Glossary - N


National Directory Enquiry Service

This is a Directory Enquiry Service that provides information on the allocation of numbers to different subscribers from the United Kingdom numbering scheme to all callers located in the United Kingdom. The National Directory Enquiry Service should be considered a "full" National Directory Enquiry Service (at least for the time being) if it provides information on geographic numbers (those numbers starting with the digits 01 or 02) of all the business and residential listings and also on other numbers that are used for relatable purposes to geographical numbers (for example, 08 numbers used for main switchboards etc). NB. this is only the case where the subject of the listing does not withhold their permission for its inclusion.

National Numbering Scheme

This is a scheme aimed at the allocation and re-allocation of numbers that are specified by the Director General and have been made available by him for their public inspection.

National rate

This is the rate for calls that are within the national call area. The area is defined by the telecommunications operator that is serving the customer.

National Regulatory Authority (NRA)

This is the body or bodies, that are legally distinct and functionally independent from the telecommunications organisations. They are charged by a Member State with the supervision of, elaboration of and compliance with, the telecoms authorisations.


Network channel terminating equipment.


A network exists as a collection of computers that are all linked together in order to share data. They are classified according to their geographical extent: LANs (local area network) may be interconnected through WANs (wide area network) connections.


Network interface card.


National Institute of Standards and Technology.


Network interface.


Network operations center.

Non-Geographic Number

These are numbers that are used in order to identify a type of service as opposed to a geographical location. Sometimes these services are known as Specially Tariffed Services and may include freephone, national rate, local rate and premium rate numbers. Personal and Mobile numbers are alos non geographic numbers.

Non-Geographic Number Portability

Where a customer who has been allocated a non-geographic number that is associated with a particular service, for example an 0800 freephone, an 090 premium rate number, or an 07 personal number, can actually retain that number when they change to a different service provider or operator who offers a service of a similar or same type.


Network operating system.


Numbering plan area.


Network termination.


See Network Termination Point.


See Number Translation Services.

Number block

This is a means of distributing numbers to network operators who , in trun, allocate individual numbers to customers. Block sizes for the different sections of the Specified Numbering Scheme become identified in groups known as Numbering Conventions.

Number Block Portability

This is the facility that enables a customer to transfer there number block (or a series of numbers form within their number block) from one operator to another.

Numbering Conventions

These are a set of rules and principles that relate to the use and management of National Numbering Scheme numbers. Numbering Conventions are also published on Oftel’s Internet pages.

Number mobility

This is the ability to move a geographic telephone number when changing address.

Number portability

Number portability operates between operators and enables a customer to transfer their number from one operator to a another operator (this is under the proviso thatthe customer continues to remains at the same address).

Number Portability Prefix Codes

These are codes that are allocated from the Numbering Scheme and are used for the internal routing of numbers that have been ported. In other words a prefix is attatched to the number that is dialled, and this prefix specifies the exchange (operator) to where the number has been ported.

Number translation

This is a service in which a dialled number is translated onwards to another number for final delivery for example 0800 numbers.

Number Translation Services (NTS)

These are telephone services that use non-geographic numbers. The number is then translated to a mobile or geographic number for its final delivery to the party that has been called.

Numbering Code

These are the initial dialled digits of a phone number that identify the service.

Numbering Scheme

This is a scheme that exists to enable the allocation and consequently re-allocation of numbers, prefixesand codes. This 'Numbering Scheme' specifies the number ranges that are allocated and for which type of telephony service. This encompasses all the public numbering capacity available from the number ranges 01 to 09 and includes access and other codes and prefixes.


© Global Telecom 2005 | Legal Notice.
Contact Details Enquiry Form