吳靜雄臺灣大學：電信工程學研究所白威莉Sreedevi, ParuvelliParuvelliSreedevi2007-11-272018-07-052007-11-272018-07-052005http://ntur.lib.ntu.edu.tw//handle/246246/58638The explosive growth of the internet demands more and more bandwidth, in particular for the core network. The rapid advance of wavelength division multiplexing (WDM) technology provides to exploit the huge capacity of optical fiber. According to the present day requirements encourag to study internet traffic supporting with quality of service (QoS). Since the future integrated internet will require differentiated services, where applications such as video conferencing and distance learning will demand a higher QoS than file transfer or web browsing. Wavelength converters improve network blocking performance as well as QoS management. Efficient buffer management schemes for QoS are necessary to minimize probability of packet loss (PPL). The introduction of space priorities is an efficient buffer management scheme in which the buffers are controlled by a threshold. In this thesis, the study in terms of PPL comparing the two conventional buffer management strategies, introducing a threshold in primary buffer (PB) and recirculation buffer (RB) of feedback (FB) type WDM optical routers are presented. We compare the switching performance between the two partial buffer sharing (PBS) strategies. Through the simulation, it is found that the PBS strategy in PB is not an efficient scheme for both asynchronous and synchronous WDM optical routers. The PBS strategy in PB leads to a new scheme by reducing the number of re-circulations for low priority (lp) packets, which is named as constrained threshold in PB (CTPB). PBS in RB shows good performance compared to PBS in PB strategy but the new strategy CTPB dominates the two conventional strategies in attaining differentiated services.Chapter 1. Introduction 1 1.1 Back Ground and Motivation --------------------------------------------------------- 1 1.2 Goal of the Thesis ------------------------------------------------------------------------ 4 1.3 Organization of the Thesis ------------------------------------------------------------- 5 Chapter 2. Fundamentals 7 2.1 Introduction to Switching --------------------------------------------------------------- 7 2.2 Optical Switch Architectures ----------------------------------------------------------- 8 2.3 Slotted and Un-slotted Networks ------------------------------------------------------ 9 2.4 Contention Resolution Schemes ------------------------------------------------------- 10 2.4.1 Optical Buffering -------------------------------------------------------------------- 11 2.4.2 Deflection Routing ------------------------------------------------------------------ 12 2.4.3 Exploiting the Wavelength Domain ----------------------------------------------13 2.5 Optical Burst Switching ---------------------------------------------------------------- 14 2.6 Buffer Management for QOS --------------------------------------------------------- 15 2.6.1 End-to-End QoS Levels ----------------------------------------------------------- 15 2.7 Self-Similarity and Long-Range Dependence ------------------------------------- 16 Chapter 3. Performance Analysis of Asynchronous and Synchronous Feedback WDM Optical Routers under Variable Packet Length Self-Similar Traffic 21 3.1 Introduction ------------------------------------------------------------------------------ 21 3.2 Architecture of WDM Optical Routers --------------------------------------------- 22 3.2.1 FF Type Switch ---------------------------------------------------------------------- 23 3.2.2 FB Type Switch ---------------------------------------------------------------------- 24 3.3 Performance Analysis and Simulation Results ------------------------------------ 28 3.3.1 Performance Evaluation of FF and FB Type WDM Optical Routers ---- 29 3.3.2 Optimal Delay Line Unit (DLU) in Asynchronous and Synchronous Type WDM Optical Routers --------------------- 34 3.4 Summary --------------------------------------------------------------------------------- 38 Chapter 4. Performance Evaluation of Prioritized Buffer Management Strategy in Primary Buffer 39 4.1 Introduction ------------------------------------------------------------------------------ 39 4.2 Partial Buffer Sharing (PBS) Strategy --------------------------------------------- 40 4.3 Partial Buffer Sharing in PB --------------------------------------------------------- 41 4.4 Performance Evaluation of PBS Strategy in PB ---------------------------------- 42 4.4.1 Evolution of Constrained Threshold in PB ------------------------------------ 45 4.4.2 Comparing CTPB and PBS Strategy in PB ------------------------------------ 47 4.5 Summary ---------------------------------------------------------------------------------- 52 Chapter 5. Performance Evaluation of Prioritized Buffer Management Strategy in Re-circulating Buffer 55 5.1 Introduction ---------------------------------------------------------------------------------- 55 5.2 Partial Buffer Sharing in RB ------------------------------------------------------------- 55 5.2.1 Comparative Evaluation of PBS in RB with PBS in PB ------------------------ 56 5.2.2 Comparing PBS in RB Strategy with CTPB ---------------------------------------62 5.3 Summary -------------------------------------------------------- -----------------------------68 Chapter 6. Conclusion 69 Bibliography 732301915 bytesapplication/pdfen-US光路由器非同步及同步可變長度Optical RoutersAsynchronous and SynchronousVariable-packet-lengththesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/58638/1/ntu-94-R92942106-1.pdf