This process includes some steps that we dont know about and how mere a telephone could be connected with the ethernet or internet and communication process goes on. Better to say that VoIP uses PSTN as its path and moves on. In a regular telephone when we speak that speeches are carried out by dedicated telephone lines and those signals are analog signals and reaches to recieving end as an analog signal. No conversion happens at the time transmission. But in this telephony conversion happens when the ssignal is transmitting. When speaker speaks at that time the “SPEAK” (Signal) converted to digital signal and those signals forms a packet which is divided in several packets and then transmitted through the PSTN to the reciever. The signal got also compressed and sent it over the IP protocol and the whole process gets reversed at the recieving end.
Now people must think that as it is a VoIP so does it own a IP address dedicated for this VoIP?
Or how the process goes on as it is said PSTN (Public Switched Telephone Network) as its path?
Well, for those answers I must give some information about Switching. That is in a plain networking switching refers to a communication between two or more computers but dedicated path.Here's also the same route is adopted i.e. Dedicated lines between talkers and there are 2 satges with which they can setup (Set-Up Phase) their lines and talk over it and at the end it will execute the Tear Down phase. And as well as when the signal got transformed to digital signal, it must have to use some audio codec to transform, it has a variety of codecs in audio signals and that varies between the several implementations of VoIP. And for the first question that does it need any IP Address? Well, no we dont need that beacause, it should be connected to the computer and specially it is not supporting mobility.
Another point I must include that VoIP supports session protocol which means it does senses the line continuously for its activieness but when it sense that the line is idle for some long time it will automatically cut the line off. We need to reconnect the line to move on. For the connection you need to have three mandatory thing:
1. ATA (Analog Telephone Adapter): The work of that adapter is to connect two lines one is analog phone line and another is for the computer or DSL Broadband line and the adopter must be at a static location. Both lines performs when we talk. eg. Vonage, AT & T CallVantage are the phones which comes free with the service. Sometimes it has some softwares to setup the phone but anyhow those software setups are very easy and straight forward.
2. Dedicated VoIP Phones: The specialized look of the the phone is nothing but ut has a small screen at buttons that to cradle. But instead of RJ-11 connectors the phone has RJ-45 Connectors to connect with the broadband. Ip phones can be directly connected to the router and it has all ecessary softwares and hardwares in it onboard. It needs to be paid to get the service from VoIP providers.
VoIP PHONES
3. Computer to Computer: The certainly most easiest way to make a call for a long distance you need to have computer, a software, Internet Connection, Sound Card that's it. Companys even dont charge of any kind for a the call except the monthly fee.
VoIP DIAGRAM
Using these stuffs you can do VoIP calls but at a lower cost (if needed). There is a lot of difference between normal analog telephone and a VoIP telephone. We are talking a lot about this but we haven't mention yet that why should we use VoIP telepehones? We should use this service because, the cost of time depends a lot. Now-a-days human being gives more cost for time than any item. This leads us to a new technology VoIP. In a normal telephone it requires almost a lot of time whereas in VoIP the time becomes less to talk.
Lets give an example, suppose a man talks to a man for 10 minutes. But think the call makes a route from New York to Los Angeles means a 3000 Mile. So in a normal telephone what happens when some body makes a call that call goes through a set of switches which is scattered throughout the city. In this case it happens so and it travels a 3000 mile copper wire and holds the line for 10 minutes. Think how much cost we are paying for a mere 10 min call. Why does it take 10mins? Bacause the line is made of copper and less efficient to carry out the signals and data compression not supported by this regular telephone system. But if the conversation needs 10mins in a regular line it will take only 3.5 mins in a VoIP line means, in internet telephony.
Save time to Save Money.
On the other hand as VoIP uses packet switching which gives us the provision of sending signals or for communication a little cost for a little time. For a 10mins phone call we consumed 10 full minutes for transmission timeat a cost of 128Kbps. But with VoIP that same call takes only 3.5 minutes of transmission time at a cost of 64Kbps, leaving another 64Kbps free for that 3.5 minutes plus another 128 Kbps for the remaining 6.5 minutes. That means easily another 3 or 4 phone calls can be placed using the same conventional line.
Some steps of this VoIP communication is:
1. reciever is picked up and which sends a signal to ATA (Analog Telephone Adapter)
2. the adapter recieves a signal and sends a dial tone to sender. In this case it simultaneously makes you know that you are connected to the internet.
3. Phone number is dialled and that number goes to the VoIP company's call processor and before that it is being digitized by ATA adapter.
4. The processor checks its validity and makes the call after mapping it and translated it into a IP address.
5. The soft switch (the software that comes with the adapter and handset) connects two devices on either end of the call. On the other end the signal goes to receiver's ATA telling it to ask the connected phone to ring.
6. Once riciever picks up the phone a session is established between them and packets are sent via the path. In the middle of that call the call is handelled by the internet infrastructure just as a email or a webpage. Both the sender and reciever should use the same protocolto communicate.
7. When the call is on the go the packets are being transmitted by the ATA to analog audio signal at each end at each transmission.
8. At the end of the call the session has ended the switch is closed.
This technology is such a boost to the huge communication system still it is not available for some possible reasons like: viruses, hacking, NANP calls, and most significant drawback is power means, if power goes out the phone dies immediately.
We hope that these drawbacks will be filled soon with the solutions and will enter our life and will save our money that is “TIME”................. :) :) :)
