VoIP Requirements

Business VoIP Requirements Checklist

Introducing VOIP

Before businesses purchase a voice over IP or a IP PBX server in their offices, there are several items that must be addressed. When switching from a traditional phone provider to voice over IP, it requires a lot of bandwidth, a different router and switch, as well as a backup battery in order to protect from power outages.

The voice over IP requirements that are mentioned in this article are:

  • Bandwidth- The first step in finding out how much your business will need for voice over IP in the office.
  • Router- If one chooses a low quality or cheap router, it will affect the quality of the calls they will make.
  • QoS (Quality of Service)- Businesses need to figure out if voice traffic will be apart from the internet or if they will be combined on one network.
  • Voice over IP Equipment- These includes digital telephones, SIP phones, microphones and adapters.
  • Power Failure- Voice over Internet Protocol does not start up if the power goes out. There should always be a backup battery system as well as an Ethernet adapter if possible.

How much bandwidth is required?

Voice over Internet Protocol requires a dedicated amount of bandwidth in keeping conversations of a clear and uninterrupted quality. Bandwidth is how much the internet is able to send or receive in a certain amount of time. The first step to figuring out how much bandwidth you currently have is to do a speed test to find out how fast you are sending and receiving data. This should be done when the computer is hardwired to the modem, rather than doing it wirelessly (wifi). This will ensure more accurate results. The speed test should be done several times throughout the day to average the amount of bandwidth from the connection. The unit of measurement is in Kilobits/second or Kbps.

Businesses need to have broadband internet in order to efficiently use voice over Internet Protocol. The usual DSL connection will have a rating of about 600 kbps for uploading and a 5000kbps for downloading data. Businesses should be aware that uploading data is always smaller than downloading data, since this is what limits you when using voice over IP.

The next step will be to find out how many users are going to be on the phone concurrently. An example would be when having ten users talking on the phone; the bandwidth should be at least ten times as much as having a single person on the phone. There is a chart below that will help in the calculations of how many users are able to be on the phone:

It is wise to ask your provider what CODECS they have since there is usually a give and take quality in between voice quality and using bandwidth…

G711 CODEC is the Full Quality Audio - Each concurrent call uses 87 kbps
G729 CODEC is a Compressed Audio - Each concurrent call uses 33kbps

Figuring out this calculation for a DSL connection is:

The DSL connection : 600 kbps uploading/ 5000kbps downloading
G711 CODEC- 600 kbps/87kbps = 6 calls concurrently
G729 CODEC- 600 kbps/ 33kbps= 18 calls concurrently

As you should see the uploading bandwidth in the calculation is limiting the voice over IP. It is not a good idea to max out the limit of bandwidth on your connection for cable and DSL since there is no guarantee how much they will be able to put out. If the connection decreases in bandwidth during parts of the day, the voice quality will be affected. Other items that will affect voice over Internet Protocol is the amount of packets that are lost.


The router connects all of the computers and equipment together to connect to the internet. The router is often overlooked since it can have a detrimental impact on the implementing the voice over IP system. There are many types of routers out there; several are fairly inexpensive (around $40), and some can cost thousands. Having poor quality from a router will cause the voice over IP system to not work at its fullest potential.

A powerful router will be able to handle the amount of phones that your business requires to operate on, and it should be able to work perfectly with the equipment. The voice over IP provider will be able to tell you what types of routers are good to work with. It is recommended to ensure the router will work with voice over IP as well. The following list will identify which router is the best for your voice over IP system:

  • What is the number of phones that you will be connecting? The more phones the better quality the router has to be. Cheap $60 routers will get the business phone system no where with an office with many phone lines.
  • Does the voice over IP system need a separate connection to the internet? If they do not, a router with QoS settings will be able to prioritize the different types of traffic is a requirement. If there is not a Quality of Service, the business will receive poor telephone quality.
  • Any other things that the router needs to do? Some routers need to connect to a vpn connection which allows wireless users to connect or do other items.
  • Make sure the modem can bridge with the router. If they aren’t bridged, there will be issues in the installation process.
  • One router or gateway should be used on a network at any given time since this will cause problems for Internet Protocol phones when they attempt to use the gateway.
  • Make sure the router is compatible with the Compatibility Guide to Routers.

It is wise to talk to your service provider since they will know what routers are the best to use with voice over IP phones.

QoS (Quality of Service)

The quality of the call is a function of the internet and the network. Delays and congestion on the network are unavoidable since information travels over the regular internet when the other types are avoidable. Designing the network well will result in a stable implementation of a voice over IP system.

QoS is the ability for a router to rate voice traffic differently from other internet traffic on the network. Voice over Internet Protocol uses a real time protocol, so if any information is delayed there will be a drop in quality or a dropped call. Some things to look out for when experiencing congestion are incoherent voices, calls that are dropped, and echoing. While you are setting the voice over IP up in the business there are several ways to take care of audio traffic. Customers may report excellent quality of the call, especially if there are only one or two phones in the business, others may complain of the quality if the QoS is enabled since some routers are poor at this. The most reliable method of doing voice over IP is by having its own connection to the internet. The equipment is the only thing using the internet and not normal internet users. Here are different ways to do QoS:

  • No Quality of Service- This is where both types of traffic (voice and regular) share one internet connection. There is no prioritizing who gets the most bandwidth and quality will be poor sometimes due to not enough bandwidth for the voice traffic. Customers will experience some quality issues when talking to the business and some may not experience poor quality issues. It all depends on the time that people are using the internet when a person is on the phone at the same time. Many connections upload faster which results in having people not hear you, because the upload speed is slower by another user on the system.
  • QoS Router Enabled- Both types of traffic are sharing the connection again, but routers are able to figure out which traffic is voice and which is for regular users. This can ensure higher quality for the voice traffic when a user needs to make or take a phone call. Some routers are able to only figure out how to prioritize uploading but the downloading part will not be able to be prioritized. Employees who are downloading will create a poor voice quality when an employee is on the phone. There may be dropped calls due to excessive downloading. There are providers who can prioritize downloading speeds using these two methods (COS or TOS) which will create a better quality of service. Many customers see an increase in quality in the voice over internet protocol since many connections are limited by the uploading speeds and who have the download speeds freed up.
  • Separate Traffic- The two types of traffic (voice and regular) are split up onto two different networks and connections to the internet. This is imperative if larger businesses with more than five employees. Voice traffic will be on a dedicated voice internet connection and the regular internet users on a completely separate connection. There will not be any need to prioritize traffic since both traffics are on two completely separate connections. This is the only way to dedicate clear voice quality and is highly recommended whenever it is possible for businesses to do so.

The type of router depends on how much speed you need and what you need to dedicate that speed to; if you are using more internet than voice calls or vice versa. Many businesses can operate flawlessly without using QoS, but larger companies find that they are unable to live without it.

Voice over IP phones and the equipment

There are many types of phones and equipment when going the voice over IP route for your business. It is wise to ask your service provider for recommendations when implementing the system.

  • Digital Phones- They look just like any other business multi line phone but they can connect to the internet using a cable.
  • SIP Phones- This is a soft phone that uses software that runs on the computer and it looks like a real phone. This requires the usage of a headset that plugs into the computer or notebook in order to dial and take calls.
  • Wireless Telephones- The wireless telephone looks like a mobile phone but it connects to the wireless router in your office.
  • ATA- An Analog telephone adapter is a tiny box that connects to the router and plugs into an analog phone so you can work with VOIP. Analog telephone adapters are cheap instead of purchasing the digital IP phones, and are easily mobile.

Back Up Methods

Many businesses do not think of having a backup battery when the power goes out. The VOIP system will not work if the power goes out unless you have a back up battery or have the VOIP system connected to an Ethernet cable so the business an still send and receive calls.

PoE(Power over Ethernet) - this will allow voice over IP phones to be powered by using the network instead of a power cable that plugs in the wall. This is advantageous that all of the phones can be powered right through the computer from a single source, which is more efficient when creating the battery backup plan.

UPS (Uninterruptible Power Supply)- This device keeps power to the equipment even in the event of a power outage. The system has a battery that is built in which keeps the devices in full operation mode when the power is out.

The best way to protect the phone system from an outage is to use an Ethernet switch that will be where the router is located. This is advantageous when all of the phones are powering up from a single point in which then can be backed up by having a UPS. Make sure all of your equipment; the router, modem, Ethernet switch is backed up into a UPS device so the phones will stay running even when the power goes out.