How does internet speed impact a VoIP phone system?

Whenever out team starts a new project with our clients, they’re usually concerned that their new VoIP phone system may not be compatible with their current internet service because they assume the VoIP system will require lots of bandwidth.

This is due to the fact that most people are not aware how much bandwidth is required to run a hosted VoIP phone system nor do they understand the difference between internet speed and bandwidth and how each of these affect a VoIP call.

Can Internet speed or bandwidth have an impact on a VoIP telephone system? The Yes, is the short answer!  It's important that we first understand what the difference is between “internet speed” and bandwidth.

Most Internet Service Providers (ISP’s) and IT providers use the two terms interchangeably, so it is easy for the average VoIP user to get confused.  In fact, when you go online and perform a speed test on popular sites such as you are testing your bandwidth and not the actual speed of the internet.

Picture your internet service as a highway. On this imaginary highway, there is only one-lane with a speed of 50 mph.  You send out a driver carrying packages and the driver makes it to the destination with no issues. The packages are transferred and make it on time to the destination. Everything ran smoothly and as expected and you continue sending your driver down this highway.

During the next month you have more packages to deliver and you decide to send out two drivers, not one, with packages at the same time on this one-lane highway. Surprisingly, you receive a report that one of the drivers was late getting to their destination due to traffic and tried to find an alternate highway which lead to loss of packages. What happened?

While everything started off okay, given that both drivers left the site at the same time and merged onto the highway; however, the second driver was stuck behind the first driver going at the same exact speed. Although he tried, he couldn’t pass the first driver because there it's a 1-lane highway. The second driver started encountering delays (in the telecom/IT world that's known as latency) while driving down the one-lane highway. Fearing that he will continue to encounter delays he then tried to find an alternate route which lead to him losing some packages also known as packets along the way. When the driver finally arrived to the destination he was late and missing packages.

If you haven’t already guessed the one-lane highway is your bandwidth and to solve this problem with our drivers we would need to upgrade our bandwidth from a one-lane highway to a two-lane highway or even a four-lane highway if want to make sure we don’t run into this issue in the future.

How do internet speeds & bandwidth relate to highway driving?

The internet speed is speed limit of a highway and bandwidth is the amount of cars and packages that fit on the road.  As bandwidth increases, so do the lanes of the highway.  When you have more bandwidth you are able to transfer more information.

In our highway analogy we discussed some terms that may be helpful to know along with some other important terms when talking about your Internet service.

·         Ping – A test for determining latency.

·         Latency – A delay in packet delivery.

·         Packet – Internet Packages in our analogy. This is the unit of data that is routed between an original location and a destination on the Internet.

·         Round Trip Time (RTT) – The length of time it takes for a signal to be sent plus the length of time it takes for an acknowledgment of that signal to be received.

·         Bandwidth – Capacity or lanes on the highway, is the minimum capacity (in bits per second) across all network links between two connections.

VoIP phone systems are impacted by local networks as well

VoIP phone systems run entirely over the Internet. VoIP is dependent on both the local and wide area network. If voice quality problems occur, either for brief periods or longer durations the problem can often be the direct result of the network connection. This would include your ISP or some other component between you and the party that you are talking with.

When Liberty Communications deploys our VoIP services it is considered "best practices" to always separate the computer network from the VoIP or voice network.  Both of these connections --the voice and the data-- in your office should be hard wired (not wireless) and physically separated from the office jack all the way back to your IT closet.  We do not recommend using a wireless internet service, or connecting the phones through wifi.

The required device that connects your computers and network equipment to the Internet is called a router.  Liberty Communications knows how to match the right router with the number of phones you will have in your office and will be compatible with VoIP services.  A router that is used with VoIP should be able to handle multiple Internet connections for two different providers.  It's always a smart idea to have a secondary backup internet connection.

VoIP Internet Bandwidth Requirements

There are two types of bandwidth: upload and download bandwidth. The Upload Bandwidth is the amount of data you can send to the Internet and download bandwidth is the amount of data you can receive from the Internet.

In most cases, a normal VoIP telephone call will use up 100 Kbps (kilobits per second).

How much bandwidth you require in your office would be based on how many concurrent (or simultaneous) calls you would have at any given time.  Liberty Communications has put together a simple chart to show concurrent calls and what Internet package we would recommend by your Internet Service Provider.

Number of Concurrent Calls

 Recommended Speeds


3 MBps Up and Down


3 MBps Up and Down


5 MBps Up and Down


5-10 MBps Up and Down




I’ve partnered with Liberty since its inception and its owners prior to that.  They provide support on our phone system on an on-going basis.  They’ve always been dependable and reliable.  Liberty also has a unique empathy for us as their client.  This uncanny empathy means they’re always focused on our needs. I have also contracted Liberty for electrical and data...
Robert Marchetti

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