| 摘要: | 隨著網路日新月異的發展，每日擁有成千上萬的網路設備連上網，此外服務供應商也提供多元化的網路服務以滿足人們使用，而廣域網路是網路流量的匯集地，在這龐大的訊務傳輸下導致了網路壅塞的現象，因此差異化的網路傳輸是必要的。傳統多重協定標籤交換（Multi-Protocol Label Switching, MPLS）架構中透過標籤分配協定（Label Distribution Protocol, LDP）和基於流量工程擴展的資源預留協議（Resource Reservation Protocol, RSVP-TE）來實現差異化網路傳輸，由於需要長時間的控制訊號以及路由器需維護龐大的轉發狀態，致使不必要的頻寬消耗、維護成本龐大和低擴展性。而分段路由（Segment Routing）技術彌補了這些缺陷，不只簡化了控制訊號，還透過源路由（Source Routing）概念改善了中間路由器維護轉發狀態的成本，分段路由被稱為「下一代的MPLS」。
本研究將實現分段路由技術，並結合軟體定義廣域網路（Software Defined Wide Area Network），藉由集中化與可程式化的優勢來開發路由策略，此外研究也將提出QoS-PLUTO（Quality of Service-Routing Policy Using Segment Routing）概念，針對Bandwidth/Delay Sensitive、Bandwidth Sensitive和Delay Sensitive流量種類給予不同的路由策略，不只減少網路壅塞的發生，也增加網路資源使用率。另外不同應用服務存在著不同QoS需求，這往往影響著客戶端的使用體驗，因此本研究也將加入此因素作為路徑選擇的考量，給予服務品質的保證。
;With the rapid development of the Internet, there are tens of thousands of network devices connected to the Internet every day. In addition, service providers provide diverse services to satisfy human′s need. The wide area network become a gathering place for network traffic. Due to huge traffic transmission, network congestion is often caused, so differentiated traffic transmission is necessary. In the traditional multi-protocol label switching （MPLS） architecture, Label Distribution Protocol （LDP） and Resource Reservation Protocol （RSVP-TE）are used to achieve differentiated traffic transmission. MPLS needs long time control signal and maintains huge forwarding state of traffic, so that it leads to unnecessary bandwidth consumption, huge maintenance cost and low scalability. Segment routing technology makes up for these shortcomings, it not only simplifies the control plane, but also improves the cost of maintaining the forwarding state of the intermediate router through the concept of source routing. Segment Routing is called "Next Generation of MPLS".
This paper will implement segment routing and combine with software defined networking（SDN）to develop routing strategies with SDN’s advantages of centralization and programmability. In addition, the paper will propose QoS-PLUTO （Quality of Service-Routing Policy Using Segment Routing）, giving differentiated routing strategies for both of bandwidth and delay sensitive, bandwidth sensitive and delay sensitive traffic. The proposed mechanism avoids the occurrence of network congestion. Furthermore, different application services have different QoS requirements, which often affect the experiences of users. Therefore, this paper will also add this factor as a consideration of path selection to give a guarantee of service quality. |
