臺灣博碩士論文加值系統

隨著網際網路的盛行及智慧家電與3G無線通訊時代的到來，使得IPv4位址不足的問題逐漸受到重視，根據亞太網路資訊中心發布的IPv4 Address Consumption Model可以預估在2010至2015年之間IPv4位址將會消耗殆盡，即使目前有網路位址轉換(Network Address Translation, NAT)與無等級內部路由(Classless InterDomain Routing, CIDR)等技術來暫時解決IP位址不足的情況。在1995年時Internet Engineering Task Force (IETF)，制定了下世代的網際網路協定IPv6來解決IPv4位址不足的問題並且針對在IPv4的不足處進行補強與改善，特別是在服務品質(QoS)方面在IPv6表頭中加入了Traffic Class與Flow Label欄位做為QoS方面的應用。
雖然在IPv4已經有用Differentiated Service Codepoint (DSCP)欄位來做為差異性服務(DiffServ)。但在使用差異性服務來做為End-to-end QoS保證的機制下，網域中的所有路由器都必須提供差異性服務的功能，其主要原因在於差異性服務的架構是用邊緣路由器來給予封包不同的對待等級，以後再由核心路由器依據Per Hop Behaviors (PHBs)來給予不同等級的對待，因此封包有可能會經過網域中的任何一台路由器。此外，邊緣路由器若採用5-tuple(source and destination address, ports, and protocol)做為分類的依據，則往往容易造成邊緣路由器上的負擔。基於上述的考量，本文提出使用Traffic Class與Flow Label的End-to-end QoS機制來減輕邊緣路由器在分類上的負擔並且克服網域中所有路由器必須提供差異性服務能力的限制。

With the rapid growth of internet, Information Appliances (IA), and 3G wireless communications, the problem of insufficient IPv4 address was considered gradually. According to the IPv4 address consumption model which was issued by Asia-pacific Network Information Center (APNIC), the IPv4 address space will be exhausted about 2010-2015. Although Network Address Translation (NAT) and Classless Inter-Domain Routing (CIDR) can solve the situation temporarily, but the problem still is not overcome thoroughly. Therefore Internet Engineering Task Force (IETF) has promoted a next generational internet protocol IPv6 in 1995 to solve the above problem. Besides IPv6 enhances and improves the insufficient IPv4 address in QoS aspect. IPv6 especially adds Traffic Class and Flow Label fields in its packet header for QoS applications.
Although Differentiated Service Codepoint (DSCP) field in IPv4 packet header is used for DiffServ, but all routers must provide DiffServ capacity in the internet domain for End-to-end QoS provisioning. The reason is edge routers aggregate and mark packets for differentiated classes and core routers only treat packets by Per Hop Behaviors (PHBs) for differentiated services. Therefore packets may be passed by any router in internet domain. Besides edge routers should manage traffic with 5-tuple (source and destination addresses, ports, protocol) for classification, it would make edge routers in heavy load. On the basis of above consideration, this paper proposes an End-to-end QoS mechanism by using Traffic Class and Flow Label to reduce the load of classification in edge routers and overcome all routers have to provide DiffServ capacity in the internet domain.

摘 要 i
Abstract ii
致 謝 iii
目 錄 iv
圖目錄 v
第一章 前 言 1
第二章 背 景 6
2.1 Quality of Service 6
2.1.1 IntServ 6
2.1.2 DiffServ 8
2.1.3 MPLS 12
2.1.4 IntServ, DiffServ, and MPLS 14
2.2 Internet Protocol Header 15
2.3 Flow Label 18
2.3.1 Specification of IPv6 Flow Label 18
2.3.2 A Scalable Architecture for End-to-end QoS Provisioning 20
2.3.3 Hybrid Approach for IPv6 QoS 22
第三章 Proposed QoS Mechanism for IPv6 27
3.1 Bit Patterns for Flow Label 27
3.2 FLMT and FLFT 28
3.3 Scenario for QoS Mechanism 29
3.4 Features 34
第四章 實驗模擬與討論 36
4.1 模擬環境 36
4.2 模擬結果與分析 37
4.2.1 Time Sliding Window Three Color Marker (TSWTCM) 38
4.2.2 Two Rate Three Color Marker (TRTCM) 42
4.2.3 Single Rate Three Color Marker (SRTCM) 46
第五章 結論與未來工作 51
參考文獻 53

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