The total congestion cost, which is the value of wasted time and fuel, is estimated to have cost US urban areas $101 billion in 2010, or $713 per commuter. The largest urban areas, not surprisingly, incur the highest congestion costs (see figure 1).
Cisco Packet Tracer is a powerful network simulator that can be utilized in training for CCNA TM and CCNP TM certification exam by allowing students to create networks with an almost unlimited number of devices and to experience troubleshooting without having to buy real CiscoTM routers or switches.
Firewall DNAT's the packet and runs the packet through all different chains etcetera. Packet leaves the firewall and travels to the $HTTP_IP. Packet reaches the HTTP server, and the HTTP box replies back through the firewall, if that is the box that the routing database has entered as the gateway for $EXT_BOX.