This section provides an overview of the X-Header insertion feature.

Extension header (X-Header) fields are fields that are not defined in RFCs or standards but can be added to protocol headers for specific purposes. The X-Header mechanism allows additional entity-header fields to be defined without changing the protocol, but these fields cannot be assumed to be recognizable by the recipient. The unrecognized header fields must be ignored by the recipient and must be forwarded by transparent proxies.

The X-Header insertion feature enables inserting x-headers in HTTP or WSP GET and POST request packets and HTTP response packets. Operators wanting to insert X-headers in HTTP or WSP request and HTTP response packets, can configure rules for it. The charging-action associated with the rules contain the list of X-headers to be inserted in the packets.

This section provides an overview of the X-Header Encryption feature.

X-Header encryption enhances the X-header insertion feature to increase the number of fields that can be inserted, and also enables encrypting the fields before inserting them.

If X-Header insertion has already happened for an IP flow (because of any X-Header format), and if the current charging-action has the first-request-only flag set, X-Header insertion won't happen for that format. If the first-request-only flag is not set in a charging-action, then for that X-Header format, insertion continues happening in other suitable packets of that IP flow.

Changes to X-Header format configuration will not trigger reencryption for existing calls. The changed configuration will however, be applicable for new calls. The changed configuration will also apply at the next reencryption time to those existing calls for which reencryption timeout is specified. If encryption is enabled for a parameter while data is flowing, since its encrypted value won't be available, insertion of that parameter stops.

Note	This feature does not support recovery of flows.

This section describes how to configure the X-Header Insertion feature.

To configure the X-Header Insertion feature:

Creating the X-Header Format

To create an x-header format, use the following configuration:

configure  
   active-charging service ecs_service_name 
      xheader-format xheader_format_name 
      end 

Configuring the X-Header Format

To configure an x-header format, use the following configuration:

configure  
   active-charging service ecs_service_name 
      xheader-format xheader_format_name 
         insert xheader_field_name string-constant xheader_field_value | variable { bearer { 3gpp { apn | charging-characteristics | charging-id | imei | imsi | qos | rat-type | s-mcc-mnc | sgsn-address } | acr | customer-id | ggsn-address | mdn | msisdn-no-cc | radius-string | radius-calling-station-id | session-id | sn-rulebase | subscriber-ip-address | username } [ encrypt ]  [ delete-existing ]  | http { host | url } } 
         end 

This section describes how to configure the X-Header Encryption feature.

Configuring X-Header Encryption

To configure X-Header Encryption, use the following configuration example:

configure  
   active-charging service ecs_service_name 
      rulebase rulebase_name 
         xheader-encryption certificate-name certificate_name 
         xheader-encryption re-encryption period re-encryption_period 
         end 

NOTES:

• This configuration enables X-Header Encryption for all subscribers using the specified rulebase.

• If the certificate is removed, ECS continues using the copy that it has. The copy is set free once the certificate name is removed from the rulebase.

• Changes to x-header format configuration won't trigger re-encryption for existing calls. The changed configuration will however, be applicable for new calls. The changed configuration will also apply at the next reencryption time to those existing calls for which reencryption timeout is specified. If encryption is enabled for a parameter while data is flowing, since its encrypted value won't be available, insertion of that parameter stops.

Configuring Encryption Certificate

To configure the encryption certificate, use the following configuration:

configure  
   certificate name certificate_name pem { { data pem_certificate_data private-key pem [ encrypted ] data pem_pvt_key } | { url url private-key pem { [ encrypted ] data pem_pvt_key | url url } } 
   end 

Enter the following command in the Exec Mode to verify your configuration: