MToS: 利用軟件定義網路之多用戶網路

Abstract

MToS，多用戶網路服務是應用設計和軟件定義網路（SDN）的環境下實現的。 SDN已經成為一個熱門的研究課題無論是在學術界和工業界的境界，它提供了在成本方面的效率以及管理和網路設備的控制。多協議標籤交換虛擬專用網路（MPLS VPN）是解決方案建立在非SDN環境下多用戶網路中的一個。但是在建立多用戶網路之前，它涉及許多複雜的協議需要進行配置。SDN，它會打開新的機會，創建多用戶網路不那麼複雜，更加自動化，並經由SDN網路商品，使多用戶網路設備實施更便宜。 MToS歸類OpenFlow的交換機分為三個層級，其中匹配字段和流表目的操作取決於不同層級的交換機。因此，網路流量轉發可達擴展性。MToS通過流表營運每個用戶並且提供用戶隔離，使用用戶端的MAC地址作為其流表重定和封包頭表的修改。網路流量轉發是經由Edge交換機之間的轉發達成，其中是通過Edge MAC地址及封包頭表修改而實現的，並且Edge交換機的工作原理是利用ARP Proxy爲用戶端主機服務。相較於MPLS VPN，MToS建構和營運用戶網路只需要用戶基本信息。以SDN集中性的全球網路信息優勢，MToS運營增加了IP地址管理的自動化和最短路徑計算的路線。MToS開發基於 ii OpenFlow的1.3版標準，並用Python編程語言實現的，它運行在Ryu SDN架構之上。 關鍵字：SDN，多用戶網路，MPLS VPN，OpenFlow，Ryu。

MToS, a multi-tenant network application is designed and implemented under Software-Defined Network (SDN) environment. SDN has become a popular research topic both in academia and industry realm, it offers efficiency in term of costs as well as management and control of networking devices. Multi Protocol Label Switching Virtual Private Network (MPLS VPN) is one of the solutions to establish multi-tenant network in non-SDN environment; it involves numerous and complicated protocols need to be configured prior to the establishment of multi-tenant network. With the emerging SDN, it opens new opportunities to create multi-tenant network that are less complicated, more automated, and cheaper implementation via SDN commodity devices. MToS categorizes OpenFlow switches into three hierarchies, where matching fields and actions in flow entries are different depending on the switch hierarchy. Therefore, traffic forwarding can be scalable. MToS provides tenant isolation through dedicate flow table associated with each tenant, and tenant MAC address as the identifier which is used in flow table redirection and packet header modification. Traffic forwarding between Edge switches is achieved through Edge MAC address as the identifier which is used in packet header modification, and Edge switch iv serves as ARP Proxy for tenant end hosts. Comparing to MPLS VPN, MToS only requires essential information about tenants to construct a multi-tenant network. By taking advantage of SDN centralized global network information, MToS adds automations of IP address management and shortest path routes calculation. MToS is developed based upon OpenFlow version 1.3 standards, and implemented in Python programming language; it runs on top of the Ryu SDN framework. Keywords: SDN, multi-tenant network, MPLS VPN, OpenFlow, Ryu