X400: Definition of X.121 Address (86977)

SUMMARY

The X.121 is an address that enables packets to be sent to people on a public data network. The X.25 network uses X.121 addresses to determine routing within the X.25 network.

The X.121 address can be equated to a voice phone number on a telephone network.

The X.121 address length for an international data number is a 10-digit numeric character set from 0 to 9. The number formats for various data accesses are as follows:

International data number:

P + DNIC + NTN

Or, if the number is part of a national integrated numbering scheme:

P + DCC + National Number

Public telephone network:

P + 9 + TCC + National Significant Telephone Number

Public Telex network

P + 8 + TDC + National Telex Number

Here are descriptions of the acronyms used above:

   Acronym   Description
   -------   -----------

   DCC       Data country code (3 digits)
   DNIC      Data network identification code (4 digits)
   NTN       Network terminal number)
   P         International prefix
   TCC       Telephone country code
   TDC       Telex destination code

For more information, refer to CCITT Recommendation X.121 Fascicle VIII.4.