MToS: Multi-Tenant Network Over Software Defined Networking

MToS, a multi-tenant network service is designed and implemented under Software-Defined Network (SDN) environment. One of the solutions to establish multi-tenant network in non-SDN environment is Multi-Protocol Label Switching Virtual Private Network that involves numerous and complicated protocols to be configured prior to the establishment of multi-tenant network. With SDN, it opens new opportunities to create multi-tenant networks that are less complicated, more automated, and lower implementation cost 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 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, and implemented in Python and runs on top of Ryu SDN framework.