The external call transfer – is the call transfer to a telephone line other than the company’s telephone line. The internal call transfer – the transfer of an incoming call to another addressee registered on the same telephone line.
Rates of the call shop are usually defined by the administrator, but the rate plans are managed in the main database of the billing system. All the rates are dependent on the charging policy; in case of a destination based billing rates are specified according to the area codes in the supported destinations.