A virtual network (VN) contains a collection of virtual nodes and links assigned to underlying physical resources in a network substrate. VN migration is the process of remapping a VNs logical topology to a new set of physical resources to provide failure recovery, energy savings, or defense against attack. Providing VN migration that is transparent to running applications is a significant challenge. Efficient migration mechanisms are highly dependent on the technology deployed in the physical substrate. Prior work has considered migration in data centers and in the PlanetLab infrastructure. However, there has been little effort targeting an SDN-enabled wide-area networking environment - an important building block of future networking infrastructure. In this work, we are interested in the design, implementation and evaluation of VN migration in GENI as a working example of such a future network. We identify and propose techniques to address key challenges: the dynamic allocation of resources during migration, managing hosts connected to the VN, and flow table migration sequences to minimize packet loss. We find that GENIs virtualization architecture makes transparent and efficient migration challenging. We suggest alternatives that might be adopted in GENI and are worthy of adoption by virtual network providers to facilitate migration.
تحميل البحث