Wednesday, August 1, 2007

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.

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