How much Bandwidth do VoIP calls use?
Bandwidth for VoIP
Now that we've spent quite a while discussing bandwidth management for VoIP, it's time to buckle down and get into the details. How much bandwidth does VoIP really use anyway?
Unlike PSTN systems where everything is standardized, there are no constants in the infrastructure that VoIP calls use. Therefore there are many different setups and each has its own peculiarities. Let's start off by determining the factors that have an effect on the bandwidth your VoIP calls are using.
One of the most important factors determining bandwidth usage is the type of codec that's being used to encode your voice. We've seen before that better codecs enable the transmission of voice in many more frequencies than regular PSTN allows. This comes at a cost though and when your voice is travelling along at 64 kbps compared to just 8 kbps on an analog line it uses up a lot more space.
Of course, there are many codecs in between. The G.711 for example is at the high end - encoding your voice at 64 kbps. You can choose to use the G.728 or even the G.726 codec for voice that is much clearer than a PSTN phone's but doesn't use up too much bandwidth.
The limiting factor here is your VoIP provider. Make sure that they support the type of codec you want, otherwise you'll be stuck without one of the biggest advantages of VoIP - namely HD voice.
Number of VoIP users
This is clearly the single most important factor affecting your bandwidth requirements. More people mean that more space is needed. However, to determine how much bandwidth to allot for your VoIP needs you need to figure out how many people are going to be using the system simultaneously at any given time. Then we also need to make allowances for peak situations, though they may be rare.
Keep in mind that something like a very large conference using VoIP can hog space because every user is making use of bandwidth at the same time. To accurately determine your needs, it's best to consult your VoIP provider. A good VoIP phone system for businesses will ensure that you're covered when you need it most.
The combination of these two factors will determine the totality of your VoIP needs. Don't forget to include the bandwidth on mobile VoIP phones as well. If lots of users are talking on a cell phone, that reduces the burden on your office infrastructure.