This article presents a simple and inexpensive methodology for predicting the
performance of a client/server application over a wide area network. A
network emulator, placed between the client and server, is used to vary key
network properties, such as latency, bandwidth and packet loss. This method
is not meant to replace extensive network modeling tools such as OPNET or
Load Runner, however, it can provide developers with a simple way to explore
the behavior of applications over a wide area network before deployment. For
example, developers will be able to determine performance over a dial-up line
or low-speed frame relay circuit.
The emulator uses the Linux operating system on a PC with built-in emulation
and queuing utilities. The PC is configured to operate in "brid... (more)