You need to be aware that with VoIP, your organisation will potentially be using the same network for transfer of all files, emails and voice communications.
It is sometimes the case that because of the above, the quality of calls may not be as clear as traditional voice systems. However, recent technological advances make this less likely to happen.
As a result, you need to ensure that the infrastructure, such as cabling, your server and internet access, is able to handle voice as well as a high volume of data. VoIP doesn’t require much bandwidth, but it is advisable to check that your system can cope. These days, getting more bandwidth is simple (and inexpensive). Just speak to your current supplier who can easily increase the capacity.
Your voice and data are tied into one network and you’ll require access to the internet, so if there is an issue with either one of these, then you will lose voice communications too. So, if you lose internet access then you will lose the ability to communicate using VoIP.
Another point worth bearing in mind is that because VoIP utilises the internet, the system is susceptible to the same potential security threats as any other internet service.