In the CCITT International X.121 format , the first four digits of the international data number, the three digits that may represent the data country code , and the 1-digit network code, i.e. , the network digit .
DATA NETWORK IDENTIFICATION CODE (DNIC)
Meaning of DATA NETWORK IDENTIFICATION CODE (DNIC) in English
Telecommunication standard terms English vocab. Английский словарь стандартных телекоммуникационных терминов. 2012