Distributed Resource Management and Admission Control in Budget-Based QoS Management for All-IP Core Networks

通訊與資訊科技的大幅進步，電信自由化帶來的激烈競爭，以及網際網路的蓬勃發展，刺激大量多媒體網路資訊的流通，為了因應此種趨勢，網路提供者已趨向合併數據及電信網路朝單一的All-IP網路方向發展。為了保證時效性服務在All-IP網路上的品質，網路服務品質(QoS)已成為All-IP網路的主要研究議題。不同的網路應用各有不同的特性與需求；對於那些比較不注重傳輸延遲時間的應用，增加網路頻寬或許就已足夠應付需求，但是對於那些具有互動特性 (interactive)、重視傳輸延遲時間的應用，像VoIP，除了增加網路頻寬外，All-IP網路必須提供服務品質保證才能獲得網路營運者的支持。本研究團隊設計一個管理架構，在此架構上提供完整的End-to-End QoS保證，以符合All-IP網路上各種不同服務需求。本文中另外提出以預先批購頻寬的方式進行核心網路資源規劃，根據需求預測，考量批購成本期望值，決定出適當之頻寬預購值。於執行時段提出數個允入控制資源不足解決方案，並且配合執行時段頻寬管理機制，掌握頻寬使用情形，以達到順利允入網路訊務之目的。最後於NS2平台以實驗模擬的方式，評估本文中所提出之預先批購頻寬與執行時段頻寬管理機制，從結果中我們發現本研究所提出之頻寬預購方法可以有效預防因為預測誤差所造成之資源不足現象，配合執行時段頻寬管理機制可根據執行時期之資源使用狀況，在資源缺乏時提前進行頻寬補充，以順利允入訊務，提升使用率。Because of great progress of communication and computer technology, aggressive deployment of broadband fiber optical network, advance of Internet technology, and the global standardization of IP technology, the telecommunication industry is moving toward a converged network, which uses a single global IP based packet-switching network to carry all types of network traffics. In these types of network traffics, different traffic types require corresponding service to ensure end- to-end quality. For carrying all types of network traffics on All-IP network, BBQ (Budget-Based QoS) research group propose a QoS system architecture to provide end-to-end QoS guarantee. In this thesis, basing on BBQ QoS system, we propose resource pre-planning mechanism to management core network. According to demand forecast from historical data and considering pre-planning cost, pre-planning mechanism will find optimal policy to reduce management cost. Besides resource pre- planning, we also propose several solutions to avoid resource shortage at run-time. Through intensive evaluation in network simulatior-2(ns2), we demonstrate that our resource pre-planning can minimize resource cost and cover some forecasting error. And run-time resource management can maintain reasonable in-hand resource at run-time to reduce the effect of resource shortage