As VoIP is run over a broadband connection, before you consider integrating VoIP with your CRM account we

recommend that you read the following document so that you understand the requirements in terms of broadband speed, suitable routers and interpreting the results of a speed test.  


VoIP - System Requirements, Routers and Speed Tests


Switching from a traditional telephone service to voice-over-IP (VoIP) requires sufficient bandwidth (speed), a proper switch and router, and a good battery backup solution to protect you from power failures. 


A number of factors must be considered when setting up VoIP including how many users you will have on a single internet connection and how many of those users will be on the phone at once. 


The key voice-over-IP requirements discussed here before you do your VoIP speed test are:


Bandwidth - Determining how much bandwidth you will need for voice-over-IP in your office is your first step.


The Router - Choosing a low quality or under-performing router is a costly mistake which will degrade your call quality - please click here to view some information on compatible and incompatible routers for VoIP. 


Quality of Service - QoS - You must decide whether voice traffic will be separated from regular internet users or if it will share the same network.


VoIP Equipment – We have a range of Desk or Dect portable phones and headsets we recommend to ensure high quality calls please click here to see further information. 


Power Failures - Voice over IP does not work when the power goes out so you should install a battery backup system and possibly a Power-over-Ethernet switch if your budget permits it.


Available Bandwidth 


The first item examined during the VoIP speed test is bandwidth. Bandwidth measures how much data your internet connection can send (upload) and receive (download) over a time period of one second. 


In most cases your upload bandwidth and download bandwidth will differ considerably. 


Upload bandwidth is the limiting factor when determining whether you have enough bandwidth to sustain a certain number of concurrent telephone calls using VoIP.

As an example, a typical voice call requires 87 Kbps of upload and download bandwidth. Did your VoIP speed test indicate that you might not have enough bandwidth for your desired number of users?


How much bandwidth do I need? 


Voice over IP needs a certain amount of bandwidth in order to keep your conversations clear and free of disruptions. Bandwidth is the amount of information which your internet connection can send and receive in a certain period of time. 


Your first step should be to use an online speed test to find out what your maximum upload stream and download stream is. We suggest you do this test using a fixed connection to the internet rather than using your wifi (wireless) connection to get accurate results.


Try to use numerous tests during different times of the day to get a good average of what you can expect from your internet connection. Bandwidth is normally measured in kbps or kilobits per second. 


You will need to have a high speed (broadband) connection to use voice-over-IP.  

A typical DSL connection will be rated at 600 kbps for the upload stream and 5000 kbps on the download stream. You will notice that your upload stream is almost always smaller than your download stream which becomes your limiting factor for using a VoIP service. 


Your next step is to determine how many people in your office are likely going to be using the phone at the same time. For instance, having ten people on the phone will require ten times as much bandwidth as having one person on the phone. 


Below is a chart which will help you calculate how many people can be on the phone at one time: 


Ask your voice-over-IP service provider what audio codecs they offer as there is a trade-off between audio quality and bandwidth usage:


  • Full Quality Audio (G711 Codec) - Uses 87 kbps for each concurrent phone call (NEB)
  • Compressed Audio (G729 Codec) - Uses 33 kbps for each concurrent phone call (NEB)


So the calculation for a typical DSL connection would be: 


DSL connection: 600 kbps upload / 5000 kbps download 


Gives us (Full Quality): 600 kbps / 87 kbps = 6 concurrent calls 


Gives us (Compressed Quality): 600 kbps / 33 kbps = 18 concurrent calls 


Notice we used the upload bandwidth in our calculation as this is the limiting factor for voice-over-IP. 


You also do not want to push your connection to the limit as most cable and DSL connections do not have guarantees in terms of how much bandwidth they will deliver. 


If your Internet connection drops in bandwidth at some point during the day you do not want your call quality to be affected. 


Other factors affecting voice-over-IP are the latency (ping) of your connection and how much packet loss there is on it.


The VoIP speed test considers a wide range of factors that determine your connections suitability to VoIP; please read the results carefully.


What can I do to get even faster upload speeds and bandwidth with my current broadband ADSL package?


If you are unable to access Fibre Optic Broadband i.e. BT infinity in your area and can only get ADSL broadband then speak to your current or new Internet provider to see if they can provide your business with Annex M bolt-on.


What is Annex M?


Annex M is the latest generation of broadband technology that allows for greater upload speeds as a bolt-on to ADSL broadband. 

Annex M can potentially increase upload speed to 2.5 Mb, and is available as an enhancement for those customers who could benefit from faster uploading, including remote workers, heavy email users and those who need to regularly upload large files.


Can it improve VoIP bandwidth and speed?


Other reasons that businesses choose to upgrade to an Annex M connection include more effective video conferencing, more bandwidth for voice over internet protocol (VoIP) calls, and sending offsite backup information faster.


When using VoIP as well as running your CRM your business would benefit from an upgraded ADSL package that includes Annex M.


Choosing a router:


A router is the device that connects all your computers and network equipment to your Internet connection. It is an often overlooked piece of the puzzle that can have a major impact on the success or failure of your voice-over-IP implementation. 


There are many routers on the market, some are very cheap and others can cost you thousands of pounds. 

There is nothing worse than putting a poor quality or under-powered router in your office which could cause an otherwise good VoIP installation to go bad.  


Your router needs to be powerful enough to handle the number of phones you will have in your office and should also work flawlessly with voice-over-IP equipment.   Please click here to view some information on compatible and incompatible routers for VoIP. 


We also recommend checking to make sure that your router is compatible with voice-over-IP services, such as being able to disable the SIP ALG setting and enable DHCP on your router is essential for good quality VoIP. 


The following is a list items which will help you to determine whether your router is right for voice-over-IP: 

1. How many voice-over-IP phones will you be connecting to the router? The more phones you will be connecting, the more powerful the router needs to be.  Do not use a cheap router to run an office with 10 IP Telephones.


2. Will your voice-over-IP phones have their own dedicated Internet connection?  If not, a router with a quality of service (QoS) setting to prioritise voice traffic over regular traffic is an absolute must.  Without QoS you will encounter poor quality telephone calls regularly.


3. What other functions will the router need to perform? You might need your router to handle VPN connections, allow wifi (wireless) connections or perform other tasks.


4. Make sure you can bridge your router to your modem. Routers that are not bridged can cause problems with voice-over-IP installations.


5. Never use more than one router or NAT gateway on the network at a time as this will cause problems for IP telephones when they attempt to do NAT.


6. Is your router on a fixed or dynamic IP address?  If using a fixed IP address we will need to configure your VoIP phone equipment specifically for this so it is important you let us know this by contacting our Support Helpdesk. 

We recommend the following routers for compatibility with VoIP:

  • Technicolor TG582n PRO or the TG589n
  • Cisco RV042(G) / RV082 / RV016 / RV110W / RV180W / RV320
  • Cisco Integrated Services Routers (1900/2900/3900 series)
  • Draytek 2830 / 2820 series
  • ZyXEL range
  • Netgear DG834(g)/ DGN2000 / DGN3500  /WNR2000
  • Linksys by Cisco ADSL and cable routers


Please note there are some known issues with using a Virgin Hub for VoIP as many have found they are unable to make outgoing calls with a Virgin Hub.  If this happens you can purchase a new router and put the Virgin router into ‘bridge’ mode.

Battery backup and Power-over-Ethernet


With voice-over-IP and most office telephone systems you must consider what happens when the power goes out. For some offices this can be a regular occurrence and for others it might happen with a very low frequency. Once of the things you will need to decide is whether or not you will install a battery backup system.


Here are a few important terms you should know: 


  • Power over Ethernet (PoE) - is a technology that allows VoIP over IP telephones to be powered using regular network cables rather than power adapters which plug into the wall. This has the advantage that you can power all the phones in your office from a single source and makes installing a battery backup unit much easier.  You can purchase a PoE kit at:


The easiest way to protect your phone system from a power outage is to power all the phones using a Power-over-Ethernet (PoE) switch that would normally be connected in the back room where your router and cable/DSL modem is located. This has the advantage that all your phones are drawing power from a single source which you can backup using an uninterruptible power supply (UPS). 


All you need to do is plug in your PoE switch, router, and DSL/cable modem into a sufficiently powerful UPS device so that when the power goes out all your phones remain up and running. 


Speed Tests 


For VoIP, enough bandwidth must be supplied to allow for the transmission of voice data in real time.  

In order to establish the quality of your broadband to support a VoIP line we ask that a speed test is carried out. These tests are done online via  


The VoIP speed test below will test ping (latency), download speed and upload speed results that you can use to evaluate your broadband connection.  


Download speed: When you connect to the internet, the download speed is the pace at which data (websites, programmes, music etc) is transferred from another source to your device. 

For VoIP the higher the download speed the better for call quality. 


A slow internet download speed can become very annoying if your downloads take forever and the video clip you are trying to watch keeps stalling.  As a general rule, if you are going to rely on downloading a lot of content, or play a lot of online games, it is definitely worth looking at getting the fastest connection you can comfortably budget for.


Upload Speed: this is the speed at which data is uploaded to the internet – such as posting on social networking site such as Facebook, or to upload images to a company website.  


 The higher the upload speed the better – for instance 10mbps (megabytes per second) is a very good score.  Essentially, the upload is going in the opposite direction to the download - from your computer to someone else.


Broadband upload speeds are generally much slower than download speeds. The reason for this is that people generally do far more downloading than uploading, so downloading is given priority by the ISPs.


Upload speeds are more important to people who are going to be doing large amounts of uploading, such as someone who works from home and wants to exchange files with a remote network, or people who play a lot of online games - especially if they are hosting them themselves.


Again, distance from your telephone exchange, as well as other considerations such as old household wiring, can also be factors in slowing down your upload speed.   As a minimum we can accept 1 or 2 Mbps for upload speed.


Ping (latency): This measurement tells how long it takes a "packet" of data to travel from your computer to a server on the Internet and back.  Whenever you experience delayed responses in Internet applications - this would be due to a higher than desired ping.  Similar to packet loss, lower is better when it comes to ping which is measured in milliseconds.

A result below 100 ms should be expected from any decent broadband connection.


Different Results at Different Times 


Why might you get different results from a VoIP speed test at different times? Networks are dynamic environments and conditions can change depending on network usage, time of day, and other factors. 


It is best to run the VoIP speed test a few times at different times of the day, or after you experience a network related problem, to try to determine the source of the issue. For instance, you might experience a voice drop-out when an employee is uploading a large file but not at other times. 


If you did not have Quality of Service (QoS) set up properly this would affect your voice conversation and thus it would only appear on a VoIP speed test if the employee was still uploading the file - once they had finished the upload, the test might indicate perfectly good results.