Testing of QoS support in experimental data network

This work deals with the qualitative requirements on services in IP networks based on technology Ethernet. We describe basic methods for imposing quality control mechanisms on services within networks. We elaborate on the ways, in which packets can be handled, overload controlled and transfer speed in network elements limited. Attention is given also to the Network Layer and Link Layer. Based on concrete specifications of network devices in UTKO laboratory an experimental network was designed and constructed. Network consisting of routers and switches linked several servers with client stations. Various types of data transfers (VoIP, HTTP, FTP, video) were generated. Several techniques for handling packets with different priorities were verified and compared. We observed that, in situations when connections are under full load, implementation of QoS support in the network becomes very important. This observation was confirmed by measurements. We also measured the parameters of the system during simulations of various situations, such as overload of a connection due to unsolicited operations or failure of a connection between routers. In order to guarantee the quality of services it is necessary to create a domain, in which rules are consistently observed in all network elements