In this section:
This feature helps simplify the modification command to set Destination-Realm AVP from international mobile subscriber identity (ISMI) numbers. For more information about modification commands, refer to Configuring Modification Commands.
There are three components within the IMSI:
Mobile Network Code (MNC)
The MNC is a unique number to identify the mobile subscriber network and is assigned by the government of each country.
Depending on the country of origin, the MNC can be either two or three numbers long.
The feature uses two of the IMSI components, MCC and MNC, within the AVP portion of the AVPAlias command to modify the Destination-Realm AVP value.
The MCCMNC table is populated with default values from http://www.mcc-mnc.com/ to cover the MCCMNC values that have 3-digit MNC values. The MCCMNC values are stored as sequence search structure strings. The strings are searched longest from left to check if the MCCMNC values from the IMSI can be found in the MCCMNC table.
When the MCC value has MNC values that are all 3-digits, they are grouped in the table as one entry as the MCC value.
When a match is found, the length of the match is used to determine the length of the MNC.
The match result is used to break the IMSI AVP string value to MCC and MNC substrings used to modify the Destination-Realm AVP value.
After the required IMSI Mobile Codes have been configured, you can create a Modification Table with the following commands:
For detailed information on how to configure a Modification Table, refer to Configuring Modification Tables and Records.
replace-dest-realm-from-imsi-if <AVPAlias> <Destination-Realm> <empty> <optional suffix=3gppnetwork.org>
When the Diameter traffic hits a modification table with the command replace-dest-realm-from-imsi or replace-dest-realm-from-imsi-if, the following occurs:
The first 6-digits are retrieved from the IMSI and looked up in the MCCMNC table, longest from left.
If the MNC is 2-digits long, then a zero is appended to the beginning of the MNC to make it 3-digits long.
For more detailed information about the modification commands, refer to Configuring Modification Commands.