Direct Cloud Access feature has the following components:
Network-Based Application Recognition (NBAR) is a classification engine that recognizes and classifies a wide variety of protocols
and applications. NBAR uses several classification information metadata such as application name, ID, traffic class, business
relevance, and so on.
For Direct Cloud Access feature, when NBAR recognizes the DNS traffic as belonging to cloud application, it attaches the traffic
information to DNS packet so that the Umbrella Connector feature can extract and use the information.
The Umbrella Connector is a component on ISR 4000 series routers that intercepts DNS traffic and redirects it to Umbrella cloud for security inspection and policy application.
If an Umbrella connector is configured to allow local breakout for cloud applications, it redirects DNS traffic from selected
cloud applications. To configure an Umbrella Connector, intercept DNS packet and look for NBAR classification result attached
to the packet. If a match is found, the packet is sent to the Umbrella cloud else the packet is forwarded to the enterprise
Performance Routing (PfR)
Performance Routing (PfR) component delivers intelligent path control for application-aware routing across the WAN. Once a
DNS response is received, the data traffic (HTTP, HTTPS etc.) originating from the cloud application is provided direct internet
access (local break-out) or is hauled back to the headquarter for further security inspection by the PfR component.