Why do we need QoS?
In a typical IP network, the LAN operates at higher speeds (in the Gigabits range), while WAN interfaces run at slower speeds (in the Megabits range).
In a typical IP network, the LAN operates at higher speeds (in the Gigabits range), while WAN interfaces run at slower speeds (in the Megabits range).
A device, such as a router or firewall, can change the IP address information in the packets' headers while packets pass through. This network function is called Network Address Translation (NAT) and is shown in the diagram below.