Publikace
Performance Evaluation of Quality of Service Assurance in MPLS Networks
The paper introduces the main features of the mechanism of Multiprotocol Label Switching (MPLS) and evaluates the behaviour of MPLS implementation in current IP networks with respect to Quality of Service support. For this purpose a simulation model was created to examine several aspects of service differentiation in MPLS networks and to evaluate mutual influences of transmission parameters for different traffic classes.
Evaluation of Bandwidth Constraint models for MPLS networks
The paper examines the two basic Bandwidth Constraint models for MPLS networks, called Maximum Allocation Model and Russian Dolls Model, from the point of view of Quality of Service guarantees and introduces the results of performance evaluation of these models in a simulation scenario.
Mutual Cooperation of external application and OPNET Modeler simulation environment
The OPNET Modeler is a simulation environment enables modeling of large-scale networks with in detail defined parameters. This paper is focused on one of the important functions of this software tool which is the ability to interconnect it with a real external system. Thanks to predefined modules and interfaces it is possible to carry out the data exchange between the OPNET Modeler environment and an external system. The client-server model created in the OPNET Modeler is defined in this paper. On the server side the external application was linked over the special interface. This application performed the user data generation and their forwarding into the OPNET Modeler. In the simulation environment received data were put together and sent to the client side where they were displayed and checked.
Analytical Evaluation of IEEE 802.11e QoS Enhancement for Wireless Local Area Networks
The IEEE 802.11e standard introduces a system of Access Categories (AC) and differentiated medium access control mechanisms for wireless local area networks. The preferential or deferral treatment of frames is achieved using configurable Arbitration Inter-Frame Spaces (AIFS) and customizable Contention Window (CW) sizes. In this paper we introduce a general algorithm which calculates the probability of winning the contention by a given AC, based on the values of AIFS lengths and CW sizes.