RE: call back and call thru pin |
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Zitat: |
Originally posted by SIP
Can any one give a practical senrio of how those things work.
how can i get used of them? |
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Sure. Depending on what country you are in, you can save a bundle on cellphone calls. Let me give you a couple of scenarios.
I'm an American. I live in Dubai and visit the UK for business a great deal. I have mobile phones in all three countries. My US mobile is a contract mobile with free call forwarding to landlines and itnernational Blackberry service with no roaming for Blackberry. I'll get to the relevancy of this in a few minutes.
For a great deal of client work, my partners and I do not always want the client to know that I am out of town. Because of my free call forwarding, I send calls through an Asterisk server to Lichtenstein
In addition to my US phone, I have a UK mobile, a UAE mobile, and a roaming SIM ("Riiing") from United Mobile in LIchtenstein (www.riiing.com). Riiing provides "free incoming calls" in 80 countries including Western Europe and the United Arab Emirates. (Riing charges a fortune for use in the US). I have found a reliable connection which passes caller-id information to riiing from the US. I've programmed Asterisk to answer the phone, play US ringtones and connect the person to me. So far, I have not answered your question.
When I need to originate a call, I get an e-mail in Blackberry. I use the Blackberry to call my callback number which triggers a callback to my Riiing SIM. (In the UAE, I use my Dubai SIM for the same purpose and unfortunately, yes, sometimes I carry two mobiles plus a Blackberry).
I pay US$0.11 for this callback and connection to anyone in the US and most of Western Europe. Because the call is routed through Asterisks, the outbound call will either project my US cellphone number or my office number depending on what the case might be. I also have full access to my Asterisk server. I can retrieve voicemail, transfer calls, park calls, etc. I have full access to my system.
In the UK, Canada, and the US, I have local dialin numbers which means that I dial my IVR, punch in a hidden extension, get a dialtone plus full access to my system. Again free calls.
While I travel more than many, even on the domestic front, a callback or call through service can save a great deal of money. Nerdvittles.com has a good example of how to turn a cheap US cellphone plan into an unlimited calling plan using a similar technique.
For Yanks and Kunucks, here is another. Many mobile plans in those countries offer free mobile to mobile calls. Several companies offer unlimited call forwarding as an option on their plans and permit you to add a second handset to your plan for about US$10 a month. Add in the unlimited call forwarding and here is what you do. Get a second phone with call forwarding. Pick up a free US DID from stanaphone.com, ipkall, or sipphone.com. Call forward your mobile to the DID and have it ring into a box with voicemail and caller-id authentication. If someone else calls the number, they hear: "this john doe. I'm out. Leave a message." You'll just get a second dialtone and unlimited calls.
A small number of North American carriers offer free incoming calls. Europeans might ask why this is such a big deal. The answer is because North American carriers use regular phone numbers, not higher priced mobile exchanges. A callback system on one of these systems with two unlimited numbers means unlimited mobiles. It also means a completely portable versioin of your PBX system that you can take anywhere.
These features are great. On this system (which gets better each day), I only wish that you could exit out of functions back to a dialtone without having to do a new callback or dial-in.
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