B TIF Number Substitution Relationships
This chapter includes information to support the TIF Number Substitution feature (TIF NS).
TIF Number Substitution Relationships
The TIF Number Substitution (TIF NS) feature enables subscriber DN records to associate with DNs and DN Blocks for TIF Number Substitution. All DNs and DN Blocks used for TIF NS shall be provisioned as public or private.
Two types of substitutions are supported:
-
Public has Private Number: A DN or DN Block substitutes to (points to) a DN that is Private. The originating DN or DN Block is Public.
- Private has Public Number: A DN or DN Block substitutes to (points to) a DN that is Public. The originating DN or DN Block is Private.
Two types of cardinality are supported:
- 1-way Substitution: A DN or DN Block points to a DN. An arbitrary number of DNs and DN Blocks can point to the same DN. The pointed to DN points to nobody.
- Subscriber Pair: Two DNs may be linked in a pair. A DN in a TIF NS pair can only point to the DN pointing to it (other DN in pair). No other DNs or DN Blocks may point to either DN in such a pair.
This table shows the combination of associations that are supported and prohibited to subscriber records. The left-most column lists the subscriber record type, and the right columns list its supported and prohibited associations.
Table B-1 Supported and Prohibited Subscriber Associations
| Type | Associations | |||||
|---|---|---|---|---|---|---|
| NSDN | ASD | SP | RN | VMS | GRN | |
|
DN, DN Block |
None | None | Any One | |||
|
DN, DN Block |
None | None | Any Two Unique NE Types (Except SP + RN) | |||
|
DN, DN Block |
Supported | None | Any One | |||
|
DN, DN Block |
None | Supported | Any One | |||
|
DN, DN Block |
Prohibited | Supported | Any Two Unique NE Types (Except SP + RN) | |||
|
DN, DN Block |
Supported | Supported | Any One | |||
| MSISDN | None | None | From IMSI | Prohibited | ||
| MSISDN | Supported | None | From IMSI | Prohibited | ||
| MSISDN | None | Supported | From IMSI | Prohibited | ||
| MSISDN | Supported | Supported | From IMSI | Prohibited | ||
This is a list of rules for TIF NS:
- An arbitrary number of DN and DN Blocks can number substitute to the same DN. This DN, called the NSDN, cannot substitute to anybody. The only exception is called a subscriber pair.
- Subscriber pair: Two DNs that number substitute to each other. Nobody else can number substitute to either DN in this pair.
- DN Blocks can number substitute to a DN. However, nobody can number substitute to a DN Block.
- The default subscriber type is public. If subscriber type st has never been explicitly set on a record, the record is public.
- Only DN and DN Blocks with the public subscriber type can be linked to a private DN through TIF NS. Likewise, only private DN and DN Blocks can linked to a public DN.
- Subscriber type is set when the NSDN is defined and TIF NS is created. It cannot be changed while the TIF NS relationship persists.
- There are two ways a DN or DN Block can be removed from TIF NS.
- Directly, if it has an NSDN. It may be updated with ‘nsdn none’. This is to be performed on each DN in the case of a subscriber pair.
- Indirectly, if it does not have an NSDN. All the DN and DN Blocks that substitute to it have been updated with ‘nsdn none’.
- A DN cannot be deleted while other records refer to it by TIF NS.
- A DN or DN Block with NSDN is limited to having one NE (sp, rn, vms, grn).
- A DN or DN Block with two NE (sp, rn, vms, grn) and ASD, cannot have NSDN. They cannot substitute to another number.