A Foreign PLMN GUTI Management Database is configured as part of the LTE Policy configuration mode.

config
   lte-policy
      foreign-plmn-guti-mgmt-db fguti_db_name
      end

Up to four Foreign PLMN GUTI Management Databases can be configured.

To delete an existing database, in the lte-policy mode include the no prefix with the command. You need to identify the database to be deleted.

no foreign-plmn-guti-mgmt-db fguti-db1

A Foreign PLMN GUTI Management Database entry consists of an MCC, an MNC, and an action (either Allow or Reject). The following example creates two entries:

configure
   lte-policy
      foreign-plmn-guti-mgmt-dbdb_name
         plmn mcc 123 mnc 456 allow
         plmn mcc 321 mnc 654 reject
         end

The any keyword may be used as a wildcard in place of both the MCC and MNC values, or in place of an MNC value with a specific MCC value. In other words, the following commands are allowed:

plmn mcc 123 mnc any allow
plmn mcc any mnc any reject

However, a wildcard MCC is not allowed with a specific MNC value. For example, the following command is not allowed:

plmn mcc any mnc 456 allow

It is strongly recommended that a Foreign PLMN GUTI Management Database contain an mcc any mnc any entry in order to define the default behavior when a GUTI with an unknown MCC / MNC combination is received. If such an entry is absent, the default behavior will be to allow Attach Requests and TAU Requests with unknown MCC/ MNC combinations, which may result in DNS lookups for peer MMEs and SGSNs. This default behavior would be the same as if there were no Foreign PLMN GUTI Management Database defined.

Up to 16 foreign PLMN entries can be added to a database.

The no prefix followed by a PLMN ID removes a specific entry from the database. Refer to the following example:

no plmn mcc 123 mnc 456

An MME Service can be associated with a database using the associate foreign-plmn-guti-mgmt-db command in MME Service Configuration mode.

configure
   context  ctxt_name
      mme-service  mme_svc
         associate foreign-plmn-guti-mgmt-db  db_name
         end

Multiple MME Services may be associated with a single Foreign PLMN GUTI Management Database. Because of this, it is not possible to cross-check the PLMNs in the database against an MME Service's own PLMN or its shared PLMNs. However, the MME Service's own PLMN or shared PLMNs will never be checked against the Foreign PLMN GUTI Management Database, regardless of whether those PLMNs are configured in the database or not. In other words, any Attach Request or TAU Request containing a GUTI from the MME Service's own PLMN or one of its shared PLMNs will always be processed, and may result in a DNS lookup for a peer MME or SGSN.

The association can be removed using the following command:

no associate foreign-plmn-guti-mgmt-db

Use the following command to display the list of Foreign PLMN GUTI Management databases configured on the system:

show lte-policy foreign-plmn-guti-mgmt-db summary

Use the following command to display the entries configured within a specific Foreign PLMN GUTI Management Database:

show lte-policy foreign-plmn-guti-mgmt-db name fguti-db1
Foreign PLMN GUTI Mgmt DB fguti-db1    
        PLMN mcc 123 mnc 456 allow
        PLMN mcc 321 mnc 654 reject
        PLMN mcc any mnc any reject
        PLMN mcc 123 mnc any allow

Use the following command to display the Foreign PLMN GUTI Management database to which an MME Service has been associated:

show mme-service name mme_svc_name

Refer to the Foreign-PLMN-GUTI-Mgmt-DB field in the output, as shown here:

Foreign-PLMN-GUTI-Mgmt-DB            : fguti-db1

This section provides information regarding show commands and/or their outputs relating to this feature.

MME Schema

The following statistic is included in the MME Schema in support of the Foreign PLMN GUTI feature:

This statistic increments when an Attach or TAU request containing a foreign GUTI is rejected due to restrictions set in the Foreign PLMN GUTI Management Database.

System Schema

The following statistic is also included in the System Schema in support of the Foreign PLMN GUTI feature:

This statistic increments when a session is disconnected due to the restrictions set in the Foreign PLMN GUTI Management Database.