> - Downloads
> - COPS Connection Between JUNOSe Routers and the SAE
> - Related Topics
> - Storing Subscriber and Service Session Data
> - Adding JUNOSe Routers and Virtual Routers with the CLI
> - Developing Router Initialization Scripts for JUNOSe Routers, JUNOS Routing Platforms, and Network Devices
> - How SNMP Obtains Information from Routers for the SRC Software
> - Configuring the SAE to Manage JUNOSe Routers with the CLI
> - Starting the SRC Client on a JUNOSe Router
> - Monitoring Interactions Between the SAE and the JUNOSe Router

> ## COPS Connection Between JUNOSe Routers and the SAE

> Configuring the SRC client on a JUNOSe router opens a Common Open Policy Service (COPS) protocol layer connection to the SAE. When the SRC client software establishes a TCP/IP connection to the SAE, the SAE starts to manage the JUNOSe router. Subsequently, the SRC client sends configuration changes made on the JUNOSe router to the SAE, and the SAE updates SRC configurations for services and policies accordingly.

> The SAE supports two versions of COPS:

> - COPS usage for policy provisioning (COPS-PR)
> - COPS External Data Representation Standard (COPS-XDR)

> 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.

> ## Highly Available Connections to JUNOSe Routers

> JUNOSe routers maintain state information, a feature that allows an active, managing SAE to reconnect to a JUNOSe router without a performing a data resynchronization in the following instances:

> - The network connection between the SAE and the JUNOSe router is disrupted, and the router reconnects to the SAE
> - For JUNOSe routers with high availability configured, when the secondary SRP takes control from a failed SRP it can reconnect to the SAE

>   To maintain highly available connections to JUNOSe routers, configure an SAE community and the session store by configuring SAE identifiers for in the configuration for the shared network device virtual router. In the configuration, an exclamation point identifies standby SAEs.

> #### Published: 2009-09-15

> Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice.