VoIP Requirements

Before signing up for business VoIP service we recommend that businesses run through the following VoIP requirements list. By following the information in this guide your business will have reduced the chance of audio related issues with VoIP.

In this article we highlight the three main VoIP requirement areas that should be carefully considered, these being the quality of your current Internet connection, the hardware required and the type of business VoIP service you need.

1: Internet Service

It is of paramount importance that the Internet connection at your business is of a high enough quality and speed in order to support business VoIP service. Before we get to our Internet requirements list, some background information on bandwidth may be useful.

How Much Bandwidth Does VoIP Use ?

A common question we get from potential customers is how much bandwidth does VoIP use? A good rule of thumb is to assume 90Kbits/second per phone call. Knowing this magic number will help you determine how to calculate VoIP bandwidth requirements.

How to Calculate VoIP Bandwidth

In order to calculate VoIP bandwidth requirements for your business determine how many concurrent calls you will need at any one time for your business and simply multiply that by the VoIP bandwidth per call stated above.

For example, let's assume you must support a maximum of 5 concurrent calls. You will need to ensure you have at least 450Kbits/second (i.e. 90Kbits/second * 5 calls) bandwidth available for phone calls. This is approximately 0.5Mbits/second and really is a relatively small bandwidth requirement. Most Internet providers state this in terms of speed, for example, perhaps you have an Internet speed tier of 5Mbits/second.

Another important point to make here is that most Internet service offerings are asymmetrical in that they have different speeds for up-link and down-link. The VoIP bandwidth calculated above is required for both up-link and down-link directions.

Internet service has improved significantly over the last 5 years so the required VoIP bandwidth really should not be a factor. Just keep in mind that you will likely have many other devices utilizing your Internet bandwidth at the same time.

Internet Requirements List

Now that you have this background information on bandwidth, it's time to review some Internet requirements:

  • VoIP Bandwidth

Use the information detailed above to determine your VoIP bandwidth requirement. Verify your current Internet plan has high enough speeds.

  • Consistency of Service

Is your Internet connection stable or does it occasionally have problems where the speed drops for no apparent reason? If it has issues you will likely experience some audio problems during these times. A consistently good and stable Internet is required.

  • Low Packet Loss, Latency and Jitter

Similar to consistency of service, in order to maintain high quality audio calls there should be minimal packet loss errors and low latency and jitter. This will ensure that audio packets to and from our servers will reach your phones error-free and on-time.

  • Run a VoIP test

Complete the form below and we will provide you with access to our VoIP test which will determine if your Internet service is good enough for VoIP. It will also calculate a MOS score which is a parameter used to estimate audio quality for VoIP calls.

2: Hardware

What Hardware do you need for VoIP ?

The hardware you need for VoIP is relatively small for a hosted VoIP service since all of the servers are hosted in the cloud. All you need are phones and these can be purchased from Cabertel and are pre-configured and shipped to your place of business.

An Internet modem and router are of course required and some recommendations are detailed below for completeness.

  • Phones

The phones connect to your Internet and are pre-configured with your account credentials so they authenticate with our PBX servers. Cabertel has a wide choice of IP Phones that can be purchased, ranging from low cost work horse type phones to high-end executive models. We also offer adapters that can be used with existing traditional analog or cordless phones. Hard-wired phones are always recommended over wireless for security and audio quality. Make sure your business has Ethernet jacks (RJ-45) access at each station or cubicle. Most phones have built-in Ethernet switches, meaning you can connect a PC or laptop to your phone and share the Ethernet connection.

  • Modem

The modem is the device that provides your business with access to the Internet and it is typically provided by your Internet provider. Keep in mind that usually the Internet provider charges you a hardware rental fee for this device and it can range from $7 to $15 per month. Did you know that you can often buy this device yourself for around $50 and remove the rental fee? Let Cabertel know if this is of interest and we will suggest a suitable device based on your Internet provider's service type (i.e. is it cable, DSL etc). Another advantage of this approach is that you will likely have less issues since the Internet provider will typically give you a device that has a modem, router and WiFi all built-in and these can sometimes be problematic for VoIP, depending on the make and model of the device being used.

  • Router

Though not a hard requirement, we strongly recommend using a router, for security reasons. This adds a firewall and Network Address Translation (NAT) between the Internet and your phones and other devices inside your business. For VoIP, it is best to have only one router in the path from your phones to the Internet. If you have more than one (i.e. double-NAT condition) it can sometimes cause problems for audio packets and their routing to and from your phones. Some people don't realize this but let's say you use a Sonicwall router for your business but your cable modem also has a router built-in, well that's potentially a double-NAT condition. Also make sure all SIP ALG settings are disabled in your router. Cabertel can offer support here based on the make and model of your router. If your bandwidth is low it may be advisable to turn on Quality of Service (QoS) in your router so that there is always enough bandwidth available for your phone calls, even under heavy Internet usage conditions. More information can be found in our VoIP Best Practices guide.

  • Switches

Ethernet switches may be required if you have multiple phones and devices in your business. Switches are used to expand your Local Area Network (LAN) when you are utilizing all of the Ethernet connectors (RJ-45) on your router.

Read our VoIP setup guide for a more detailed view on setting up VoIP in your office.

3: Business VoIP Service

There are a few types of business VoIP service in the market place, ranging from cloud PBX based service (also known as hosted VoIP) to IP PBX hardware and software solutions that are installed on-premise at your business.

The Cabertel service is cloud based, meaning all of our servers are hosted in secure, geo-redundant data centers. The main advantage to this is that you simply connect your phones to the Internet and you are making and receiving calls. No hardware or software to maintain.

Though not strict requirements, the points below can be used to determine your needs for business phone service.

  • Reliability and Security

Make sure your expectations are met regarding reliability and security of your VoIP service provider. Do they have redundancy architected into its system? Is it secure? These questions are important to ask any provider, including Cabertel.

  • Phone Numbers

List all of your phone numbers and verify they can all be ported over to VoIP.

  • Features

Determine any feature requirements your business may have. For example do you need an auto attendant? What about ring groups, call recording and other features.

  • Pricing

Compare pricing with other VoIP providers and make sure you are not paying for features you will never use. Also check all of the added fees like taxes and regulatory fees.


We hope this VoIP requirements guide has been useful. As always, if you have any questions at all reach out to us either by phone or using the contact form below.

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