服務品質保證路由技術及其性能評估

Abstract

隨著寬頻網路時代的到來，各種新的應用隨之興起，一些即時性的資料非常需要服務品質的保證，服務品質保證路由技術的需求於是產生。藉由服務品質保證路由技術，可以為這些需要服務品質保證的資料找到一條符合需求的路徑，除此之外，服務品質保證路由技術還需要考慮每條路徑對網路上其它資料的影響，因此，每當一個新的連線產生時，路徑的決定變成了需要考慮的重點。 除了考慮路由對需要服務品質保證資料的影響外，也需要考慮它對其它不要求服務品質保證資料的影響，因為現在網路上屬於不要求服務品質保證的資料仍占有相當大的比例。因此，在這篇論文中，除了探討路由技術外，我們還提出了另一個虛擬剩餘頻寬的概念，目的就是要讓要求服務品質保證的資料得到頻寬的保證，並且讓不要求服務品質保證的資料也盡量得到較高的傳輸流量，並讓每個連線得到較公平的網路資源。

With the coming of Broadband Internet era, there are more and more new applications. Some real-time applications need guarantees for QoS (Quality of Service), so the demand for QoS routing algorithms comes into existence. QoS routing algorithm can find a path that is satisfied with the requests for the QoS traffic. Besides, the QoS routing algorithms have to consider their effect on the other traffic in the network. Each time when a new connection comes into the network, the selection of its routing path is an important issue. In addition to considering the effect on QoS traffic when we decide the routing path, we also have to consider the effect on best effort traffic. The best effort traffic still occupy a large portion of the Internet traffic. Therefore, in addition to discuss the routing algorithm, we propose another idea of virtual residual bandwidth in this thesis. There are several purposes of our idea. One is to guarantee the QoS traffic to obtain the requested bandwidth. The other is to make the best effort traffic have throughput as high as possible and make each connection earn fair resource.