Publikace
Advanced Modelling of DiffServ Technology
The Differentiated Services are currently one of the most used mechanisms for the quality of service assurance in IP networks. The basic principle of this network architecture is to separate the network traffic into several classes with the specific priority. This paper is focused on the advanced modelling of this technology in the simulation environment OPNET Modeler. Basic DiffServ parameters such as the Per Hop Behavior index, queuing mechanisms and queue management algorithms are simulated and analyzed. The simulation results and the final evaluation are presented at the end of this paper.
Time analysis of Route Optimization in MIPv6
The Mobile IPv6 protocol allows mobile nodes in IPv6 networks to roam among subnets with various prefixes without the need to change its network address. This allows keeping the running TCP connections active even if the mobile node moves from subnet to subnet and keeps the mobile node reachable by its permanent home address all the time. The Mobile IPv6 protocol provides two ways of delivering data between the mobile node and its peer - bidirectional tunneling or route optimization. In bidirectional tunneling the data is tunneled through a central node in mobile node's home network - the home agent, whereas the other method routes the data directly between the two communicating nodes. The method of route optimization rapidly reduces the end-to-end delay, but requires implementation of Mobile IPv6 also at the mobile node's per. This article provides an analytical method for evaluating these two methods and investigates their effic... Čtěte více
DiffServ Extension Allowing User Applications to Effect QoS Control
The technology of Differentiated Services (DiffServ) is currently one of the most used QoS technologies. The initial place where the QoS control mechanisms of this technology are applied is the edge router of the DiffServ domain. Right this property is one of the biggest disadvantages of DiffServ because it does not support the direct interaction with the user application that can define its QoS requirements most precisely. This paper deals with the proposal of a new QoS control system where the user application is able to cooperate with the edge node of the DiffServ domain and can affect the allocation of network resources. As a communication protocol between the user application and the edge node the well-known SNMP (Simple Network Management Protocol) has been chosen. On the basis of the theoretical proposal the basic simulation model was created in the Opnet Modeler simulating environment. This model is composed from a special... Čtěte více