The real-time network simulation requires dealing with miscellaneous technical problems to achieve a correct and timely execution. The ignorance of those issues can render a valid model useless, because its implementation would produce erroneous results. This paper identifies and discusses the problems specific for a Linux operating system on the x86 architecture. A problem of accurate event scheduling in a simulation process without disturbing other processes is the most important and is considered in detail. Several solutions to this problem are evaluated by measurements. The results show that no single solution fits all criteria, but the most appropriate method can be selected according to goals of a simulation study.