| Network virtualization is aimed at establishing the logical virtual network isolated from each other on the bottom of the public physical network, each logical network can have their own unique address format, addressing strategy and control method. In traditional network architecture, to achieve complete network virtualization in the traditional network architecture, we must construct the virtual network on the private closed network equipment which have proprietary control software, meanwhile, control and manage the virtual network. To achieve this goal requires a certain upgrade or retrofit of the network equipment, and it also need to build a corresponding proprietary software. SDN is a novel paradigm of network architecture. As one of the most typical SDN implementation technology, which is characterized by the separation of control and forwarding, centralized control, open programmable interface and virtualized network layer, OpenFlow provide a new perspective for the realization of network virtualization. So far, a large number of OpenFlow based SDN network virtualization platform has been proposed. However,these network virtualization platforms only realize the virtualization of some network attributes.we put forward basic problem to design of network virtualization platform: all aspects function that a complete network virtualization platform have to implement,and it's architecture. On this basis, we analyze function characteristics of the most representative centralized network virtualization platform. Among them, OpenVirteX(OVX) is a recently proposed centralized network virtualization platform, by decoupling the virtual network representation from the physical network representation, it realized topology, address space and control function of virtualization. However, OVX lack of host traffic isolation that is important feature that must be included in the complete network virtualization architecture.To solve this problem, we analyze the method to achieve host traffic classification and isolation in the existing network virtualization platform: if it use all the matching domain to archive host traffic classification, we have to define complex traffic types, and matching field rewriting in the data plane may cause crosstalk between virtual network traffic; if it use the label field to archive host traffic classification, all the network devices must support the corresponding label operation that will bring additional data plane overhead. Moreover, we combined with various matching field characteristics, and proposed a novel model of centralized networkvirtualization platform called single host multi-connection-OVX(SHMC-OVX) that using transport layer type and port number that is more stable in the forwarding plane as a basis of traffic classification. SHMC-OVX builds on the design of OVX, using Appport that is defined by OpenFlow transport layer fields realize 1: n mapping of host and virtual network, At the same time, redesigning the core processing logic of the three main OpenFlow messages: realizing OpenFlow message virtualization according to the mapping between host traffic flow and virtual network. In addition,we implement the polymerization of the service network by integrate multiple Appport. SHMC-OVX overcome the main problem of the OVX: single host can only connect to a single virtual network, and introduces a small traffic isolation overhead and data plane extra overhead. We mainly evaluate the function and performance of SHMC-OVX. Our functional verification show that SHMC-OVX has the ability that single host may connect to multiple virtual networks; Our performance verification show that, compared with OVX, the average time delay increment of SHMC-OVX is in acceptable range, and the control channel time delay of SHMC-OVX is increased by 0.381 ms compared with OVX. |
PDF Full Text Request