International Network Identification Codes Notification Form
Assignment of International Network Identification Codes for Public Frame Relay Data Networks and ATM networks numbered under the E.164 numbering plan (According to ITU-T Recommendation X.125 (09/98))
Public Frame Relay Data Networks may be numbered under either the X.121 numbering plan or under the E.164 numbering plan. The default numbering plan for public ATM Networks is the E.164 numbering plan.
Codes identifying networks are required for use within the Frame Relay and ATM signalling protocols in order to support network features such as transit network identification, transit network selection, closed user group interlock codes and clearing network identification.
For networks numbered under the X.121 numbering plan, the Data Network Identification Codes (DNICs) provide the network identification capability as part of the structure of X.121 numbers. For networks numbered under the E.164 numbering plan, the network identification capability cannot be based solely on the structure of E.164 numbers.
It is not mandatory that an E.164 number be structured to specifically identify a particular network within the domain of a particular country code. In most cases, the E.164 number structure does not identify a specific network, and accordingly the need to accommodate network identification can not be based solely on the structure of the E.164 numbers. To overcome this problem, a protocol specific mechanism has been defined within the Frame Relay interface specifications (X.36 and X.76) in order to uniquely identify a particular Public Frame Relay Data Network which may be numbered under the E.164 numbering plan. Likewise, mechanisms in ATM signalling and OAM procedures are available to identify a specific ATM Network.
When used in conjunction with the E.164 Country Code, these network identifiers provide the ability to uniquely identify (on a global basis) a particular Public Frame Relay Data Network or ATM Network. The network identifiers are contained within a specific field of the signalling protocol and do not impact on the structure of E.164 numbers and require no modification to national E.164 numbering plan.
The International Network Identification Code consists of the E.164 Country Code followed by a national network identifier. The maximum length of the International Network Identification Code is 8 digits.
Assignment and notification procedure
The allocation and registration procedures for national network identifiers are seen to be a national matter. However, regular publication of such information is required to be made available to both users and operators of Public Frame Relay Data Networks and ATM Networks for the effective operation of specific network features. A procedure for the notification to the ITU/TSB of International Network Identifier Codes, following the assignment by a national authority of national network identifiers, has been defined within Recommendation X.125 in order that this information can be maintained in a central register and be published on a regular basis. The ITU/TSB will maintain a list of allocated International Network Identification Codes and regularly publish the information in the ITU Operational Bulletin.
Administrations are then requested to inform the ITU/TSB of any assignment by a national authority of national network identifiers by using the notification form contained in Annex A to Recommendation X.125.