Hi,

A numbering  plan identifies each VoIP endpoint and application in the network with a unique  telephone number. Numbering plan design should evaluate both current  requirements and potential growth requirements to avoid the need to renumber as  more users connect to the voice network. There are diffrent types of numbering plans like E.164 plan(International public numbering plan),national numbering plans and private numbering plans. More of this can be read at the link below

http://ciscoarticles.com/Voice-Over-IP/721.html

As far as the number type is concerned, every subscriber in a mobile network is uniquely  identified by a mobile station ISDN or public switched telephone network  (PSTN) number. The type of Number(TON) is used for many purposes, one of which is for billing the end users.

The TON information is displayed as an attribute-value (AV) pair in the  AAA accounting records that are sent to the RADIUS server for billing purposes. The format  is as follows:

caller-type-of-number=value

The value can be any of the following, which are specified in the  International Telecommunication Union Telecommunication Standardization  Sector (ITU-T) specification Q.931 dated March 1993.

•National—refer to ITU-T Recommendation I.330

•International—refer to ITU-T Recommendation I.330

•Subscriber (local)—refer to ITU-T Recommendation I.330

•Network  specific—an administrative or service number that is specific to the  serving network (for example, a number used to access an operator)

•Unknown—the user or the network has no knowledge of the type of number.

HTH

Regards

Nitesh

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