PBX Phone System

A phone numbering plan is a plan used to allocate international telephone numbers between different continents and cities and among mobile phone networks. It’s still not right to confuse international calling codes with numbering plans. In regions like Australia or Canada there appears a closed numbering plan which supposes special length territory codes and telephone numbers.

The so-called open numbering plan supposes that phone numbers and calling codes can differ according to the country and district they are located in. The plan works in many countries nowadays. The numbers defined by the open plan are dialed variously. You should know which units are to be anyway dialed (they complete the local phone number) and which may be missed (area calling codes).
It seems really much difficult to unify the rules. Though the International Telecommunication Union (ITU) tried to introduce common rules of numbering plans and international dialing codes, they still are different in different lands. E.g. double zero was supposed to serve as an international code of access. Some nations have agreed to the offer and entered the combination, but as changing the combination was not compulsory for the state members in some of them like the USA the dialling codes stayed as they used to be. Missed the idea? Give a try to new reverse phone look up!

According to the international numbering plan country calling codes are assigned. Country code stands for a country or a number of countries. The E.164 standard serves exactly for regulating country calling codes at the international level. It sets the general size of a complete international phone number. It happens so that in every region the phone numbers are fixed differently by local standards. District area codes then can exist with:

- Defined standards of the calling code that includes several digits like three in USA or 1 in Australia.
- Indefinite dialling code norms. So in regions like Austria or Argentina the code varies between 2 and 5, on japanese isles – between 1 and five and in Peru and Syria the code contains from one to two digits.

- The dialing code incorporated into the number itself. It’s popular in several regions like Norway and Spain. This way the closed numbering plan is applied. It happens that interurban area dialing codes are popular in countries like Italy, the Netherlands, South Africa etc. And generally for this purpose 0 is applied.

The calling code of the region mainly enables to charge the subscriber for calls the right way. As a rule making calls on the numbers within local calling code is much less expensive than making calls on the phone numbers with some other area calling code.

Still as in States the rates for home calls are assigned by the state norms while trunk-line calls are defined by competition, it happens so that home calls seem to be less cheap.

As sometimes in States the interval between the callers of one large location may be too long, the calls are charged considering the interval though the area dialing code is the same.

Rate centers usually define the prices, which are assigned for sections from zero to six miles, from 6 to 12, and bigger zones. But it became different with the end of regulation of local call services.

It’s now going popular among the people to take the so-called all-you-can-eat plan (an assigned rate of nearly thirty dollars monthly as actual for spring 2008 giving an opportunity to reach any place of the USA).
In several areas mobile phone systems use special area dialling codes. As well the codes are applied for some exceptional rates, free or premium accounts.

There as well can be various particular circumstances. E.g. in areas like Egypt dialling code define nothing because the costs are similar for the whole territory and in Great Britain the area dialling code is made of 2 segments each with its rate.