Getting the best from your service.


What type of broadband connection do I need for the phone system?

We recommend a dedicated FTTC (Fibre to the Cabinet, or superfast broadband connection). This is more to do with the stability of the connection rather than the amount of data bandwidth that is required.

However we offer a free software trial so that you can try it yourself and see what you think? On the front page of the site there is a timer that measures the round trip time to our servers showing you whether the speed of you connection will manage the demands of voice at all.


Our customers have found that running a system on an ADSL 2+ connection is fine most of the time. But the electrical signal over the length of the signal sometimes leads to occasional dropped packets. With Fibre to the Cabinet the electrical signal has a very short run and is therefore much more stable.

Shared Circuit

Voice uses very little space on a broadband circuit. So why not share? The reason why we recommend dedicated broadband circuits is that occasionally with shared broadband circuits during a large data download the data can bleed into the voice and interrupt call quality. There is nothing you can do about this. Programmes are designed to use all available connectivity, so youtube, Microsoft 365, Dropbox, Google drive will use all the connection they can get. With voice data getting swamped. So most of the time your voice calls will be fine, and occasionally there will be a call quality issue.

This is the same with all providers because the data download swamps the router before any management prococols can priortise the traffic.. The only way around this is a managed shared circuit which is more expensive than a dedicated voice circuit.

You could try and get away with it on small sites by allowing calls divert to voice mail or mobile where they are avoiding the swamped circuit allowing you maintain good call quality.

Dedicated Circuit

The fibre is more stable and there is no interference from other programmes giving you stable voice all of the time.

Interpreting the results

Normally the upload speed is slower, and therefore the limiting factor. The amount of data a voice uses makes depends on the codec. Typically, a mobile call will use 30kbps of data. Normally the system is set to provide for a higher quality of call by using a codec that uses 100kbps.

So if you achieve an upload speed of 434kbps then your circuit should be able to support upto 4 simultaneous calls. If you adjust your codec to G729 (or similar), it could support 13 / 14 calls.

A 2Mbps would support 20 calls using a 100kbps connection.

Poor broadband Connectivity

You can still use this system with poor or no broadband. You just use it to manage the inbound calls and then forward the calls onto other telephone numbers. Follow the link for the services that you can use.


This is a measure of the variability of the connection speed. If the Jitter score is above 10 then you should expect some call quality issues. If the score is above 20 then you should not use the circuit for voice calls.

Sometimes you might find that a wireless or mobile connection has reasonably fast speeds but the jitter means that the call quality can be unsatisfactory.

Ping test

This is the round time journey for a packet of data. A Ping score of under 100 should mean voice will work well. A score of over 150 will lead to call quality issues.
It is worth running the test several times during the day and collating the results to tell you how the circuit is working.
Try our own tests on your connection. The guide will tell you whether the connection will support VoIP cleanly or not. The time sequence tests should give you a read over a whole day.