# How to calculate the bandwidth occupied by various codes after VOS media forwarding is enabled

The VOIP calculation method is as follows:

Bandwidth = packet length × number of packets per second

= packet length × (1/packaging period)

= (Ethernet header + IP header + UDP header + RTP header + payload) × Packets per second

= (112bit + 160bit + 64bit + 96bit + payload) × number of packets per second

= (112bit + 320bit + payload) × number of packets per second

= (432bit + payload) × number of packets per second

= (432bit × number of packets per second) + (payload × number of packets per second)

= (432bit × 1000 / packing cycle) + encoding rate

= (432bit/packaging period) Kbps + encoding rate

According to the above formula:

G711: 20ms package, bandwidth is ( 432/20 ) Kbps + 64Kbps = 85.6Kbps

G729: 20ms package, bandwidth is ( 432/20 ) Kbps + 8Kbps = 29.6Kbps

G723: 5.3k, 30ms packed, bandwidth is ( 432/30 ) Kbps + 5.3Kbps = 19.7Kbps

G723: 6.4k, 30ms packed, bandwidth is ( 432/30 ) Kbps + 6.4Kbps = 20.8Kbps

According to the above formula, the Ethernet header is not included:

G711: 20ms package, bandwidth is (320/20 + 64) Kbps=80 Kbps

G729: 20ms package, bandwidth is (320/20 + 8) Kbps = 24 Kbps

G723: 5.3k, 30ms packed, bandwidth is (320/30 + 5.3) Kbps = 15.97Kbps

G723: 6.4k, 30ms packed, bandwidth is (320/30 + 6.4) Kbps=17.07Kbps

If the server forwards the media, both the voice of the calling party and the called party need to pass through the server, so the bandwidth usage needs to be multiplied by 2, refer to the following table.