Advanced policy-based routing (APBR)

Junos OS supports advanced policy-based routing (APBR) to specify the outgoing or egress interface for the traffic based on applications. APBR involves classifying a session based on applications and applying the configured rules to reroute the traffic. In order to classify the applications, a deep packet inspection (DPI) engine is used. The DPI engine inspects the content of a traffic session to identify the application. The result of identification is cached in application system cache (ASC). For subsequent sessions, ASC lookup is done to reroute the packet according to a matching rule. APBR allows you to define the routing behavior based on applications by providing more flexible traffic-handling capabilities that offer granular control for forwarding packets based on application attributes.