Messages Used by Diameter Applications

 

Junos OS supports the following Diameter applications:

  • JSRC—A Juniper Networks Diameter application registered with the IANA (http://www.iana.org) as Juniper Policy-Control-JSRC, with an ID of 16777244. It communicates with the SAE (remote SRC peer).

  • PTSP—A Juniper Networks Diameter application registered with the IANA (http://www.iana.org) as Juniper JGx, with an ID of 16777273. It communicates with the SAE (remote SRC peer). Starting in Junos OS Release 13.1R1, the packet-triggered subscribers and policy control (PTSP) feature is no longer supported.

  • Gx-Plus—An application that extends the 3GPP Gx interface for wireline use cases. 3GPP Gx is registered with the IANA (http://www.iana.org). It communicates with a PCRF.

    If data for a particular AVP included in a message is not available to the router, Gx-Plus simply omits the AVP from the message it sends to the PCRF. If the PCRF determines it has insufficient information to make a determination, it may deny the request. The Diameter answer messages include the Result-Code AVP (AVP 268); the values of this AVP convey success, failure, or errors to the requestor.

  • NASREQ—A Diameter-based authentication, authorization, and accounting protocol defined in RFC 7155. Junos OS supports authentication and authorization only.

Juniper Networks has also registered the Juniper-Session-Recovery application (16777296) and two new command codes (8388628 for Juniper-Session-Events and 8388629 for Juniper-Session-Discovery) with the IANA (http://www.iana.org).

Table 1 describes Diameter messages the applications use.

Table 1: Diameter Messages and Diameter Applications

Diameter Message

Code

Application

Description

AA-Request (AAR)

265

JSRC, NASREQ, PTSP

Request from the application to the SAE at new subscriber login or during SAE-application synchronization. The request can be one of three types: address-authorization, provisioning-request, or synchronization.

AA-Answer (AAA)

265

JSRC, NASREQ, PTSP

Response from the SAE to the application’s AA-Request message.

Abort-Session-Request (ASR)

274

JSRC, NASREQ, PTSP

Request from the SAE to the application to log out a provisioned subscriber.

Abort-Session-Answer (ASA)

274

JSRC, NASREQ, PTSP

Response from the application to the SAE’s ASR message. If the application sends the logout request to AAA, the ASA message includes a success notification (ACK). If the logout failed, the ASA message includes a failure notification (NAK).

Accounting-Request (ACR)

271

JSRC, PTSP

Request from the SAE to the application or from the application to the SAE for statistics.

Accounting-Answer (ACA)

271

JSRC, PTSP

Response to the ACR message to provide statistics for each installed policy (service).

Capability Exchange Request (CER)

257

Gx-Plus

Request from one peer to another when the peers establish a transport connection; initiates the capability negotiation. The CER announces the peer’s identity and capabilities, such as applications and security mechanisms supported.

Capability Exchange Answer (CEA)

257

Gx-Plus

Response to the CER message to announce this peer’s capabilities. If this peer has no capabilities in common with the peer that sent the CER, then it must set the Result-Code AVP to DIAMETER_NO_COMMON_APPLICATION and should drop the connection. Otherwise, the CEA details establish common capabilities between the peers and enable them to further establish communication.

Credit-Control-Request (CCR)

272

Gx-Plus

Request from Gx-Plus to the PCRF at subscriber login, logout, or update.

An initial request (CCR-I) is sent when a subscriber logs in and AAA is requested to activate the subscriber’s session. Gx-Plus retries the CCR-I message if a CCA-I message is not received from the PCRF within 10 seconds. The CCR-I message is retried up to 3 times.

The CCR-I message includes the Diameter AVP Subscription-Id attribute (443) with the Subscription-Id-Type Diameter AVP sub-attribute (450) set to 4 (END_USER_PRIVATE) and the Subscription-Id-Data Diameter AVP sub-attribute (444) set to reserved.

If no CCA-I is received after the 4 CCR-I messages have been sent—the first message plus 3 retries—then Gx-Plus starts sending CCR-N messages. CCR-N messages are retried forever until a success or failure response is received from the PCRF. CCR-N messages include the Juniper-Provisioning-Source AVP (AVP code 2101) set to local to notify the PCRF that the router has the authority to make a local decision regarding subscriber service activation.

An update request (CCR-U) message is sent when a usage threshold is reached. The CCR-U reports the actual usage for all statistics. The PCRF may return a CCA-U message that includes new monitoring thresholds, service activations, service deactivations.

If the PCRF times out on the CCR-U report, the router sets the threshold default to 10 minutes. When the change in threshold values is less than the minimum, the values are adjusted to the minimums. For example, the minimum increase for duration is 10 minutes.

A CCR-U is also sent to report the status of service activation or deactivation. When a monitored service is deactivated separate from a subscriber logout, the CCR-U indicates that the service is no longer active and includes the service’s usage data.

A CCR-U is sent to the PCRF after the router sends an RAA message in response to an RAR message that requests service activations or deactivations.

A termination request (CCR-T) is sent at subscriber logout to inform the PCRF that a provisioned subscriber session is being terminated. CCR-T messages are retried forever until a success response is received from the PCRF.

When a monitored service is deactivated as part of the subscriber logout, the CCR-T message includes monitored usage data for the service, such as bytes used.

Credit-Control-Answer (CCA)

272

Gx-Plus

Reply from the PCRF to a CCR message.

In response to a CCR-I, the PCRF returns a CCA-I message that indicates success (DIAMETER_SUCCESS) or failure (DIAMETER AUTHORIZATION REJECTED) depending on whether the subscriber has sufficient credit for the requested services. All other responses are ignored and the CCR-I is retried.

In response to a CCR-T, the PCRF returns a CCA-T message that indicates a successful termination with a value of 2001 (DIAMETER SUCCESS) in the Result-Code AVP. All other responses are ignored and the CCR-T is retried.

A CCA-N is a response to a CCR-N.

Juniper-Session-Discovery-Request (JSDR)

8388629

Gx-Plus

Discovery request from the PCRF to Gx-Plus to discover subscriber sessions on the router.

Juniper-Session-Discovery-Answer (JSDA)

8388629

Gx-Plus

Reply from router to a JSDR message; describes session information. The Result-Code AVP includes one of the following values, or an error value:

  • 2001—DIAMETER_SUCCESS; the end of the database was reached, meaning all information has been sent.

  • 2002—DIAMETER_LIMITED_SUCCESS; some of the session information was sent, but more remains to be sent.

Juniper-Session-Event-Request (JSER)

8388628

Gx-Plus

Request from router to PCRF regarding events that take place on the router. Notifies the PCRF of certain events on the router by including the Juniper-Event-Type AVP (AVP code 2103). Events reported include cold or warm boots, explicit discovery requests, substantial configuration changes, non-response or error response from PCRF, and exhaustion of fault-tolerant resources.

Juniper-Session-Event-Answer (JSEA)

8388628

Gx-Plus

Reply from PCRF to a JSER message.

Push-Profile-Request (PPR)

288

JSRC, PTSP

Request from the SAE to the router to activate or deactivate services for a subscriber.

Push-Profile-Answer (PPA)

288

JSRC, PTSP

Response from the router to the SAE’s PPR message. Includes success or failure notification for each of the service activation or deactivation commands in the request.

Re-Auth-Request (RAR)

258

Gx-Plus

Audit request from the PCRF to router to determine whether a specific subscriber is still present.

The router updates the monitoring key and threshold values when they are received in the RAR.

Re-Auth-Answer (RAA)

258

Gx-Plus

Reply from router to a RAR message; indicates whether the subscriber is active. The Result-Code AVP includes one of the following values:

  • 2001—DIAMETER_SUCCESS; subscriber entry was found.

  • 5002—DIAMETER_UNKNOWN_SESSION_ID; subscriber entry was not found.

  • 3002—DIAMETER_UNABLE_TO_DELIVER; Gx-Plus is not configured.

Session-Resource-Query (SRQ)

277

JSRC, PTSP

Request from the router to the SAE or from the SAE to the router to initiate synchronization between router and the SAE.

Session-Resource-Reply (SRR)

277

JSRC, PTSP

Response to the SRQ message to begin synchronization.

Session-Termination-Request (STR)

275

JSRC, NASREQ, PTSP

Notification from the router to the SAE that a provisioned subscriber has logged out.

Session-Termination-Answer (STA)

275

JSRC, NASREQ, PTSP

Response from the SAE to the router’s STR message. Includes success or failure notification.

Release History Table
Release
Description
Starting in Junos OS Release 13.1R1, the packet-triggered subscribers and policy control (PTSP) feature is no longer supported.