h1. LNP/MNP information

{{>toc}}

*LNP/MNP* (*Local number portability/Mobile number portability*) -  see [[Number portability]].

*LNP/MNP information service* - informational service, which is provided by a number of suppliers.
To use this service, customer sends a query to a supplier of LNP/MNP information.
Query contains E.164 subscriber's number of interest.
In response, LNP/MNP supplier sends information data for this number, such as:

* *LRN* (*Location routing number*) of a subscriber.
  If *NPDI* = yes, then this number should be used for call [[Routing]] and [[Billing]] instead of E.164 subscriber's number that is present in signaling.
  If *LRN* is empty, then it means, that E.164 subscriber's number should be used for call [[Routing]] and [[Billing]].
* *NPDI* (*Network protocol dip indicator*) - indicates whether LNP/MNP database has been successfully queried.
  Can be: *yes* - LNP/MNP database has been successfully queried and *LRN* contains valid number, *no* - LNP/MNP database query hasn't been performed and *LRN* doesn't contain valid number
* etc

The contains of LNP/MNP response can vary depending on:

* supplier
* tariff plan chosen by customer.
  For example, more information in LNP/MNP response could cost additional money at the same provider.

To generate response, LNP/MNP information provider could appeal to:

* directly to mobile operators
* to centralized database of LNP/MNP information
* to his local database, in which results of previous queries are cached
* to his local database, which has been replicated from database of other LNP/MNP information suppliers
* to other LNP/MNP information suppliers

As far as LNP/MNP information constantly changes due to [[Number portability]], the source of data greatly influences the freshness of information and the response latency.
Also price may depend on a source of information which is used by LNP/MNP information provider.
Obviously, direct query to mobile operators will cost more that lookup in local database.

*Smartswitch* can act both as supplicant and supplier of LNP/MNP information, see section [[LNP/MNP query]].

After getting response for LNP/MNP query from LNP/MNP provider, *Smartswitch* stores it into [[LNP/MNP cache]].

h2. LNP/MNP information inside a call.

LNP/MNP information could be present inside a call from originator.
For example, you can get a cal with B-number of 380973301330;rn=380504440444;npdi=yes.
This means, that your originator has already performed [[LNP/MNP query]] (because of npdi=yes) and got *LRN* 380504440444.
Depending on the level of your trust to a partner, you can trust this information and perform [[Billing]] on a number 380504440444 instead of 380973301330, or perform LNP/MNP query to your LNP/MNP information providers by yourself.
This behavior is controlled by an option *trust LRN* in originator's settings.
When trusting LNP/MNP information from your partner, you can save your funds, because you don't perform LNP/MNP queries by yourself.

Similarly, you can send LNP/MNP information to your partner to assure he will generate correct invoice to you and to save him from spending funds on LNP/MNP queries.
This behavior is controlled by option *send LRN* in terminator's settings.

[[LNP/MNP информация|Русский перевод]]