Connections to Managed Devices
This topic describes the connections between the SAE and Juniper Networks routers and CMTS devices.
COPS Connection Between JunosE Routers and the SAE
The SAE and JunosE routers communicate using the Common Open Policy Service (COPS) protocol. The SAE supports two versions of COPS:
COPS usage for policy provisioning (COPS-PR)
COPS External Data Representation Standard (XDR) mode
The version of COPS that you use depends on the version of COPS that your JunosE router supports. When you set up your JunosE router to work with the SAE, you enable either COPS-PR mode or COPS XDR mode. There are no configuration differences on the SAE between COPS-PR and COPS XDR.
The following SRC features require the use of COPS-PR:
Policy sharing on JunosE routers
Multiple classify traffic conditions in policy lists
Beep Connection Between Devices Running Junos OS and the SAE
The SAE interacts with a Junos OS process, referred to as the SRC software process, on a device running Junos OS. The SAE and the SRC software process communicate using the Blocks Extensible Exchange Protocol (BEEP).
When a device running Junos OS that the SAE manages goes online, it initiates a BEEP session for the SAE. The SAE gets configuration information from the router, and then it builds and installs the policies that control the router’s behavior. If the policies are subsequently modified in the directory, the SAE builds a new configuration and reconfigures the interface on the device running Junos OS.
The SAE manages interfaces on devices running Junos OS only when the interfaces are configured in the global configuration and the router sends added, changed, or deleted notifications to the SAE. Router administrators should not manually change the configuration of interfaces that the SAE is managing. If you manually change a configuration, you must remove the SAE from the system.
When there are configuration changes on the router, the router sends a notification to the SAE through the BEEP connection. The notification does not include the content of the configuration changes. When the SAE receives the notification, it uses its Junos XML management protocol client to get the changed configuration from the router.
Interfaces that have been deleted from the router along with their associated objects (sessions, policies) remain on the router until state synchronization occurs.
COPS Connection Between CMTS Devices and the SAE
The SAE uses the COPS protocol as specified in the PacketCable Multimedia Specification PKT-SP-MM-I03-051221 to manage PacketCable Multimedia Specification (PCMM)-compliant CMTS devices in a cable network environment. The SAE connects to the CMTS device by using a COPS over Transmission Control Protocol (TCP) connection.
In cable environments, the SAE manages the connection to the CMTS device. The CMTS device does not provide address requests or notify the SAE of new subscribers, subscriber IP addresses, or any other attributes. IP address detection and all other subscriber attributes are collected outside of the COPS connection to the CMTS device. The SAE uses COPS only to push policies to the CMTS device and to learn about the CMTS status and usage data.
Because the CMTS device does not have the concept of interfaces, the SRC module uses pseudointerfaces to model CMTS subscriber connections similar to subscriber connections for devices running Junos OS and JunosE routers.
Diameter Connection Between Junos OS Routers and the SAE
The Diameter base protocol provides basic services to several applications (also called functions) each running in a different Diameter instance. Each individual application provides the extended authentication, authorization, and accounting (AAA) functionality. The supported applications that use the Diameter protocol are Juniper Networks Session Resource Control (JSRC) and Gx (Services Control Gateway).
The SRC software uses the Diameter protocol for communication between the local SRC peer on a Juniper Networks routing platform, such as the Juniper Networks MX Series Ethernet Services Router, and the SAE. The details of Diameter application and the application ID are:
JSRC—A Juniper Networks Diameter application registered with the Internet Assigned Numbers Authority (IANA) as Juniper Policy-Control-JSRC, with an ID of 16777244. The JSRC application communicates with the SAE (remote SRC peer).
Gx-SCG—An application that extends the 3GPP Gx interface and communicates with the SRC software acting as a PCRF for this interface. The 3GPP Gx is registered with the IANA. The application ID of the 3GPP Gx is 16777238.