IPv6改善了許多IPv4所欠缺的優點，尤其128 位元的定址能力，使得IP位址不再缺欠。但IPv6在發展階段必須與IPv4共存，網路服務提供者(ISP)須提供IPv4 及 IPv6兩種網路服務，幾種互通機制於是產生，其中有一種架構在IPv4 MPLS 網路之上能讓IPv6 網路透通的方式，ISP 只需在MPLS 邊際路由器啟動Dual Stack及MP-BGP等設定，不需增加任何新設備，是種低成本且方便的作法，稱為6PE (Connecting IPv6 Islands over IPv4 MPLS using IPv6 Provider Edge Routers )網路。 目前的6PE 在規範中並不支援服務品質(QoS)，本論文的主要研究重點在探討如何使6PE網路具備QoS，並考量IPv6 流量封包的不同服務等級特性，將網路資源做有效分配。論文中採用DSCP (DiffServ Code Point) 貫通6PE網路中的IPv6 及MPLS 網路，並使用標準對應(Mapping)延續封包的服務等級，以及引用IPv6 標頭的Flow Label 加快訊流的繞送速度，以期達到不同服務等級的需求。 經由模擬軟體操作改變網路環境參數(Data rate、DSCP及Flow Label)及設定不同的網路狀況(例如網路雍塞)，觀察各個狀況之下的流量(Throughput )及端對端點回應時間(Round Trip Time, RTT)，當封包具備較高的DSCP或Flow Label 時，其Throughput 獲得保障且RTT 相對較小也較穩定。模擬結果證實了6PE網路具備QoS的可行性及其效益。 IPv6 improves a lot from IPv4, especially in addressing of 128-bits, increases the IP address space tremendously. In the developlement of IPv6 , it needs to co-work with IPv4. The ISP has to provide both service of IPv4 & IPv6. One of them basing on IPv4 MPLS network makes IPv6 work, ISP only adjusts the setting of routers and activate Dual Stack & MP-BGP with no additional equipment required and saving cost. Thus, it’s called 6PE (Connecting IPv6 Islands over IPv4 MPLS using IPv6 Provider Edge Routers ). The 6PE doesn’t support QoS in the current regulations, and this research emphasizes on how to make 6PE working with QoS, within consideration of different package service of IPv6. Thus network resouces will be re-allocated efficiently. In the research , we use DSCP (DiffServ Code Point) to bridge IPv6 & MPLS networks of 6PE, and also apply standard mapping extended package, thus quote IPv6’s Flow Label to increase the stream passing, and it will fit different service needs. From the operation with simulated software changing network environment References (Data rate、DSCP、Flow Label) and seting some network situations (ex: network Congestion), we can observe the throughput under controlling situations and Round Trip Time (RTT). When the package carrying more DSCP or Flow Label, the results of throughput are assured and RTT becomes shorter and more stable. Simulation results prove that possibility and efficiency of QoS on 6PE Networks.
