Content Filtering and X-Header Enrichment

• Feature Summary and Revision History, on page 1

• Feature Description, on page 1

• Content Filtering, on page 2

• X-Header Insertion, on page 3

Feature Summary and Revision History

Summary Data

Table 1: Summary Data

SMFApplicable Product(s) or Functional Area

SMIApplicable Platform(s)

Disabled - Configuration RequiredFeature Default Setting

Not ApplicableRelated Changes in this Release

Not ApplicableRelated Documentation

Revision History

Table 2: Revision History

ReleaseRevision Details

Pre-2020.02.0First introduced.

Feature Description

The SMF supports the following functionality:

Content Filtering and X-Header Enrichment

• Content Filtering

• X-header Enrichment

Content Filtering

Feature Description

The Content Filtering (CF) service prevents subscribers from inadvertently getting exposed to universally

unacceptable content, or content that is inappropriate as per subscriber preferences. Based on the URLs in the

subscriber requests, the CF service filters HTTP and WAP requests from mobile subscribers. Operators can

filter and control the content for an individual subscriber to access.

Configuring Content Filtering

This section describes how to configure CF support.

Apart from the following configurations, all other configurations are used only in the UPF, and SMF sends

it to the UPF. The SMF doesn't use these configurations. For more information on how to enable the feature

on UPF, see the UCC 5G UPF Configuration and Administration Guide.

Note

Configuring Content Filtering under Active Charging Service

To configure CF under the active charging service, use the following sample configuration:

config

active-charging service service_name

content-filtering category policy-id cf_policy_id

end

NOTES:

• content-filtering category policy-id cf_policy_id: Specify the CF policy number. cf_policy_id must be

an integer in the range of 1-4294967295.

Configuring Content Filtering under Rulebase

To configure CF under the rulebase, use the following sample configuration:

config

active-charging service service_name

rulebase rulebase_name

content-filtering category policy-id cf_policy_id

end

NOTES:

Content Filtering and X-Header Enrichment

Content Filtering

• content-filtering category policy-id cf_policy_id: Specify the CF policy number. cf_policy_id must be

an integer in the range of 1-4294967295.

Configuring Content Filtering under APN

To configure CF under the APN, use the following sample configuration:

config

apn apn_name

content-filtering category policy-id cf_policy_id

end

NOTES:

• content-filtering category policy-id cf_policy_id: Specify the CF policy number. cf_policy_id must be

an integer in the range of 1-4294967295.

Content Filtering Policy ID on N7 Interface

The CF categories are configured under the active charging service under specific policy IDs. The rulebase

and APN also have an associated policy ID. For any session, one policy ID can be associated with the session

at anytime. The categories configured under that CF policy ID are applicable for the session on the UPF.

The PCF can override the CF policy ID by sending this value on the N7 interface. For this purpose, a proprietary

IE is available in the YAML definition for the N7 interface. The hierarchy for the CF policy ID is as follows:

smPolicyDecision

ciscoAvpSet:

cfPolicyId: uint32 value

When the PCF does not send a CF policy ID, the existing CF policy ID in the rulebase configuration or the

policy ID configured in the APN configuration is selected, in the order of precedence. This CF policy ID

value is sent to the UPF in PFCP Session Establishment Request message in the "Subscriber Parameters"

attribute. During PDU Session Modification, if the PCF changes the CF policy ID, the ID is sent to the UPF

in PFCP Session Modification Request message.

X-Header Insertion

With the X-Header Insertion and X-Header Encryption features, collectively known as Header Enrichment,

you can append headers to HTTP or WSP GET and POST request packets, and HTTP response packets for

use by end applications. For example, mobile advertisement insertion (MSISDN, IMSI, IP address,

user-customizable, and so on).

Supported X-Header Information

Out of all the configurable X-header information, some information requires SMF to send the corresponding

values to the UPF. The following table lists the information that is sent from the SMF to the UPF for X-header

insertion.

Content Filtering and X-Header Enrichment

Configuring Content Filtering under APN

Table 3: X-header Information

Modified in Session

Modification

Present in Session

Establishment

DescriptionXheader Field

——Inserts the configured string in xheaderString Constant

—YesPer Flow or Bearer Charging IdCharging ID

—YesIMEI for the callIMEI

—YesIMSI for the callIMSI

YesYesRAT type for the UE sessionRat-Type

—YesMCC or MNC of the SGW or AMFs-mcc-mnc

YesYesAMF or SGW addressSgsn-address

YesYesUser Location InfoULI

YesYesN4 or or S5 endpoint of SMFGGSN-Address

——MSISDN of the UERadius-station-ID

YesYesRulebase for a callSn-rulebase

——IP address allocated to UESubscriber-ip-address

NoYesObtained from MSISDNMsisdn-no-cc

The subscriber-specific fields—IMSI, MSIDN, and IMEI—are encoded in the "User ID" standard IE. For

more details, see 3GPP 29.244, Section 8.2.101.

Rest of the fields are sent in the "Subscriber Parameters" proprietary AVP. Some fields, such as the "Rulebase"

and "UE IP address", are sent as a part of the created PDRs.

• All the parameters are always sent from the SMF to the UPF irrespective of whether X-header

configuration is available. These parameters ensure that any change in configuration after session creation

is immediately applied on the UPF.

• The SMF supports X-header insertion-related configurations. The SMF does not require these

configurations for its functionality. These configurations are sent to the UPF.

Note

Content Filtering and X-Header Enrichment

Supported X-Header Information