佇列空間配置植基於時間權杖之差別性服務等候機制研究

本研究提出一個差別性服務等候機制，此等候機制將佇列空間配置區分為二大區塊：專屬佇列空間與共享配置空間。各優先權限流量有其專屬靜態佇列空間，採先到先允入模式，而共享配置空間則應用時間權杖措施，針對不同優先權限的流量進行動態且差別性的佇列空間配置，以達到差別性封包允入的效能；此外，研究所提差別性服務等候機制將以SRR（Shaped Round Robin）封包允出作業為基，搭配各流量的優先權限及可轉讓封包允出權杖機制，進行封包允出作業，使得封包允出作業亦能對不同優先權限的流量提供差別性的封包允出效能。最後，本研究透過C++將所提機制建置於NS2模擬器，並利用TCL（Tool Command Language）撰寫模擬想定程式，執行數種模擬想定，模擬結果顯示：研究所提差別性服務等候機制能透過時間權杖措施有效地動態配置佇列空間，滿足不同優先權限網路應用的差別性服務需求，且其能以相對較低的運作成本，獲得與IETF DiffServ機制十分接近的運作效能。

關鍵字

時間權杖；佇列空間配置；差別性服務等候機制

並列摘要

This study proposes a differentiated service queueing scheme. The proposed scheme divides a queueing buffer into two blocks, one is a dedicated buffer and the other is a shared allotment buffer. Traffic with different priority would receive its dedicated queueing buffer in a fixed size to enqueue its packets with a first come first enqueueing scheme. The shared allotment buffer would base on a time token measure to allot packet enqueueing space dynamically for traffic with different priorities in a differentiated way. And, the proposed scheme bases on SRR (Shaped Round Robin), priorities of traffic and a transferable packet dequeueing token measure to support differentiated packet dequeueing performance for traffic. Finally, this study implements the proposed scheme with C++ in a NS2 simulator and codes several simulation scenarios with TCL (Tool Command Language). The simulation results show the proposed scheme can depend on the time token measure to allot a dynamic queueing buffer efficiently and meet transmission requirements of traffic with different priorities. Moreover, the proposed scheme requires a relative low implementation cost, compares with the IETF DiffServ scheme, and its performance is very close to the IETF DiffServ scheme.

並列關鍵字

time token ； queueing buffer allocation ； differentiated service queueing scheme

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