差異式服務網路之效能分析

Abstract

差異式服務網路是由網際網路工程特別小組所提出之一種屬於服務級基礎型之之保證服務品質之機制。與資料流基礎型機制之不同之處，便是它減去了許多在路由器上儲存資料流資訊的多餘負擔。它在邊際路由器將流量分類後，將具有同一服務品質特質的流量形成聚集的形式，方便核心路由器處理。因為路由器只需對具有相同服務品質特性之數種服務等級處理而不需對每個資料流做處理，便可使得負載降低，並且簡化路由器之設計。本文針對差異式服務之特性，設計了三種相關的可滿足差異式服務之緩衝區機制，並利用模擬的方式，在多服務網路的假設情況下，針對封包的延遲性、資料流的傳輸率及頻寬的分配情況，做了效能分析與評估，企圖瞭解在差異式服務網路架構之下，設計緩衝區機制時所應注意之關鍵因素。

Differentiated service is one of QoS mechanisms proposed by IETF. It is designed for reducing overheads on core routers which the originally flow-based QoS mechanism made. The basic idea is to classify the traffic flows on the boundary routers to aggregate into different service levels aggregations. The core routers will benefit by processing per-class states, not any more per-flow states.This thesis studied three buffer management mechanisms related to differentiated services. And trying to analyze and evaluate the packet latencies, flow throughputs and bandwidth allocations under multi-services network environment with simulation methods. We tried to find out the key factors while designing and implementing the differentiated services networks.