An {@link org.apache.http.conn.routing.HttpRoute HttpRoute} is the path along which a request has to be sent to the server. The route starts at a local network address and may pass through one or more proxies before reaching the target. Routes through proxies can be tunnelled, and a layered protocol (TLS/SSL) might be put on top of the tunnel. The {@link org.apache.http.conn.routing.RouteTracker RouteTracker} helps in tracking the steps for establishing a route, while an {@link org.apache.http.conn.routing.HttpRouteDirector HttpRouteDirector} determines the next step to take.

The {@link org.apache.http.conn.routing.HttpRoutePlanner HttpRoutePlanner} is responsible for determining a route to a given target host. Implementations must know about proxies to use, and about exemptions for hosts that should be contacted directly without a proxy.