應用封包時間間隔與時間權杖於優先權限等候機制之研究

Study on Priority-Based Queueing Scheme with Inter-Packet Time and Time Token Measures

本研究提出一個以優先權限為基之等候機制，期望能夠滿足不同優先權限網路應用的差別性服務需求，此一優先權限等候機制將透過各優先權限網路應用流量所屬邏輯佇列空間儲存允入封包，並應用二階段封包允入作業，採取保證允入與差別性允入二種封包允入模式，保證允入採先到先允入 （FCFE） 處理模式，而差別性允入則是以封包抵達時間間隔與時間權杖為基，依封包傳送權限高低進行差別性封包允入處理；另研究所提等候機制將以SRR 機制為基礎，依據網路應用封包權限提供差別性的封包允出處理模式。最後，本研究以NS2 做為模擬載台，將所提等候機制建置於NS2 模擬器，執行數種模擬想定，模擬結果顯示：研究所提等候機制能透過封包抵達時間間隔、時間權杖與SRR機制有效地進行差別性封包允入與允出作業，滿足不同優先權限網路應用流量的差別性服務需求。

This study proposed a priority-based queueing scheme to meet differentiatedQoS requirements of traffic with different priorities over theInternet. Depending on priorities of network applications, the proposedqueueing scheme enqueues arrival packets into logical queueing buffers.It adopted a two-stage packet enqueueing process. One was a promised enqueueingand the other was a differentiated enqueueing. The promisedenqueueing was a FCFI process; and the differentiated enqueueing was basedon inter-packet time, time token and packet’s transmission priority to sup- port a differentiated enqueueing process. Moreover, the proposed queueingscheme based packet transmission priorities of network applications to supporta differentiated packet dequeueing process with SRR. Finally, this studyinstalled NS2 as a simulation platform and implements the proposed queueingscheme in NS2. After executing several simulation scenarios, the simulationresults showed the proposed priority-based queueing scheme dependedon inter-packet time, time token and SRR to support differentiated packet enqueueing/dequeueing process. In addition, they showed that network applicationswith different priorities could receive their correspond- ing QoS.