'N' client simulation using user mode Linux

User mode linux (UML) is a open source software that allows to run Linux in a "virtual machine" on top of a physical Linux box. UML allows one to run Linux kernels as user mode processes under a host Linux kernel, giving a simple way to run several independent virtual machines on a single piece of physical hardware. So, with the help of UML, we can simulate large no. of computers (PCs). In this paper we give a methodology to simulate large no. of PCs using UML. These PCs are actually virtual machines running on top of a host. We studied maximum no. of PCs that can be simulated on a host with given RAM. We configure various functions on these PCs such as access to the internet, executing commands on these PCs simultaneously. This simulation is useful in many scenarios especially for experimentation purposes. One application of software will be in testing MPP, a product developed at HSR, Switzerland. It enables users to buy access to the internet at Hotspots. But right now, there is a problem when no. of clients trying to connect simultaneously to a server, exceed a given limit. So, a software to simulate this environment has to be designed to avoid use of large no. of physical computers which is expensive and infeasible.