A1 VoIP RequirementsGetting Started 47Via WAN (PPP: Point-to-Point Protocol)ExampleConsider the following case as an example:• Communication: via LAN• No. of Fax Machines: 2• G.711 Packet Sending Interval: 20 ms (requiring 87.2 kbps per channel)• G.729A Packet Sending Interval for Voice Communication: 20 ms (requiring 31.2 kbps perchannel)In this case, the required bandwidth will be as follows:Therefore, inform your network administrator and make sure that the network can support abandwidth of 611.2 kbps even when the network is under conditions of maximum traffic.NoteIt is recommended that all cards in a VoIP network have the same packet sending interval.Additional InformationAs described above, it is possible to control the required bandwidth by selecting a certain combinationof CODEC and packet sending interval. However, it is also possible to control required bandwidth bylimiting the number of available VoIP channels.The card supports a total of 8 ports, each having 2 separate channels. By disabling some of the ports,you can reduce the bandwidth required for VoIP communications.CODEC Packet Sending Interval20 ms 30 ms 40 ms 60 ms 90 msG.711 84 kbps 77.3 kbps 74 kbps 70.7 kbps —G.729A 28 kbps 21 kbps 18 kbps 14.7 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 kbpsRequired Bandwidth= (2 × 87.2) + [(16 - 2) × 31.2]= 611.2 (kbps)
