VPN (Virtual Private Network)是個透過shared infrastructure將兩個不同的site連接起來的技術，也就是說企業不必再用昂貴的專線，而是利用公眾網路便能與遠處的分公司建置屬於企業內部的網路，又加上做為核心網路技術的MPLS (Multiprotocol Label Switching)堀起，MPLS VPN便逐漸成為熱門的討論議題，其中又以Layer 2 MPLS VPN的VPLS (Virtual Private LAN Service)最為受到青睞。在建置VPLS服務時，PE (Provider Edge)路由器是一個不可或缺的重要裝置，它幾乎掌管了所有VPLS重要的運作，包括路徑的建立、客戶訊框的轉送、群組資訊的維護…等。而在實現這樣一個裝置時，大致可分為control plane和data plane來討論，control plane主要負責在傳送客戶的資料訊框前，做好路徑的建立以及客戶資訊的維護，接著data plane便能依照control plane建立好的路徑來做資料訊框的傳送。而本論文主要是在探討control plane在運作中會出現的一些問題，進而提出虛擬私有網路管理模組(VPN manager)這個運作方塊來做為解決方案，以期能完成PE路由器control plane的正常運作。

Virtual Private Network (VPN) is a technology used to connect remote sites through shared infrastructure. Instead of the expensive leased line, enterprise has a better choice to construct its Intranet with VPN. With the advent of Multiprotocol Label Switching (MPLS) technology, MPLS VPN has become a hot topic. Especially, VPLS (Vritual Private LAN Service) is one of the most promising MPLS VPN technologies. When building a VPLS environment, PE router plays an important role. It performs almost all VPLS operations which include establishing paths, forwarding customer’s frames, maintaining member’s information, and so on. Functions in PE can be divided into control plane and data plane for implementing it. The main operation in the control plane contains setting up paths and maintaining information for each VPN group so that in data plane customer’s data frame can be forwarded according to the rule made by the control plane. The thesis mainly discusses some operation issues that appear in the control plane, and proposes a new function block, VPN manager, as a solution to maintain normal functioning of PE’s control plane.

第一章 簡介 1
第二章 虛擬私有區域網路服務 (VPLS) 3
2.1 MPLS VPN基礎架構 3
2.2 Martini 4
2.3 VPLS 6
2.3.1 Overview of Layer 2 MPLS VPN 6
2.3.2 VPLS 8
2.3.2.1 Control plane 8
2.3.2.2 Data plane 10
第三章 虛擬私有網路管理模組 (VPN Manager) 13
3.1 VPN Manager的由來以及Control Plane架構 13
3.2 VPN Manager處理流程 16
3.2.1 資料結構 16
3.2.2 Tunnel相關處理流程 18
3.2.3 VPN運作相關處理流程 28
第四章 功能驗證 39
4.1 使用者指令說明 39
4.2 與LDP的互動測試 40
第五章 結論 58
Reference 59

[1] E. C. Rosen and Yakov Rekhter, "BGP/MPLS VPNs", draft-ietf-l3vpn-rfc2547bis-03.txt, Work in Progress, October 2004.
[2] L. Martini, "Transport of Layer 2 Frames Over MPLS", draft-martini-l2circuit-trans-mpls-16.txt, Work in Progress, February 2005.
[3] L. Martini, "Encapsulation Methods for Transport of Layer 2 Frames Over IP and MPLS Networks", draft-martini-l2circuit-encap-mpls-09.txt, Work in Progress, February 2005.
[4] K. Kompella, "Layer 2 VPNs Over Tunnels", draft-kompella-l2vpn-l2vpn-00.txt, January 2004.
[5] K. Kompella and Y. Rekhter, "Virtual Private LAN Service", draft-ietf-l2vpn-vpls-bgp-05.txt, Work in Progress, April 2005.
[6] M. Lasserre and V. Kompella, "Virtual Private LAN Services over MPLS", draft-ietf-l2vpn-vpls-ldp-06.txt, Work in Progress, February 2005.
[7] H. Ould-Brahim, E. C. Rosen, and Y. Rekhter, "Using BGP as an Auto-Discovery Mechanism for Layer-3 and Layer-2 VPNs", draft-ietf-l3vpn-bgpvpn-auto-06.txt, Work in Progress, June 2005.
[8] J. Heinanen and G.. Weber, "Using RADIUS for PE-Based VPN Discovery", draft-ietf-l2vpn-radius-pe-discovery-01.txt, Work in Progress, February 2005.
[9] Y. T. Chen, "Extension of VPLS Signaling Protocol for Establishing Pseudo-Wire", July 2005.