Riverstone Networks SSG manual Number Pooling feature provides for

Models: SSG

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Number Pooling

Local exchange carriers require a central office (CO) code per rate center. As a result, there is an increasing incidence of CO code exhaustion requiring the associated numbering plan area (NPA) splits and overlays. Currently, the CO codes, NPA-NXX, are assigned to carriers at the 10,000-block level. At this level, the telephone number utilization tends to be inefficient in sparsely populated rate centers or in switches that do not have many subscribers. As a result, area codes are split even though numbers remain unused. The goal of Number Pooling is to promote better number utilization, thereby avoiding additional area code splits. Number Pooling addresses this use by using 1000-block- level Number Pooling to avoid NPA splits.

The Number Pooling feature provides for

the assignment of numbers in blocks of 1,000. These 1,000 numbers are considered pooled. The owner of the 1,000 number block is called

the block holder, and the owner of the NPA- NXX is called the code holder. A code holder surrenders unused blocks to the pool, which may then be assigned to another service provider. The service provider owning the block assigns a location routing number (LRN) for all numbers within that block. The LRN is used to route the call to the service provider (destination). Any number within a pooled block can port to another service provider. Therefore, any given 10-digit telephone number can be ported, pooled, both ported and pooled, or neither ported nor pooled.

Table 1 shows some examples of ALR routing.

Table 1 - Types of ALR

 

 

 

Type of ALR

Used for

ALR for HLRs

HLR routing

 

 

ALR for SMSCs

SMSC routing

 

 

ALR for VMSs

VMS routing

 

 

ALR routing locates and routes customer service queries, facilitating communication across the network to all wireless service nodes.

A L C AT E L 5 >

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Riverstone Networks SSG manual Number Pooling feature provides for, Shows some examples of ALR routing