Voip stands for voice over internet protocol. Basically it means talk through internet.
Many different voip calling services are available using different protocols. With the traditional IM softwares like msn, yahoo, qq etc, people have been able to do voice and even video chat for a while. Now all different IMs tend to converge as one universal. Jabber is one way that is trying to make it. Skpe is another unique one which is one the most popular voip services over the world. And there are a lot of other sip voip services which each provides a sip proxy for configuration. All sip services are pretty universal. They can communicate with each other pretty easily provided people are allowed to by the company meaning they each have a open server.
1. PC to PC
I believe all softphones with different services and many IM softwares can do pc to pc talk, even with video. People have been using msn, yahoo messengers etc to talk for a while.
Companies tried to make people feel like using traditional phones, and thus made some USB phones. The phones are connected to computers through USB cable. To make a call, we have to have computers on(Of course with internet access). Different USB phones support one or multiple different services. And it can be used for skyple, and/or msn/yahoo, and/or sip services. Basically, the phone just act as a dialpad.
2. PC to Phone
Some IMs were trying to make calls to regular phones. With AIM, people can make calls to phones with various calling plans. And we have seen dialpads with windows live messenger, google talk. Using skype, of course we can call phones with calling credits. For sip services, there are some universal softphones, such as popular ones like x-lite/eyebeam (www.counterpath.com), sjlabs(www.sjlabs.com) etc. Some companies only allow people to use their own specific softphones. A lot of companies allow people to set up the service on universal voip softphones. Some IM/Jabber services provide bridging services through their gateway so people can use sip accounts to make calls through their IM/Jabber accounts, such as Talkonaut, Gtalk2Voip etc.
You may think why phone-to-pc. What’s the value of it? If we can call from phone to phone, why calling pc? Doesn’t it make any sense?
Now, here are two scenarios.
You are in US and your friend is in Paris. You can’t find a cheap voip to make calls. And you can’t stay in front a computer to chat/talk with your friend. You want to use phone. What do you do? Buy the expensive voip service or calling card? Sure if you don’t care spending money. Here we are talking about saving money. Sometimes, your phone is the only thing you can use, then how?
You are somewhere and want to make international calls. But you have no internet. You can’t find a call back service either. Now what can you do?
Phone-to-PC may be your solution. It’s not available everywhere. You need check. Sipbroker(sipbroker.com) can help us to make free phone-to-pc calls. So just check if there’s local access number in your area.
(Check access numbers here: http://www.sipbroker.com/sipbroker/action/pstnNumbers and provider codes here: http://www.sipbroker.com/sipbroker/action/providerWhitePages)
Basically, you call your local access number and transfer to your friend’s voip account. If your friend set the account on a voip device, it becomes kind of phone-to-phone calling.
Get a local DID of your area for your friend who’s in another country and you call the DID is another way. People can get free DID in the US. But usually, people need buy.
4. Phone to Phone
I believe this is the solution that people like the most. Like using softphone, for some companies people have to use the voip devices they specify. And some allow people use to their own ones which is called BYOD(Bring Your Own Device). Almost all big companies specify devices by doing which they have more control of their customers. A lot of other companies provide pretty decent pricing and people can can do BYOD. But if the company is very small, they may not spend much effort on their services. Voice quality may not be very good. And customer care could be poor.
5. Calling Card
This can be regarded as another phone to phone solution. The difference from phone to phone solution above is that you don’t personally need a computer or internet to use it. The company has access numbers for customers to call through. It’s called calling card method. It differs from traditional calling card by it’s technology. To customers, it works just like traditional calling card. But it can make calling easier than traditional one. Basically, customers can register their phone numbers in the company’s system. When they call the access number, they don’t need put in a very long ID+password. They may or may not need type in a short PIN number. FreeCallPlanet.com(was CallChinaForFree.com) is one of this kind.
6. Call Back
This is another way for phone to phone talk.
It has various connecting methods.
- One is web callback. Jajah is one the most popular ones of this kind. People need a computer and internet to make the connection. Basically, they put in their own number and the destination number and make the connection. Both sides will receive calls with calling side first usually.
- Another way is SMS Callback. People send a message to the access number. Then they will receive a call from the gateway. Then they are prompted to type in the destination number to make the connection.
- Another one is direct callback. This is the way to avoid any charge by the phone comany for dialing. People dial the access number. The call will be disconnected before it’s through. Customers are not charged. But the gateway has already received the signal. So then the customer will receive a call from the gateway to make the connection.
Call back is comparatively more expensive because customers need pay for two connection legs. Rebtel(www.rebtel.com) is one of this kind.
7. Mobile Voip
Actually this not another technique out of above. But it’s a calling style which becomes or will become more and more popular. More and more companies provides specific voip softphones for mobile(Pocket PC or Smartphone), like skype. Most of sip services can already be configured on universal softphones(for mobile). Please see more in Smartphone/PDA category for such services and softphones. Some companies provide mobile access site to make web callback. Of course people can always do direct callback with mobile if available. But sometimes, the access number is from another country, I guess people will not usually call an access number directly from mobile?
Actually, some comanies provides multiple ways of above. Who allow people configure the service on voip softphones/devices may also provide calling card and/or callback services.
It’s worth pointing out that Asterisk/Tribox is a pretty powerful solution which could be for personal or companies. With asterisk, basically, we can have our own phone system. All features can be achieved by right settings/installations.
The last but not least, DID number is another powerful tool. Some companies like freedigits provide free DID numbers. Please see more about DID numbers in DID category. If both sides are using their services, they can make voip phone to phone calls by dialing real phone numbers. And they can receive incoming calls. DID numbers can also do call forwarding to sip URI or phone numbers. People can get a DID number of another country and forward calls from that country to their phones using VOIP. With grandcentral(www.grandcentral.com now with google), people can get a free local number with a lot of features. And they can make free web callback within US and Canada.
With DID, people can even make calls between regulars phones using voip without own internet connection. Some people may like it because they dont’ have or don’t want to use computers or internet devices. Here’s one example to make it. You are in US. You get a free DID from freedigits. Then you buy voipbuster. You could forward your calls received on freedigits to sip:firstname.lastname@example.org which can be done in your freedigits account. Then you could forward your voipbuster calls to an international number. Now if you call the US DID number, you’ll reach an international number. The thing is you need specify the forwarding number in the account. If you usually only call one family number, it is good for you. You just need set the forwarding number one time. To call any numbers, asterisk can make it. But that’s more complicated.
In a word, there can be many different ways to use voip. You could design your own way for your convenience. It’s all up to your imagination.