即時性與非即時性訊息在乙太網路(Ethernet)上之研究

Abstract

新一代的電腦網路應用,亦即多媒體通訊應用已逐漸地萌芽.在今日電腦網 路所選用的環境極大部份為乙太網路 (Ethernet). 乙太網路是一種區域 網路(LAN), 是一種採用數位訊號傳輸方式且具有 CSMA/CD規範的網路.由 於乙太網路最初規化為資料傳輸, 所以無法滿足現今不同多媒體通訊的服 務需求.在本論文中, 以不改變乙太網路架構 (CSMA/CD) 為基礎 ,僅將傳 統乙太網路架構加以修正,取代原有貯列系統 (First-Come-First -Serve) 傳送方式,以傳送及時性訊息為優先的模式整合不同媒體在網路 上之傳輸. 此修正模式,藉著採用 Event-Driven 模擬程式來模擬. 結果 顯示 , 對多媒體通訊在乙太網路上之應用,本方法無論在延遲性 (Delay) 或資料所能傳輸的量 (Throughput) 上,都比傳統的方式有較佳 的效果. New computer network applications, called multimedia plications, are evolving recently.In nowadays,the commonironment on which the multimedia applications are tried to runthe Ethernet. Ethernet is a baseband local area network(LAN),h uses digital signaling and carrier sense multiples/collision detection(CSMA/ CD) scheme. Because of thatet can't satisfy the different multimedia communication requirements such that a new modified CSMA/CD protocol isroposed for an integrated voice/data applications in thissis. Instead of trasmitting the queued packet byt-Come-First-Serve (FCFS) discipline in the conventionalnet model, the packets in queue are sent by real- time packet first in the proposed modified model. The modified modelas been simulated by event-driven simulation program and showsetter performance both in delay and throughput considerationthe conventional Ethernet.