You can use basic filtering in a GTP profile to allow or deny traffic based on APN, MCC-MNC, mode, and MSISDN. Basic filtering is also called IMSI filtering.
The International Mobile Station Identity (IMSI) is used by a GPRS Support Node (GSN) to identify a mobile station. Three elements make up every IMSI:
- the mobile country code (MCC)
- the mobile network code (MNC)
- the mobile subscriber identification number (MSISDN).
The subscriber's home network—the public land mobile network (PLMN)—is identified by the IMSI prefix, formed by combining the MCC and MNC.