Designing WANem : A Wide Area Network emulator tool

Software developers are never exposed to production networks which is mostly Wide Area Network (WAN) during the development and unit test cycle. This leads to poor performing applications in production. Often the reason for such poor performance is attributed to the network. Hence it is important for the developers to know the behavior of their applications on various types of networks users will access the application from. However, access to such networks is restricted to a developer who tests his application over a local area network. A local area network (LAN) often has more than the required bandwidth required by an application. Hence a device, which will emulate various network behaviors is required, something which will help developers to better understand the behavior of their application on various networks. In response to this need WANem is designed and developed which can emulate real WAN networks in a development or test environment inside a LAN. In this paper we will discuss the architecture of WANem and show how it affects application performance.