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VoIP Bandwidth Calculation |
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.
Newport Networks provides a tool to calculate the bandwidth your VoIP system .
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Codec
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Bandwidth
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Codec & Bit Rate
(Kbps)
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Codec Sample Size (Bytes)
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Codec Sample Interval (ms)
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Mean Opinion Score (MOS)
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Voice Payload Size (Bytes)
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Voice Payload Size (ms)
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Packets Per Second (PPS)
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Bandwidth MP or FRF.12 (Kbps)
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Bandwidth w/cRTP MP or FRF.12 (Kbps)
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Bandwidth Ethernet (Kbps)
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G.711 (64 Kbps)
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80 Bytes
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10 ms
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4.1
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160 Bytes
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20 ms
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50
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82.8 Kbps
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67.6 Kbps
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87.2 Kbps
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G.729 (8 Kbps)
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10 Bytes
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10 ms
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3.92
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20 Bytes
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20 ms
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50
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26.8 Kbps
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11.6 Kbps
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31.2 Kbps
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G.723.1 (6.3 Kbps)
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24 Bytes
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30 ms
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3.9
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24 Bytes
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30 ms
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34
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18.9 Kbps
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8.8 Kbps
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21.9 Kbps
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G.723.1 (5.3 Kbps)
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20 Bytes
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30 ms
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3.8
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20 Bytes
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30 ms
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34
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17.9 Kbps
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7.7 Kbps
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20.8 Kbps
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G.726 (32 Kbps)
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20 Bytes
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5 ms
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3.85
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80 Bytes
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20 ms
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50
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50.8 Kbps
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35.6 Kbps
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55.2 Kbps
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G.726 (24 Kbps)
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15 Bytes
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5 ms
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60 Bytes
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20 ms
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50
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42.8 Kbps
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27.6 Kbps
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47.2 Kbps
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G.728 (16 Kbps)
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10 Bytes
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5 ms
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3.61
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60 Bytes
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30 ms
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34
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28.5 Kbps
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18.4 Kbps
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31.5 Kbps
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Voip Bandwidth Calculation 