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Example calculation |
  
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Example calculation |
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How many lines can I derive from an IP based network path whose bandwidth is 1.544 Mbps? I am using the G.728 codec. I am not using any header compression and one IP datagram is being transmitted in each direction every 20ms.
To find out the answer to this question, follow these steps:
| • | Select the Lines to IP Bandwidth Calculator using the relevant tab at the top of the window. |
| • | Select G.728 using the Coding algorithm drop down box. |
| • | Select 20ms using the Packet duration drop down box. |
| • | Select No RTP header compression using the RTP header compression drop down box. |
| • | Choose Mbps as the bandwidth unit by clicking on the Mbps radio button on the right side of the window. |
| • | Click the Unknown radio button in the Voice Paths (lines) area to indicate that you wish to calculate the number of lines. |
| • | Enter 1.544 in the edit box in the Bandwidth (Mbps) area. |
| • | Press the Calculate button. |
After a short time, 48 will be displayed in the grey edit box. This is the result of the calculation, and shows that 48 voice channels can be transmitted through a 1.544 Mbps IP link using the selected VoIP characteristics. This result does not take any layer two overhead into account.