You will need
- Caller ID, Internet.
Call your mobile operator, tell visiteuses room and ask what it is for the region. They are usually willing to give such information.
Enter the phone code in the search engine. This method is not always reliable: the answers refer to different regions that is true, to determine not so easy.
List of country codes is available in Wikipedia. If you enough to know only a country look. But if you want more detailed information, go to the website mtt.ru. Scroll down the page, at the very end, after the questions, there are sections "About the company", "information Disclosure" and other. Select "Reference information".
On the opened page we see the panel menu on the left. Click on "Codes of mobile operators", if you think that it was a call from Russia). Warning: the page is not always loaded completely. If you don't see on the opened page the button "Filter", click "Refresh page" in the top bar of your browser.
In the upper field "Code. DEF" enter the code of the phone from which you called. Other fields to be filled in. Click filter - displays information about the region of Russia, which was made the call, and what digits can begin and end number in this region.
If called from another country, then in the left pane, click on "International and long-distance codes." Again, wait until the boot button, "Filtering" or refresh the page.
The first field on the page ("Country") noise, in the box immediately underneath, write the country code (or area code) and click on the button "Filter". The alternative is find out whether the program in your phone that identifies countries and regions. One of them is Pnone Wizard.