PSTN number for VoIP phone

In order to enable people to call you from the PSTN, you must have a PSTN number. For VoIP calls, it is voice in between IP addresses connecting two accounts in a VoIP client. When both parties are online in front of the computer, it is easily conducted using some software clients. What we want to achieve is to not using software, which means, we don't need to be using the computer.

Therefore, your account needs to be online all the time using a hardware connection. In this case I am talking, it is the ATA we mentioned before. What your online client needs to do, is to forward all phone calls terminating at the certain PSTN number to your account within the client. For example, we are using the service from Voxalot, and the account number is 111222. We also got a free PSTN number that is 360.333-4444. Through the service of Voxalot, it will forward all calls to 360.333-4444 to the voxalot account 111222. The signal will be picked up by the ATA and my phone will ring. For outgoing calls, upon an rate agreed, i have put a certain amount of money in my Voxalot account. It will charge me for every minute I call out to a PSTN number. If I am calling within the Voxalot network, it is free.

To get a free PSTN number, there are a few possibilities. We got it through SIPphone.com. Recently Google bought the company Grand Central, in which you can also get free numbers (for only users in US). I have been wondering why would someone would like to give out numbers for free use if there is cost involved. It is originated from the loopholes in the phone subsidy policy in the US. The government pay subsidy to some remote area phone numbers according to the number of calls made. This gives the incentive of giving away these numbers for free for more frequent use by others because the local will get more subsidies for the use of these numbers. I am not sure whether this applies to all free phone numbers. The group of 360 number given by SIPphone was because of this.

Since the account number of your VoIP client is mobile, it is with you where ever you log in. As a result, the PSTN number also appears to be mobile. It is also possible to have multiple PSTN number connecting to one VoIP account, as long as you set up all of them forwarding to the same account. On the other hand, it is possible to direct your VoIP phone through different VoIP clients. You can easily manage voice service providers based on call quality and cost. This is what Voxalot wins in the VoIP calling market. It allows you to manually set up the outgoing calls' selecting carrier client. All these different VoIP clients have different rates for calling to different places. For example, calling to US from anywhere, Voipdiscount is free, and Gizmoproject charges one cent per minute. So you can set up in a way that calling a US certain number, the outgoing call will go though Voipdiscount, for free.

PSTN and SIP open standard

I have tried to convince Anirban to continue writing about this, he is too busy. I am not that busy, but I start to feel a little hard in explain all these. I will try my best. Before we describe the complicated system, we still have some basic ideas to clarify. This time, it is the difference between the PSTN and SIP phone.

PSTN (public switched telephone network) is the world's collection of interconnected voice-oriented public telephone networks, both commercial and government-owned. The feature of this phone comparing to VoIP phone is the inefficiency of the use of wires. When a phone call is connected, the wire transfer of the voice between two users at either ends will occupy the entire wire connecting them. On the contrary, VoIP involves sending voice information in digital form in discrete packets which allows lots of packets to share parts of their routes along the same wire.

SIP is an open standard for VoIP technology, which is like SMTP for email communication. We all know about SKYPE, but in fact SKYPE built their system on a proprietary protocol instead of SIP open standard. As a result, SKYPE can only work within its individual client. And SIP based network can be connected with users out of the box, since most of the hardware development are following the open standard, and they are able to exchange in the future. This is how the SIP based VoIP network can also be connected with the PSTN network. (Skype can also do this at the moment, but it involves a fee for the calls. For SIP based phones, you can easily find free services.)

So, what the VoIP technology does, is to let the internet carrying voice signals, and also possible to connect to the existing PSTN network. Every PSTN has a number, so VoIP also needs a number to communicate with it. If you want others to reach you, you should have a number that everyone can dial using their home regular PSTN phone. Where and why can you get a free PSTN number, let's keep it for the next time.

VOIP and VOIP ATA

VOIP (Voice Over Internet Protocol) is the service including any sound communication over the internet. What we have been mostly familiar with are SKYPE, MSN messenger, Yahoo messenger, Google talk. All these services have allowed us to talk over the internet, basically a communication from one computer to another computer. All of these are different software clients, which we might have to install a small program on our computer to be able to talk. What these softwares do, is basically converting your voice to digital signals and sending to the internet, at the same time, converting the received signals to voice in your speaker.

The VOIP ATA (analog telephone adapter) phone I am talking about, uses a hardware - the VOIP router. What the router does, is exactly the same as what the software chatting clients do: converting signals to support the internet talking. When using the software, we know we have to turn on the computer and lauch the program. However this hardware router, we can just keep it connected with the internet. If there is no power cut or network problems, the hardware will be all the time ready to send or receive signals to enable a phone call. Here is a picture of our router:
In US, i think most people have heard about Vonage, the internet phone. This company has spent a lot of money on advertisement. What it has done, is some more development based on this kind of hardware router. It also made the 911 calls possible, and providing you a local number. The final service is more than 20 dollars per months i believe. They lock the hardware in their own service. So when you look for a voip router, remember to buy one that is not locked to any internet phone services. You want to have an open router that you have the full freedom to configure.

With this critical hardware, the internet connection, and the regular telephones, till now we have collected all necessary hardwares to set up the VOIP ATA for phone calls. However, the critical part is still ahead, the configuration of the ATA is the key.

VOIP ATA phone - good and bad

It has been more than one year since we set up our home phone totally relying on the VOIP (Voice Over Internet Protocol) ATA phone. It has been working fine for us, and we have convinced my sistere to change their home phone also. Although we are not the only one who is using this, i still feel there are few people are aware of this option. I didn't do any research myself. Mr. Awaara should take all the credits for this work, and I just try to describe it here to the public.

Our phone is just like any ordinary home phone at home. The phone number is a little tricky. We were using a free PSTN number from the Washington state. The good part of this number is its ability to carry anywhere you go. Now we are in the Netherlands, friends in the US can still reach us by calling an US number. Doesn't this sound great? Meanwhile, we also have a UK number, a Netherlands number. Either of these number is called, our phone will ring. How is it?

The most important, it is almost free. The main investment was a VOIP router that we spent 90 dollars on it. Other than this, the past one year phone bill including all the international calls we made often, is less than 10 dollars. This is great, right? OK, let me summarize the plus and minus of this phone first:

PLUS:
1. Same number reached anywhere in the world as long as an internet connection is available;
2. Very low cost. For those who don't need an internet connection at home, this might involve a cost transfer from paying for a phone connection to an internet connection. I am sure you will get a lot more using the internet connection.
3. Flexible phone features: if it is a PSTN phone, you might have to pay for the extra service like caller ID, or call forwarding, all these are just an option you can select in VOIP ATA phone.

MINUS:
1. You might have to do quite a lot of research to understand the system and set it up and maitain it. But there is also lots of fun in this process.
2. There is no 911 service for this phone. Since 911 service need to locate the phone address immediately, from the IP address it is still hard to find a physical address. Regular phones pay every month extra for 911 service. Since this one doesn't pay any bill, you don't get this service either. As a result, a cell phone at home is still necessary to work as a backup.

If all these have convinced you, you can keep reading the rest of the same label posts, and start investing your research time on it.