Currently computer networks are present in almost all informational environments. Simultaneously with extension of computer domains application is growing a number of users, which want to exchange data or to process common information. The cables constitute the physical support for transmission. The process of designing a network includes, among other activities, determination of locations for placement of network equipment, the identification and measurements of cables routes and network outlets locations, elaboration of network detailed plan. This article describes an interactive application for the laboratory work on discipline ,,Computer Networks", which was developed for the purpose of convenience and simplification of this process.