VoIPMaster 260W
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What is How does it | Many years ago we discovered that sending a signal to |
work? | a remote destination could have be done also in a digital |
| fashion: before sending it we have to digitalize it with an |
| ADC (analog to digital converter), transmit it, and at the |
| end transform it again in analog format with DAC (digital |
| to analog converter) to use it. |
| VoIP works like that, digitalizing voice in data packets, |
| sending them and reconverting them in voice at |
| destination. |
| Digital format can be better controlled: we can compress |
| it, route it, convert it to a new better format, and so on; |
| also we saw that digital signal is more noise tolerant |
| than the analog one (see GSM vs TACS). |
| TCP/IP networks are made of IP packets containing a |
| header (to control communication) and a payload to |
| transport data: VoIP use it to go across the network and |
| come to destination. |
| Voice (source) |
| (dest) |
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What | is | the | When you are using PSTN line, you typically pay for |
advantages | using | time used to a PSTN line manager company: more time | |
VoIP rather PSTN? | you stay at phone and more you'll pay. In addition you | ||
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| couldn't talk with other that one person at a time. |
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| In opposite with VoIP mechanism you can talk all the |
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| time with every person you want (the needed is that |
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| other person is also connected to Internet at the same |
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| time), as far as you want (money independent) and, in |
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| addition, you can talk with many people at the same |
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| time. |
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| If you're still not persuaded you can consider that, at the |
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| same time, you can exchange data with people are you |
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| talking with, sending images, graphs and videos. |
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