When learning how to calculate bandwidth for VoIP, it is important to know exactly what bandwidth is and how it is important to the running of your VoIP phone system. Basically bandwidth means the total packet size, or is classified as the width of the range – or band – of frequencies that an electronic signal is able to use based on the transmission medium. Basically bandwidth controls your Internet speeds, the uploads and downloads and overall Internet usage. Having a strong bandwidth is going to give you a more reliable Internet connection. Because your VoIP phone system runs entirely through your Internet Protocol, it is important to have a strong amount of bandwidth or you will end up with a weak phone connection. If you are using your VoIP system for business, you are going to need to have a reliable connection or you will risk losing business.
How to Calculate Bandwidth for VoIP:
Before you begin, it is important to note that for many of these questions, you might want to consider asking your Internet provider support team if you have any question about this information. Your Internet provider is also capable of letting you know what your bandwidth is as well. For another easy bandwidth solution, you can always use a free Internet speed/bandwidth test. This test will calculate your Internet speeds and bandwidth for you. However, if you want to know how to calculate bandwidth for VoIP by yourself, keep reading for a step-by-step tutorial.
First, it is important to find out the codec that is used by your VoIP software. This is the conversion standard from sound to digital signal. Out of the eight different codecs, some of them have more than one bit rate, which is derived from the sample size or sample interval. The codec sample size is basically the number of bytes that are captured by the Digital Signal Processor (DSP) at each interval. Next, you will need to find out what Layer 2 system you are operating. Typically this will be Ethernet, Multi-link Point-to-Point Protocol (MP) or Frame Relay Forum (FRF.12). Because each of these creates a different sized overhead in the packet header. This is how you will know how many bytes to use based on this Layer 2 system.
Next, find out the transport and session layers that your program uses. This is used to calculate overhead. Typically this might be around 40 bytes depending on your Layer 2 system. Using this information combined with the Compressed Real-time Transport Protocol (CRTP). Now you can calculate the total packet size in bytes. Use this formulate to get the total bandwidth:
Total packet size = Layer 2 header + IP/UDP/RTP header + Voice Payload Size. This will give you the total packet size.
Alternatively, you can use a second formula:
PPS = codec bit rate/ voice payload size. For VoIP purposes, the available bandwidth capacity would need to be strong enough to enable the transfer of at least 50 packets per second. From here, you can calculate the bandwidth requirement using this formula:
Bandwidth = total packet size * PPS
If you need help with getting any of these numbers, it is important that you ask your Internet provider. Otherwise you risk doing your calculations incorrectly and coming up with the wrong amount. Having the wrong amount for your actual bandwidth can affect what kind of service you can get from your VoIP provider. When you first get set up with your VoIP programs, software and communication devices, make sure and talk to the VoIP provider about the requirements necessary from your bandwidth performance to be able to operate your VoIP phones successfully.