臺灣博碩士論文加值系統

Differentiated Services (DiffServ)區分服務是由IETF提出，以低成本架構在網際網路協定的網路(IP networks)中提供服務品質(QoS)。區分服務架構包含兩個主要部分：在邊際節點執行交通流量調節及以單次跳躍行為機制在中心節點續傳。我們可以經由各種建立的方塊圖來瞭解交通流量調節器的各個組成，例如分類器計量器(Meter)、標記器(Maker)、節流器(Policer)等等。這篇論文著重在區分服務的研究，同時也幫助了我們瞭解在實現區分服務路由器時可以有哪一些設計上的選擇。
區分服務架構中，複雜的分類及調節功能只於網路邊界點執行，也因此大大減輕核心路由器比例尺之問題。但是它仍然需要控制信號通信協定(signaling protocol)來得到服務品質保證。由於資源預留通信協定目前已廣泛的獲得業界的支持，正適合用於提供端點到端點的服務保證，而服務品質通常經由延遲的表現來驗證。我們的結果顯現出，資源預留通信協定導入區分服務網路之中不只解決了比例尺的問題，更得到了服務品質的保證。

Differentiated Services (DiffServ) is proposed by IETF as a low-cost architecture to provide Quality of Service in IP networks (IP-QoS). The DiffServ architecture consists of two key components: traffic conditioning at the edges and Per Hop Behavior (PHB) at the core. Traffic conditioners are realized with various building blocks such as classifier, meter, marker, policer etc. This thesis is focused on the study of DiffServ. The results of the study help us to understand the design choices for some of the DiffServ architecture building blocks in a DiffServ-enabled router.
DiffServ has good scalability in the backbone but it needs a signaling protocol to get guaranteed service. Resource reSerVation Protocol (RSVP), a signaling protocol for end-to-end guaranteed service and extensively supported by industry, is a good choice to be deployed with DiffServ to verify the delay performance. Our simulation results show this way of deployment not only solves the problem of QoS scalable because of DiffServ but also gets the QoS guarantee.

ABSTRACT (in Chinese)I
ABSTRACT (in English)II
CONTENTSIII
LIST OF FIGURESⅤ
LIST OF TABLESⅦ
CHAPTER 1 INTRODUCTION1
1.1 Introduction1
1.2 Motivation and our Approach2
1.3 Thesis Outline3
CHAPTER 2 RELATED WORK4
2.1 Internet Quality of Service (QoS)4
2.1.1 Guaranteed service 4
2.1.2 Integrated service5
2.1.3 Problems with Integrated Services5
2.2 Resource reSerVation Protocol6
2.3 H.263 Video Conferencing as Simulation Traffic Source8
2.3.1 Introduction8
2.3.2 Overview of H.263 video compression8
2.4 Simulation Environment: An Over View of OPNET (Optimized Networking Engineering Tool)9
CHAPTER 3 Differentiated Services (DiffServ)10
3.1 DiffServ Architecture10
3.2 DS Domains and DS Regions11
3.3 The DS Codepoint (DSCP)13
3.4 Assured and Expedited Forwarding PHBs14
3.5 Traffic Classifications and Conditioning15
3.6 Classification Operations17
3.7 Metering Operations18
3.8 Discard Behavior in Queuing20
CHAPTER 4 SIMULATION SETUP AND RESULTS22
4.1 Implementing a DiffServ-enable router23
4.2 Traffic from Senders to Receiver26
4.3 Functionalities of DiffServ27
4.3.1 Simulation setup27
4.3.2 Simulation results27
4.4 RSVP as QoS Signaling for DiffServ Networks32
4.4.1 Simulation Setup32
4.4.2 Simulation Results33
CHAPTER 5 CONCLUSIONS34
REFERENCES35

[1]. R. Braden et al., “Resource Reservation Protocol (RSVP) ─ Version 1 Functional Specification,” RFC 2205, Sept. 1997.
[2]. R. Braden, D. Clark, and S. Shenker, “Integrated Services in the Internet Architecture: An Overview,” RFC 1633, July 1994.
[3]. S. Blake et al., “An Architecture for Differentiated Services,” RFC 2475, Dec. 1998.
[4]. J. Heinanen, et al., “Assured Forwarding PHB Group,” RFC 2597, Jun. 1999.
[5]. V. Jacobson, et al., “An Expedited Forwarding PHB,” RFC 2598, Jun. 1999.
[6]. T. Worster, et al., “Guaranteed Rate in Differentiated Service,”
draft-worster-diffserv-gr-00.txt, Jun. 1998.
[7]. S. Floyd and V. Jacobson, “Random Early Detection gateways for congestion avoidance,” IEEE/ACM Trans. on Networking, vol. 1, pp. 397—413, Jan. 1993.
[8]. Q. Wang, et al., “A PHB Reservation Mechanism in DiffServ Network,” IEEE/ACM Trans. on Networking, 2000.
[9]. S. Schenker, C. Partridge, and R. Guerin, “Specification of Guaranteed Quality of Service,” Internet Draft, Aug. 1996.
[10]. A. Parekh and R. Gallagher, “A Generalized Processor Sharing Approach to Flow Control ─ The Single Node Case,” IEEE/ACM Trans. Networking, vol. 1, no. 3, pp. 366—57, Mar. 1993.
[11]. A. Parekh and R. Gallagher, “A Generalized Processor Sharing Approach to Flow Control ─ The Multiple Node Case,” IEEE/ACM Trans. Networking, vol. 2, no. 2, pp. 137—50, Feb. 1996.
[12]. IETF home page, http://www.ietf.cnri.reston.va.us
[13]. Integrated Services Charter, http://www.ietf.org/html.charters/intserv-charter.html.
[14]. K. Rijkse, “H 263: Video coding for low-bit-rate communication,” IEEE Communications Magazine, 34(12) pp. 42-45, Dec. 1996.
[15]. http://wwww-tkn.ee.tu-berlin.de/reseach/trace/trace.html.
[16]. ITU-T, Recommendation H.261, video codec for audio-visual services at 64 - 1920 kbit/s, 1993.
[17]. A. Puri and T Chen, Multimedia Systems, Standards, and Networks. Marcel Dekker New York, 2000.
[18]. F. Baker, D. Black, S. Blake, and K. Nichols, “Definition of the Differentiated Services Field (DS Field) in theIPv4 and IPv6 Headers,” RFC 2474, Dec. 1998.