDSL is 6Mbps x 800kbps. They will order one at their head office. They will order them at their remote offices as well. They connect up everything and find they only get speeds of 500-600kbps across their VPN. They get frustrated because they are not seeing 6Mbbps x 6Mbps.
This is where your high school math comes in. The rule of "Lowest Common Denominator". What does that mean, you may ask?
Well when you take two offices and connect them across a VPN that runs over aDSL, it can only send data from one office to the other at the upload speed, 800kbps max. Similarly, the remote office can only send information back to you, upload, at 800kbps max. It doesn’t matter that each site can download at 6Mbps, they can only receive data as fast as the other side can send or upload it.
So at the end of the day, the VPN connection is limited by the lowest, not the highest speeds your connections support. in the case of aDSL, the BEST speed you can hope to see is 800kbps x 800kbps.
In fact it will be slower than this because of other issues including:
- the overhead to manage the VPN which introduces delay and takes up some of your bandwidth;
- standard DSL issues which often limit the speeds of a DSL connection. Few customers ever see the full 800kbps.
What can I do to fix this problem? If we didn’t have a solution for you, we wouldn’t make you aware of the problem. Give us a call if you have a VPN and you need it to go fast!