MCCMNC Configuration

The Diameter Common > Network Identifiers > MCCMNC pages are used to configure up to 2500 distinct combinations of Mobile Country Code (MCC) and Mobile Network Code (MNC).

The configured MCCMNC entries can be mapped to Diameter Realms, MSISDN prefix digits, and CC+NDC combinations, using the Diameter Common > Network Identifiers > MCCMNC Mapping page (see MCCMNC Mapping Configuration).

MCCMNC combinations are used by Address resolution applications like Full Address Based Resolution (FABR) and Range Based Address Resolution (RBAR), which need to categorize User Identities (digit strings) decoded from the Diameter Request AVPs as either MSISDN or IMSI, to allow looking up the User Identity in the appropriate lookup table.

Most of the time, these applications can clearly categorize the decoded User Identity based on:

The configured Routing Entity Type
The contents of the AVP
For instance, if the User Identity has been decoded from a SIP URI that has a "+" sign before the digits (such as sig:+1-919-460-5500@oracle.com), it can be directly categorized as an MSISDN.
The number of digits in the User Identity

In certain cases, none of these methods allow a clear categorization (for example, if the number of digits needs to be used and the received number of digits are applicable to both IMSIs and MSISDNs, and thus leads to an ambiguous determination; or if there is no ""+" sign before the digits). In such cases, a tie breaker procedure is required to categorize the digits as an IMSI or an MSISDN. The configured MCCMNC combinations can be used to provide a tie breaker mechanism in such cases, as follows:

If FABR has been configured to decode an IMPU from a User Identity (digit string) but cannot determine whether the User Identity is an IMSI or an MSISDN based on digit analysis, FABR needs a tie breaker to categorize the User Identity properly.
FABR extracts the first 5 or 6 digits of the User Identity and compares them against the list of configured 5-digit and 6-digit MCC-MNC combinations on the Diameter Common > Network Identifiers > MCCMNC page.

If a match occurs, the User Identity is considered to be an IMSI and is used for an IMSI lookup.

If a match does not occur, the User Identity is considered to be an MSISDN and is used for an MSISDN lookup.
If RBAR has been configured to decode an IMPU/MSISDN from a User Identity (digit string) but cannot determine whether the User Identity is an IMSI or an MSISDN based on digit analysis, RBAR needs a tie breaker to categorize the user identity properly.
RBAR extracts the first 5 or 6 digits of the User Identity and compares them against the list of configured 5-digit and 6-digit MCC-MNC combinations on the Diameter Common > Network Identifiers > MCCMNC page.

If a match occurs, the User Identity is considered to be an IMSI. RBAR will bypass the AVP; as RBAR does not support decoding an IMSI from a Routing Entity of IMPU or MSISDN.

If a match does not occur, the User Identity is considered to be an MSISDN and is used for MSISDN lookup.

As described in MCCMNC Mapping Configuration, MCCMNC combinations and MCCMNC Mapping are used by:

The MAP-Diameter Interworking Function to translate a Diameter Request message to a MAP Request message (ITU) or a MAP Request message to a Diameter Request message.
Diameter Mediation to populate the Destination-Realm AVP based on the IMSI value present in a Request message.

On the Diameter Common > Network Identifiers > MCCMNC page, you can perform the following actions:

Filter the list of entries, to display only the desired entries.
Sort the list entries in ascending or descending order by by clicking the column heading. By default, the list is sorted by MCC and MNC in ascending ASCII order.
Click Insert.

The Diameter Common > Network Identifiers > MCCMNC [Insert] page opens. You can add new MCCMNC entries. If the maximum number of MCCMNC entries (2500) already exists in the system, the Diameter Common > Network Identifiers > MCCMNC [Insert] page will not open, and an error message is displayed.
Select an MCCMNC entry in the list, and click Edit.
The Diameter Common > Network Identifiers > MCCMNC [Edit] page opens. The selected MCCMNC entry can be edited.
Select an MCCMNC entry in the list, and click Delete to remove the selected entry.