# Application routing

Application routing allows you to apply different NAT rules to traffic, select which VPN traffic uses, and redirect traffic to different proxy servers depending on the network applications detected in the traffic.

Application routing provides the following benefits:

- Many network applications are offered from data centers around the world. Traffic related to specific network applications can be routed to the data center that is geographically closest to the source of the traffic.
- Application routing allows you to optimize the use of limited bandwidth.

Application detection works best on protocols where the client initiates communication. Protocols in which this happens are typically HTTP and HTTPS. To ensure that a Network Application element can be used for matching in application routing, only use elements that have the Application Routing tag. The tag might be added to additional Network Application elements in dynamic update packages.

Some examples of use cases for application routing include the following:

- You can route traffic from specific network applications through the local Internet connection, and route other business traffic to a data center using another connection, such as MPLS.
- You can exclude specific network applications from being redirected to proxies.
- You can direct some network applications to one proxy, and direct the rest of the web traffic to another proxy.
- You can direct all traffic related to a specific network application to one ISP connection, and reserve the other ISP connection for more important traffic. For example, you could direct YouTube traffic to a low-cost ISP connection, and direct business-critical traffic to a faster, but more expensive ISP connection.