Mapping Between SRC Software, Junos OS, and PCC Concepts

This section describes the mapping between the SRC software and Junos OS concepts and the policy and charging control (PCC) concepts. During these discussions, refer to Table 10, which describes the mapping between SRC software and Junos OS terminology and the policy and charging control (PCC) function terminology.

Table 10: SRC Software and Junos OS Terminology Versus PCC Terminology

SRC Software and Junos OS Terminology	PCC Terminology
Subscriber session	IP CAN Session
Service with associated policies	PCC Rule
Service activation	Rule-Install
Service deactivation	Rule-Uninstall
Service accounting	Usage-Monitoring
Service templates, defined by SRC	Predefined Rule
Policies, defined by the PCRF	Dynamic Rule

Charging Rule Installation (Service Activation)

A PCRF can activate any number of non-parameterized and parameterized services (predefined PCC rules) in the same CCA or RAR message by providing a Charging-Rule-Install AVP. The Charging-Rule-Install AVP can contain multiple Charging-Rule-Name AVPs, one for each non-parameterized service to be activated. The Charging-Rule-Install AVP can also contain multiple Charging-Rule-Definition AVPs, one for each parameterized service session that is to be activated.

Note: The names appearing in the Charging-Rule-Name AVPs must be unique; the same name must not appear multiple times in the same Gx message.

The SRC 3GPP gateway expects to receive the following AVPs from the PCRF in CCA and RAR messages:

Charging-Rule-Install ::= < AVP Header: 1001 > 
       *[ Charging-Rule-Definition ] 
       *[ Charging-Rule-Name ] 
       *[ Charging-Rule-Base-Name ] 
       *[ AVP ]

Where:

Charging-Rule-Definition ::= < AVP Header: 1003 >
   {Charging-Rule-Name}
   [Juniper-Substitution]

   *[Juniper-Substitution]

Juniper-Substitution::= < AVP Header: 2024>
     {Juniper-Substitution-Name}
     {Juniper-Substitution-Value"}

Table 11 describes these AVPs.

Table 11: AVP Definitions

AVP	Code	Type	VendorID	Description
Charging-Rule-Name	1005	UTF8String	VID_3GPP	To activate a parameterized default service session, specify the serviceName in the format: ruleName@00010001 and specify the ruleName in numeric format.
Juniper-Substitution-Name	2025	UTF8String	VID_JNPR	Name of parameter as defined in the SRC policy definition.
Juniper-Substitution-Value	2026	UTF8String	VID_JNPR	Value to assign to the parameter.

Installing Non-Parameterized Predefined Charging Rules

Non-parameterized predefined charging rules are equivalent to activating an SAE service with no parameters.

The Charging-Rule-Install AVP provides the list of Charging-Rule-Names. The Charging-Rule-Name AVP sent by the PCRF must correspond to the SRC service name.

Note: The Charging-Rule-Base-Name AVP is not supported and is ignored by the SRC 3GPP gateway.

Installing Parameterized Predefined Charging Rules

Parameterized predefined charging rules are equivalent to activating an SAE service with parameters.

The Charging-Rule-Definition AVP must be provided with the list of parameters in a list of Juniper-Substitution-Name AVPs.

For activating a default service session, the Charging-Rule-Name AVP must be set to the SRC service name.
Specify the serviceName in the format ruleName@dynamicfixedPart. For example, “ruleName@00010001” where ruleName is in numeric format and the dynamicFixedPart is a fixed length (size is 8) identifier generated by the PCRF.

Note: Only default sessions are supported.

Example of Charging-Rule Installation

The following example Charging-Rule-Install AVP, sent by the PCRF, activates the services “foo1” and “foo2” with no parameters. It also activates the service “123” with two parameters and the service “456” with one parameter.

AVP: Charging-Rule-Install(1001)
        AVP: Charging-Rule-Name(1005) val=foo1  <- Activate service foo1
        AVP: Charging-Rule-Name(1005) val=foo2  <- Activate service foo2
    AVP: Charging-Rule-Definition(1003) vnd=VID_3GPP  <- 3GPP AVP for activating parameterized service “123” with 2 parameters
            AVP: Charging-Rule-Name (1005) vnd=3GPP val=123@00010000
      AVP: Juniper-Substitution (2024) vnd=JNPR
      	          AVP: Juniper-Substitution–Name(2025) vnd=JNPR val=rate
          AVP: Juniper-Substitution–Value(2026) vnd=JNPR val=5
      	      AVP: Juniper-Substitution (2024) vnd=JNPR
          AVP: Juniper-Substitution–Name(2025) vnd=JNPR val=color
      	          AVP: Juniper-Substitution–Value(2026) vnd=JNPR val=red
AVP: Charging-Rule-Definition(1003) vnd=VID_3GPP  <- 3GPP AVP for activating parameterized service “456” with 1 parameter
            AVP: Charging-Rule-Name (1005) vnd=3GPP val=456@00010001
      AVP: Juniper-Substitution (2024) vnd=JNPR
          AVP: Juniper-Substitution–Name(2025) vnd=JNPR val=rate
          AVP: Juniper-Substitution–Value(2026) vnd=JNPR val=10

In this example, foo1, foo2, 123 (rate, color), and “456” (rate) are configured services in the SRC software.

Charging Rule Removal (Service Deactivation)

A PCRF can deactivate any number of non-parameterized and parameterized services (predefined PCC rules) in the same CCA or RAR message by providing a Charging-Rule-Remove AVP. The Charging-Rule-Remove AVP can contain multiple Charging-Rule-Name AVPs, one for each non-parameterized or parameterized service to be deactivated.

The following AVPs are expected by the SRC (PCEF) from the PCRF in CCA and RAR messages:

Charging-Rule-Remove ::= < AVP Header: 1002 > 
       *[ Charging-Rule-Definition ] 
       *[ Charging-Rule-Name ] 
       *[ Charging-Rule-Base-Name ] 
       *[ AVP ]

For non-parameterized charging rules, the Charging-Rule-Name AVP must correspond to the one provided in the Charging-Rule-Install AVP.
For parameterized charging rules, the Charging-Rule-Name AVP must correspond to the one provided in the Charging-Rule-Definition AVP. If this format is not specified, the value in the Charging-Rule-Name AVP is treated as the serviceName.

Note: Charging-Rule-Base-Name AVP is not supported and is ignored by the SRC 3GPP gateway.

Example of Charging-Rule Removal

The following example Charging-Rule-Removal AVP, sent by the PCRF, deactivates the SRC services called “foo1”, “foo2”, and “123”.

AVP: Charging-Rule-Remove(1002)
             AVP: Charging-Rule-Name(1005) val=foo1 <- Deactivate service foo1
             AVP: Charging-Rule-Name(1005) val=foo2 <- Deactivate service foo2
             AVP: Charging-Rule-Name(1005) val=123@00010001  <- Deactivate service 123

Charging Rule Report

The SRC 3GPP gateway can send charging rule reports for any number of non-parameterized and parameterized services in the same Credit Control Update (CCR-U) request or RAA message. This is achieved by providing a Charging-Rule-Report AVP for each failed service. The Charging-Rule-Report AVP contains a single Charging-Rule-Name AVP (for a non-parameterized or a parameterized service).

Charging-Rule-Report ::= < AVP Header: 1018 > 
       *[ Charging-Rule-Name ] 
       *[ Charging-Rule-Base-Name ] 
				 [ PCC-Rule-Status ]
			    [ Rule-Failure-Code ]
				*[ AVP ]

For non-parameterized charging rules, the Charging-Rule-Name AVP corresponds to the one provided in the Charging-Rule-Install AVP.
For parameterized charging rules, the Charging-Rule-Name AVP must correspond to the one provided in the Charging-Rule-Definition AVP. If this format is not specified, the value in the Charging-Rule-Name AVP is treated as the serviceName.

Note: The Charging-Rule-Base-Name AVP is not supported and is never sent by the SRC 3GPP gateway.

Service Accounting

You can perform service accounting for one or more PCC rules.

When a PCRF requests service accounting, it needs to include an Event-Trigger AVP, set to “USAGE_REPORT”. This setting must be set in either the RAR message (if the PRCF initiates the PCC rule changes), or the CCA message (if the user equipment initiates the rule changes).

The PCRF may also provide usage threshold levels to the SRC 3GPP gateway at session establishment or modification time (CCA or RAR message). This is done, by setting those thresholds in the grouped Grant-Service-Unit AVP per Monitoring-Key in the Usage-Monitoring-Information AVP. The threshold level may be defined for:

Total volume only (CC-Total-Octets AVP within Granted-Service-Unit hold threshold for total volume)
Uplink volume only (CC-Input-Octets AVP within Granted-Service-Unit hold threshold for uplink volume)
Downlink volume only (CC-Output-Octets AVP within Granted-Service-Unit hold threshold for downlink volume)

The Monitoring-Key AVP format is similar to the format of the Charging-Rule-Removal and Charging-Rule-Report AVPs:

For non-parameterized charging rules, the Monitoring-Key AVP must be set to the Charging-Rule-Name AVP provided in the Charging-Rule-Install AVP.
For parameterized charging rules, the Monitoring-Key AVP must be set to the Charging-Rule-Name AVP provided in the Charging-Rule-Install AVP (from the Charging-Rule-Definition AVP).

The SRC 3GPP gateway does not support SESSION_LEVEL monitoring. This means that the only supported value for the Usage-Monitoring-Level AVP is PCC_RULE_LEVEL.

The SRC 3GPP gateway sends accounting updates when it receives interim updates from the SAE for the service session. This is done by setting the usage counters in the Used-Service-Unit AVP within the Usage-Monitoring-Information AVP. Like the Granted-Service-Unit AVP (for setting the threshold), the Used-Service-Unit AVP is a grouped AVP and the SRC 3GPP gateway uses the CC-Total-Octet, CC-Input-Octets, and CC-Output-Octets AVP within the Used-Service-Unit AVP to report the usage to the PCRF. The SRC 3GPP gateway sends this only in CCR messages (not in RAA messages). The reporting is done when any of the following conditions are met:

When a usage threshold is reached.
- The SRC 3GPP gateway stores the threshold information (provided by the PCRF) in the SAE session during service activation or modification.
- After the SRC 3GPP gateway receives an interim update for a service session, it checks whether any of the thresholds were reached.
- If a threshold is reached, the SRC 3GPP gateway generates a CCR-U to the PCRF and includes the accumulated usage volume in the Usage-Monitoring-Information AVP.
- The Event-Trigger AVP is set to USAGE_REPORT.
When the service is deactivated (the PCC rule, for which service accounting is enabled, is removed).
- This is done after the SRC 3GPP gateway deactivates a given service (in response to an RAR or CCA message).
- The SRC 3GPP gateway generates a CCR-U to the PCRF and includes the accumulated usage volume in the Usage-Monitoring-Information AVP.
- The Event-Trigger AVP is set to USAGE_REPORT.
When service accounting is explicitly disabled by the PCRF for a specific PCC rule.
- This is done if the SRC 3GPP gateway receives a CCA or RAR message with the Usage-Monitoring-Support AVP set to USAGE_MONITORING_DISABLED for a specific Monitoring-Key within the Usage-Monitoring-Information AVP.
- The SRC 3GPP gateway generates a CCR-U to the PCRF and includes the accumulated usage volume in the Usage-Monitoring-Information AVP.
- The Event-Trigger AVP is set to USAGE_REPORT.
When an IP-CAN session is terminated (either by the PCRF through an RAR message, or initiated by the user equipment).
- For each service (the PCC rule, for which service accounting is enabled):
  - The SRC 3GPP gateway generates a CCR-U to the PCRF and includes the accumulated usage volume in the Usage-Monitoring-Information AVP for the specific service.
  - The Event-Trigger AVP is set to USAGE_REPORT.
- The SRC 3GPP gateway also generates a termination request (CCR-T) message to the PCRF but does not include any usage report in it.
When requested by the PCRF.
- This is done if the SRC 3GPP gateway receives an RAR message with the Usage-Monitoring-Report AVP set to USAGE_MONITORING_REPORT-REQUIRED within the Usage-Monitoring-Information AVP.
- The SRC 3GPP gateway generates a CCR-U to the PCRF for each requested Monitoring-Key AVP and includes the accumulated usage volume in the Usage-Monitoring-Information AVP.
- The Event-Trigger AVP is set to USAGE_REPORT