1.6 Number Portability Lookup
A single invocation of NPP can result in multiple invocations of various Service Action Handlers associated with TIF features. Because nearly all TIF Service Action Handlers perform Number Portability lookups, TIF provides a common mechanism to ensure that only a single CdPN or CgPN lookup is done and that the resulting data are shared by all Service Action Handlers.
The CdPN lookup is performed on the conditioned CdPN digit string. The conditioned string is typically in International format.
The CgPN lookup is performed on the conditioned CgPN. The conditioned CgPN is typically in International format.
Interpreting Results of an Number Portability Lookup
The following table lists portability types that are relevant to Number Portability lookups.
Table 1-14 Portability Types Relevant to NP Lookups
| Value | Description |
|---|---|
| 0 | Not known to be ported (available for backward compatibility; 36 should be used instead of 0) |
| 1 | Out-of-network; my subscriber ported out |
| 2 | Out-of-network; foreign subscriber ported in, then ported out |
| 5 | In-network; number migrated from IS41 to GSM |
| 36 | Not known to be ported |
| 0Xff | No status; Indicates “none” in the database |
The following table summarizes the meanings of the normal lookup return codes:
Table 1-15 Possible Lookup Results
| Return Code | Meaning |
|---|---|
| ENTITY FOUND | The DN was found and at least one of the specified entities is present. |
| ENTITY NOT FOUND | The DN was found, but none of the specified entities are present |
| DN NOT FOUND | The DN was not found. |
The general rule for determining portability status is that a subscriber is considered own-network (or in-network) if the entity type is SP, and the subscriber is considered ported out if the entity type is RN. There is a special case that is associated with both the IS41 to GSM migration feature and the Service Portability feature. With both of these features, the case where the network entity type is RN and the portability type is 0 (own network IS41 subscriber), the RN is treated as the SP.
- A subscriber is considered in-network if the entity type is SP
- A subscriber is considered ported out if the entity type is RN. One exception to this rule is the case of subscribers migrated from GSM to IS41. These subscribers are considered IS41 own-network even though the entity type is RN.
The RN, SP, VMSID, and GRN (Generic Routing Number) entity types are supported.
In certain networks, a network an entity type other than RN and SP can affect portability status. For example, an entity type of GRN could imply ported number. This can be indicated by setting the NPTYPENPTYPERLY, NPTYPERLS, or NPTYPECGPN configuration option to ANY or ALL.