The Internet, private wide area networks, and cloud services represent some of the aspects that connect the user to their application. As users demand faster response and more complex data from their applications, the networks carrying this data are under greater pressure to meet these expectations. To truly test out applications before rolling it out to the users, network emulation must be used. Network emulation is also referred to as wan emulation
Network emulation is used by manufacturers, service providers, and applications developers to verify the robustness of their network product or application. A wan emulator recreates the real world effects seen in the network. Standard features of network emulators include filtering, impairments, modifiers, and routing.
A WAN Emulator or WAN emulation allows to study the real world effects on an application or device in the lab by emulating every wide area network condition.
Filtering allows the wan emulator to separate traffic into different groups to represent different networks. Therefore, a network emulator emulates multiple network scenarios between two emulator ports. Even though end devices are only feet apart and connected to the same server through the emulator, device “A” and device “B” could be viewed to be on different sides of the world by the server.
Why Network emulators
Network emulators use modifiers to serve two purposes: corrupt certain field values and change packet delivery information. A good method to stress an application is to corrupt certain fields in the IP header or the payload to see if the application can overcome it without getting stuck or crashing. Also, modifers of wan emulators can change the packet delivery information such as MAC addresses, IP addresses, or port numbers to either divert the traffic away from the target or steer it to the target.