A1 VoIP Requirements52 Getting StartedA1 VoIP RequirementsA1.1 Bandwidth AssessmentTo establish a VoIP network, you must ensure that the network has enough bandwidth tosupport VoIP communications. Inform your network administrator of the required bandwidth,and make sure that the network can support VoIP communications even under conditions ofmaximum network traffic.Bandwidth CalculationProvided below is the formula to find out the amount of bandwidth required for VoIPcommunications:Required bandwidth for fax and voice communications for one VoIP channel is shown in thetables below (for more details, refer to "2.2.3 Voice Communication Parameters" in the VoIPGateway Card Programming Guide).Required Bandwidth for Voice CommunicationVia LANVia WAN (PPP: Point-to-Point Protocol)Required Bandwidth= (No. of Fax Machines × Required Bandwidth for Fax Communication) +[(4 - No. of Fax Machines) × Required Bandwidth for Voice Communication]CODEC Packet Sending Interval20 ms 30 ms 40 ms 60 ms 90 msG.711 87.2 kbps 79.5 kbps 75.6 kbps — —G.729A 31.2 kbps 23.5 kbps 19.6 kbps — —G.723.1 5.3 kbps — 20.8 kbps — 13.1 kbps 10.5 kbpsG.723.1 6.3 kbps — 21.9 kbps — 14.1 kbps 11.6 kbpsCODEC Packet Sending Interval20 ms 30 ms 40 ms 60 ms 90 msG.711 84 kbps 77.3 kbps 74 kbps — —G.729A 28 kbps 21 kbps 18 kbps — —G.723.1 5.3 kbps — 18.7 kbps — 12 kbps 9.8 kbpsG.723.1 6.3 kbps — 19.7 kbps — 13.1 kbps 10.8 kbps