Transcoding proxy placement in en-route web caching

Copyright © 2004 IEEEWith the rapid growth of audio and video applications on the internet, caching media objects in transcoding proxies has become an important research topic in recent years. In this paper, we address the problem of finding the optimal locations for placing fixed number of transcoding proxies among the nodes in a network such that the specified objective is achieved. We present an original model for this problem, which makes transcoding proxy placement decisions on all the en-route nodes along the routing path in a coordinated way. In our model, proxy status information along the routing path of requests is used for optimally determining the locations for placing fixed number of transcoding proxies. We formulate this problem as an optimization problem and the optimal locations are obtained using a low-cost dynamic programming-based algorithm. We implement our algorithm and evaluate our model on different performance metrics through extensive simulation experiments. The implementation results show that our model significantly outperforms the random algorithm which places transcoding proxies among the nodes in a network randomly.Keqiu Li, Hong She

Coordinated en-route transcoding caching for tree networks

©2004 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.As transcoding caching is attracting an increasing amount of attention, it is important and necessary to find methods to distribute multiple versions of the same media object in the Internet. In this paper, we first present a mathematical model for the problem of optimally determining the locations in which to place multiple versions of the same media object in tree networks such that the specified objective is achieved. This problem is formulated as an optimization problem. Second, we propose a low-cost dynamic programming-based solution for solving this problem, by which the optimal locations are obtained. Finally, we evaluate our model on different performance metrics through extensive simulation experiments and compare the results of our model with those of existing models that consider transcoding caching either on a path or at individual nodes only.Keqiu Li, Hong She