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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,
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
Table 1 shows some examples of ALR routing.
Table 1 - Types of ALR |
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Type of ALR | Used for |
ALR for HLRs | HLR routing |
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ALR for SMSCs | SMSC routing |
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ALR for VMSs | VMS routing |
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ALR routing locates and routes customer service queries, facilitating communication across the network to all wireless service nodes.
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