The telephone number that is attached to a country, by dialing which it is necessary to take into account the code of the country or region you are calling to. When dialing the number from the same country you are calling to there is no need to enter the country code, but simply a phone number, sometimes a code of the region, might be a case when calling from one state or region to another, applicable to large counties (USA, Canada, Russia, China etc.).
Opto Network Private Limited is an Internet Telephony Service Provider in India. Head office is in Noida, India, Band having branches in Bangalore and Mumbai.