The S-GW operator policy provides mechanisms to fine tune the behavior for subsets of subscribers. It also can be used to control the behavior of visiting subscribers in roaming scenarios by enforcing roaming agreements and providing a measure of local protection against foreign subscribers.

The S-GW uses operator policy in the SGW service configuration to control the accounting mode. The default accounting mode is GTPP, but RADIUS/Diameter and none are options. The accounting mode value from the call control profile overrides the value configured in SGW service. If the accounting context is not configured in the call control profile, it is taken from SGW service. If the SGW service does not have the relevant configuration, the current context or default GTPP group is assumed.

Call control profiles are configured with commands in the Call Control Profile configuration mode. A single call control profile can be associated with multiple operator policies

An APN profile groups a set of access point name (APN)-specific parameters that may be applicable to one or more APNs. When a subscriber requests an APN that has been identified in a selected operator policy, the parameter values configured in the associated APN profile will be applied.

APN profiles are configured with commands in the APN Profile configuration mode. A single APN profile can be associated with multiple operator policies.

The IMEI is a unique international mobile equipment identity number assigned by the manufacturer that is used by the network to identify valid devices. The IMEI has no relationship to the subscriber.

IMEI profiles are configured with commands in the IMEI Profile configuration mode. A single IMEI profile can be associated with multiple operator policies.

APN remap tables allow an operator to override an APN specified by a user, or the APN selected during the normal APN selection procedure, as specified by 3GPP TS 23.060. This atypical level of control enables operators to deal with situations such as:

• An APN is provided in the Activation Request that does not match with any of the subscribed APNs either a different APN was entered or the APN could have been misspelled. In such situations, the SGSN would reject the Activation Request. It is possible to correct the APN, creating a valid name so that the Activation Request is not rejected.

• In some cases, an operator might want to force certain devices/users to use a specific APN. For example, all iPhone4 users may need to be directed to a specific APN. In such situations, the operator needs to be able to override the selected APN.

An APN remap table group is a set of APN-handling configurations that may be applicable to one or more subscribers. When a subscriber requests an APN that has been identified in a selected operator policy, the parameter values configured in the associated APN remap table will be applied. For example, an APN remap table allows configuration of the following:

• APN aliasing - maps incoming APN to a different APN based on partial string match (MME and SGSN) or matching charging characteristic (MME and SGSN).

• Wildcard APN - allows APN to be provided by the SGSN when wildcard subscription is present and the user has not requested an APN.

• Default APN - allows a configured default APN to be used when the requested APN cannot be used for example, the APN is not part of the HLR subscription. In 21.4 and later releases, the configuration to enable default APN on failure of DNS query is enhanced to support S4-SGSN. When wildcard APN is received in subscription, the DNS request is tried with the MS requested APN and on failure of DNS, it is retried with the APN value configured in the APN remap table.

APN remap tables are configured with commands in the APN Remap Table configuration mode. A single APN remap table can be associated with multiple operator policies, but an operator policy can only be associated with a single APN remap table.

For planning purposes, based on the system configuration, type of packet processing cards, type of network (2G, 3G, 4G, LTE), and/or application configuration (single, combo, dual access), the following APN remap table configuration rules should be considered:

• 1 - maximum number of APN remap tables that can be associated with an operator policy.

• 1000 - maximum number of APN remap tables per system (such as an SGSN).

• 100 - maximum remap entries per APN remap table.

The profiles and tables are created and defined within their own configuration modes to generate sets of rules and instructions that can be reused and assigned to multiple policies. An operator policy binds the various configuration components together. It associates APNs, with APN profiles, with an APN remap table, with a call control profile, and/or an IMEI profile (SGSN only) and associates all the components with filtering ranges of IMSIs.

In this manner, an operator policy manages the application of rules governing the services, facilities, and privileges available to subscribers.

Operator policies are configured and the associations are defined via the commands in the Operator Policy configuration mode.

The IMSI ranges are configured with the command in the SGSN-Global configuration mode.

Ranges of international mobile subscriber identity (IMSI) numbers, the unique number identifying a subscriber, are associated with the operator policies and used as the initial filter to determine whether or not any operator policy would be applied to a call. The range configurations are defined by the MNC, MCC, a range of MSINs, and optionally the PLMN ID. The IMSI ranges must be associated with a specific operator policy.

IMSI ranges are defined differently for each product supporting the operator policy feature.

This section provides the configuration example to create a call control profile and enter the configuration mode.

Use the call control profile commands to define call handling rules that will be applied via an operator policy. Only one call control profile can be associated with an operator policy, so it is necessary to use (and repeat as necessary) the range of commands in this mode to ensure call-handling is sufficiently managed.

This section provides the configuration example to create an APN profile and enter the apn-profile configuration mode.

Use the apn-profile commands to define how calls are to be handled when the requests include an APN. More than one APN profile can be associated with an operator policy.

The example below includes some of the more commonly configured profile parameters with sample variables that you will replace with your own values.

configure
   apn-profile profile_name
      gateway-address 123.123.123.1 priority 1(SGSN only)
      direct-tunnel not-permitted-by-ggsn (SGSN only)
      idle-mode-acl ipv4 access-group station7 (S-GW only)
      end

This section provides the configuration example to create an IMEI profile and enter the imei-profile configuration mode.

Use the imei-profile commands to define how calls are to be handled when the requests include an IMEI in the defined IMEI range. More than one IMEI profile can be associated with an operator policy.

The example below includes some of the more commonly configured profile parameters with sample variables that you will replace with your own values.

configure
   imei-profile profile_name
      ggsn-address 211.211.123.3
      direct-tunnel not-permitted-by-ggsn (SGSN only)
      associate apn-remap-table remap1
      end

This section provides the configuration example to create an APN remap table and enter the apn-remap-table configuration mode.

Use the apn-remap-table commands to define how APNs are to be handled when the requests either do or do not include an APN.

The example below includes some of the more commonly configured profile parameters with sample variables that you will replace with your own values.

configure
   apn-remap-table table_name
      apn-selection-default first-in-subscription
      wildcard-apn pdp-type ipv4 network-identifier apn_net_id
      blank-apn network-identifier apn_net_id (SGSN only)
      end

This section provides the configuration example to create an operator policy and enter the operator policy configuration mode.

Use the commands in this mode to associate profiles with the policy, to define and associate APNs with the policy, and to define and associate IMEI ranges. Note: IMEI ranges are supported for SGSN only.

The example below includes sample variable that you will replace with your own values.

configure
   operator-policy policy_name
      associate call-control-profile profile_name
      apn network-identifier apn-net-id_1 apn-profile apn_profile_name_1
      apn network-identifier apn-net-id_2 apn-profile apn_profile_name_1 
      imei range <imei_number to imei_number imei-profile name profile_name 
      associate apn-remap-table table_name
      end

This section provides IMSI range configuration examples for each of the products that support operator policy functionality.

After configuring the various components of an operator policy, each component must be associated with the other components and, ultimately, with a network service.

The MME service associates itself with a subscriber map. From the subscriber map, which also contains the IMSI ranges, operator policies are accessed. From the operator policy, APN remap tables and call control profiles are accessed.

Use the following example to configure operator policy component associations:

configure
   operator-policy name
      associate apn-remap-table table_name
      associate call-control-profile profile_name
      exit
   lte-policy
      subscriber-map name
         precedence match-criteria all operator-policy-name policy_name
         exit
      exit
   context mme_context_name
      mme-service mme_svc_name
         associate subscriber-map name
         end

The accounting mode command configures the mode to be used for the S-GW service for accounting, either GTPP (default), RADIUS/Diameter, or None.

Use the following example to change the S-GW accounting mode from GTPP (the default) to RADIUS/Diameter:

configure
   context sgw_context_name
      sgw-service sgw_srv_name
         accounting mode radius-diameter
         end