植基於GPON之 OpenFlow 虛擬交換機設計與實現

Design and Implementation of GPON-based OpenFlow Virtual Switch

吳明書(Ming-Shu Wu)

指導教授 ： 李詩偉

國立中正大學/工學院/通訊工程學系/碩士(2015年)

摘要

GPON是目前重要的接取網路技術之ㄧ，在一個GPON網路中可分成OLT (Optical Line Termination)與ONU (Optical Network Unit)兩種設備，OLT以及ONU間的距離可達到20公里。軟體定義網路(Software Defined Network, SDN)是一種新興的網路技術，在SDN網路中藉由控制層與資料層分離達到更高的網路控制與管理能力。本論文即在研究如何使用GPON被動光纖網路建置一個虛擬軟體定義網路(Software Defined Network, SDN)交換機，以達到具備使用SDN控管分佈於各地的接取點。依照我們的設計，OpenFlow Controller能視本GPON系統如同一台真正的OpenFlow交換機，使用者可以使用標準的OpenFlow協定來對此虛擬交換機進行操作。本研究中我們提出此虛擬交換機的架構並設計ㄧproxy server以介接OpenFlow Controller以及GPON OMCI管理系統，在研究的最後我們實現了本設計，並驗證虛擬交換機與控制器連結、各種OpenFlow 之flow entry 設定以及修改、虛擬交換機統計值讀取以及動態頻寬限定等功能，實驗結果顯示，本系統可快速設定虛擬交換機並能動態調整頻寬，達到高彈性的網路控制與管理目的。

關鍵字

被動光纖網路 ； 軟體定義網路

並列摘要

Software Defined Networking (SDN) is an emerging technology to enhance flexible control on network services through abstraction of lower-level functionality. In SDN, the control plane and data plane are separated. The controller directly manages SDN aware devices through well defined interface. The programmable and central controlled features of SDN enable the controller to efficiently utilize network resources and to facilitate QoS differentiation on services through network-wide optimization. OpenFlow is one of the protocols to realize SDN. Besides electrical L2/L3 switches, Optical cross-connect (OXC) switch is also included in the latest OpenFlow specifications. GPON has proven to be a successful technology for providing cost effective Internet access for users with distance up to 20 km from the central office. GPON is famous on its network management capability. Besides providing physical OAM for timing critical signaling, GPON also uses OMCI to perform statistical data collection, service provisioning, and fault management. GPON can accurately control bandwidth usage for each subscriber via dynamic bandwidth allocation (DBA). Although GPON is famous on its management capability, the configuration and service provisioning are basically static. Since GPON is not a switch, unlike OXC, it is not included in OpenFlow standard. In this work, we abstract the whole GPON as an OpenFlow enabled switch through the implementation of an embedded GPON proxy residing in the OLT. The proxy simultaneously interacts with the OpenFlow controller and the GPON OMCI module. A standard OpenFlow controller can dynamically control a GPON virtual switch the same as a real switch. However, the former might consist of multiple sites spreading in diverse locations. We have conducted experiments to evaluate the performance of the virtual switch. Experimental results show that the GPON virtual switch can realize most functions defined by OpenFlow. Its performance on configuration time, bandwidth control, and switch status monitoring are within similar level compared to a real OpenFlow switch.

並列關鍵字

OpenFlow ； GPON ； SDN

參考文獻

[4] ITU-T Gigabit-capable Passive Optical Networks (GPON).

General characteristics. ITU-T G.984.1, 2008.

[5] ITU-T Gigabit-capable Passive Optical Networks (GPON).

[6] ITU-T Gigabit-capable Passive Optical Networks (GPON).

Transmission convergence layer specification. ITU-T G.984.3, 2008.