在軟體定義網路上設計並實作以來源為基礎的鏈結負載平衡多播方法

Abstract

本論文提出在軟體定義網路上設計並實作以來源為基礎的鏈結負載平衡多播方法。隨著越來越多的多播應用程式，如IPTV、videoconferencing等，IP多播已經逐漸地受到重視。然而，多播受限於分散式網路多播路由協定的效率不張而無法持續推廣。因此本論文設計一個集中式以SDN為基礎的多播架構，在控制器上實作群組管理模組、多播路由模組和網路狀態模組。我們建立群組管理與多播路由之間的介面，使得來源指定資訊可以被使用來路由封包給真正需要某來源的群組成員，以致於我們的多播路由能夠更有效率地使用網路頻寬。透過網路狀態的負載監控來驅動多播路徑選擇避免過於集中在某些鏈結，並採用Kou-Markowsky-Berman演算法來找出多播路由樹。最後，我們使用Mininet來評估我們基於來源多播路由性能。研究結果表明，我們的鏈路負載判定多播可以顯著提高吞吐量而只增加少量的多播路徑長度。研究結果還顯示維持群組資訊維持需要少量的花費。此外，90%的準備時間與啟動潛在時間分別在87毫秒與171毫秒內，兩者對於多播使用者感受而言是可被接受的。

In this thesis, we propose the design and implementation of a source-based mul-ticast approach with link-load balance in SDN. As more and more multicast applica-tions such as IPTV, videoconferencing, etc., IP Multicast has gradually been given more prominence. However, it is limited by the efficiency of multicast routing proto-col in a distributed network, so it is hard to continuously popularize it. Therefore, this thesis designs a centralized SDN-based multicast architecture with implementation of the Group Management Module, Multicast Routing Module, and Network State Mod-ule. We establish the interface between the Group Management Module and the Mul-ticast Routing Module, such that the source specific information can be used to route packets to particular group members which need a specific source. Such that our mul-ticast routing is able to more efficiently use the bandwidth of the network. The Net-work State Module monitors links’ load to drive the multicast routing to avoid the congested links. The Kou-Markowsky-Berman algorithm is adapted to find the mul-ticast routing tree. Finally, we use Mininet to evaluate the performance of our source-based multicast routing. The results show that our link-load awarded multicast can improve throughput significantly with increasing the less multicast path length. The results also show the group information maintenance takes little overhead. Fur-thermore, the 90% setup time is within 87ms and 90% of startup latency time is within 171ms. Both are acceptable for multicast in user experience.