Lines and VoIP Bandwidth Calculator
This calculator can be used to estimate the bandwidth required to transport a given number of voice paths through an IP based network. Reverse calculations are also possible. These estimate the number of voice paths that can be transmitted though an IP network if the available bandwidth is known. Before a calculation can be performed, details of the voice compression scheme must be entered into the first two areas of the calculator. * Use the first drop down box to select the CODEC being used. CODECs convert analogue voice signals into data streams through sampling and quantisation. CODECs vary in their quality and delay characteristics and, although there is not yet an agreed standard, G.723.1 and G729A are the most common CODECs used for Internet voice transmission. * The frequency at which the voice packets are transmitted have a significant bearing on the bandwidth required. The selection of the packet duration (and therefore the packet frequency) is a compromise between bandwidth and quality.
VoIP Bandwidth Calculation
The amount of bandwidth required to carry voice over an IP network is dependent upon a number of factors. Among the most important are: * Codec and sample period * IP header * Transmission medium * Silence suppression The codec determines the actual amount of bandwidth that the voice data will occupy. It also determines the rate at which the voice is sampled. The IP/UDP/RTP header can generally be thought of as a fixed overhead of 40 octets per packet, though on point-to-point links RTP header compression can reduce this to 2 to 4 octets (RFC 2508). The transmission medium, such as Ethernet, will add its own headers, checksums and spacers to the packet. Finally, some codecs employ silence suppression, which can reduce the required bandwidth by as much as 50 percent.
Bandwidth is Required for VoIP Phones?
A long-standing question for potential VoIP (Voice over Internet Protocol) consumers is first of all, Bandwidth is defined as the ability to transfer data (such as a VoIP telephone call) from one point to another in a fixed amount of time. The higher the bandwidth speed you have, the more data you can send over your Broadband Internet connection. There are two types of bandwidth at your location: upload bandwidth and download bandwidth. The Upload Bandwidth is the amount of data you can send to the Internet and download bandwidth is the amount of data you can receive from the Internet. The more Internet bandwidth you have from your ISP (Internet Service Provider) the better.
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