RACF and CLF AVPs

Frame-IP-Address AVP

The Diameter CLF and RACF interfaces can send a Frame-IP-Address AVP. You can configure the value to appear in either an ascii string (e.g., 192.168.10.1) or an octet string (e.g.,0xC0A80A01) with the framed ip addr encoding parameter.

1637 - Diameter Destination Realm AVP

As of S-C6.2.0, the Destination Realm AVP’s value does not contain the realm of the incoming SIP message. Now, it contains the realm where the Policy Server resides as learned from the Origin-Realm AVP received in a CEA message from the Policy Server.

The Oracle Communications Session Border Controller can be configured with an option, include-gua , to retain the previous behavior of sending an incoming SIP message’s realm to a policy server. This is accomplished by sending the Globally Unique AVP in the AAR message to the policy server, by adding an option parameter to the external policy server configuration.

The following table summarizes the effect of provisioning the external policy server with the Globally Unique AVP option on each Diameter interface, as configured.

Diameter Interface	No include-gua option Configured (default)	Add include-gua option
Rq	AAR sends Globally Unique Address AVP	AAR sends Globally Unique Address AVP
Rx	AAR does not send Globally Unique Address AVP	AAR will contain Globally Unique Address AVP
Gq	AAR does not send Globally Unique Address AVP	AAR will contain Globally Unique Address AVP
E2	AAR sends Globally Unique Address AVP	AAR sends Globally Unique Address AVP

Legacy Destination-Realm AVP Behavior

The Diameter CLF and RACF interfaces can change the format of the payload string in the Destination-Realm AVP for any Diameter message it originates and sends to an external server. The payload field for this AVP can be constructed in any the following formats:

Format	Description
<user>@<realm>	<user>—IP address of the endpoint initiating the call with the Oracle Communications Session Border Controller <realm>—Name of the realm on which the Oracle Communications Session Border Controllerreceived the INVITE from a user
<user>	<user>—IP address of the endpoint initiating the call with the Oracle Communications Session Border Controller
<realm>	<realm>—Name of the realm on which the Oracle Communications Session Border Controller received the INVITE from a user

When either the Diameter CLF or RACF interface sends any message with the Destination-Realm AVP, it determines from the external policy server configuration how to construct the payload string for this AVP.

You can set the format to use in the dest-realm-format parameter in the external policy server configuration. The parameter can be set to any value in the table above and defaults to <user>@<realm>. By treating the format this way, the policy server and the Oracle Communications Session Border Controller can easily communicate this value; if sent to the policy server in any AVP, the policy server can simply return the full value.

Origin-Host AVP

The Diameter CLF and RACF interfaces can change the suffix for Origin-Realm and Origin-Host AVPs that have a payload string constructed as a domain name.

You can set the suffix you want appended to payload strings using the domain-name-suffix parameter in the external policy server configuration. This parameter can be set to any string (default is .com), and the Oracle Communications Session Border Controller automatically adds a dot (.) to the front of this entry if you do not include one. The policy server and the Oracle Communications Session Border Controllercan easily communicate this value; if sent to the policy server in any AVP, the policy server can simply return the full value.

Wildcard Transport Protocol

The Oracle Communications Session Border Controller external bandwidth management solution provides for an Rx interface that supports the Flow-Description AVP (507). Rather than use a numerical value, this Flow-Description AVP uses an IP filter rule with the keyword “ip.” The ip keyword means any transport protocol matches the Flow-Description AVP when issuing AARs to the PCRF. Before it forwards a Gx RAR messages to the softswitch, the PCRF decodes the audio codec into the correct speed and classification. The PCRF passes the Oracle Communications Session Border Controllers Flow-Description AVP to the softswitch untouched. But not all softswitches accommodate the ip keyword, resulting in rejected requests.

Figure 17-2 Interfaces Supporting Diameter Bandwidth Management

Depicts the interfaces used between components of deployment.

When you enable the wildcard-transport-protocol parameter, however, you can essentially format the Flow-Description AVP to suit your network.

For sessions that need to allocate media and have applicable external bandwidth management associations, the Oracle Communications Session Border Controller’s Diameter interface checks for the necessary bandwidth. The Diameter interface, with an Rx or Rq application mode, constructs an AAR with Flow-Description AVP of ip when the wildcard-transport-protocol parameter is enabled. The flow description would look like this:

<Flow-Description-AVP(507) | Avp Flags=128 | AVP Length=72 | Vendor-Id=10415
Data = permit out ip from 168.192.24.20 49500 to 168.192.24.0 8000
<Flow-Description-AVP(507) | Avp Flags=128 | AVP Length=72 | Vendor-Id=10415
Data = permit in ip from 168.192.24.0 8000 to 168.192.24.20 49500

With the wildcard-transport-protocol set to disabled, the Oracle Communications Session Border Controller does not use the ip wildcard keyword. Instead, it uses the specific media stream transport protocol in the Flow-Description AVP—and only falls by to the ip keyword when the transport protocol is unknown. The flow description with this parameter disabled would look like this:

<Flow-Description-AVP(507) | Avp Flags=128 | AVP Length=72 | Vendor-Id=10415
Data = permit out 17 from 168.192.24.20 49500 to 168.192.24.0 8000
<Flow-Description-AVP(507) | Avp Flags=128 | AVP Length=72 | Vendor-Id=10415
Data = permit in 17 from 168.192.24.0 8000 to 168.192.24.20 49500

New Configurations and Upgrading

To comply with 2GPP TS 29.213, wildcard-transport-protocol parameter is disabled by default in new configurations. So if the transport protocol is known, the Oracle Communications Session Border Controller uses it in the Flow-Description AVP.

To maintain default behavior for existing configurations, the Oracle Communications Session Border Controller performs a check at the time of upgrade to set this parameter to enabled. This setting means the Oracle Communications Session Border Controller does use the ip keyword in the Flow-Description AVP.