In this paper, we propose a new QoS mapping mechanism for video transport in a network using the DiffServ architecture. Video packets mapping is based on the QoS index, which represents the preference of each video flow in terms of loss and delay. Then, in a specified video application, the QoS mapping will be given by prioritizing certain packets according to its importance in MPEG video streams and the desired end-to-end quality. In order to verify the efficiency of this mechanism, the end-to-end system performance was evaluated by means of modeling and simulation of MPEG-4 video transmission over a DiffServ domain. The results showed that the proposed QoS mapping mechanism can take advantage of the DiffServ architecture, making possible enhanced end-to-end video quality according to the user, and applications needs.
The Label Switching technology was developed in order to provide a high speed and large packet processing capabilities in Internet networks using a cut-through technique. Research effort has concentrated on the issue of number of labels used and its minimization. There are mainly two label mapping policies. One is the data-driven label mapping policy and the other is the control-driven label mapping policy. In this paper, a comparison between both conventional label mapping policies is shown. It is also evaluated the required number of labels under each of these two label mapping policies and the cut-through ratio of each one. The evaluation shows that the data-driven and the control-driven label mapping policies require a large number of labels. In order to reduce the number of labels required and increase the cut-through ratio, it is proposed a label mapping policy that is a combination of the two label mappings above. This is a control-driven label mapping that has the soft-state characteristic of the data-driven one. The evaluation shows that the proposed label mapping policy requires less labels than the others conventional label mapping policies and increases the cut-through ratio to the maximum allowed while offering the advantages of being a control-driven label mapping.